Remove warnings, use lambdas, use try-with, ...

83 files changed, 631 insertions, 855 deletions

diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/Constants.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/Constants.java
index 1d42285a..ee3da659 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/Constants.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/Constants.java
@@ -31,7 +31,7 @@ public class Constants {
         Pattern p = Pattern.compile("(\\d+).(\\d+).(\\d+)");
         Matcher m = p.matcher(appVersion);
 
-        int version[] = new int[] { 0, 0, 0 };
+        int[] version = new int[] { 0, 0, 0 };
         if (m.matches()) {
             version[0] = Integer.parseInt(m.group(1));
             version[1] = Integer.parseInt(m.group(2));
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/PodcastArrayAdapter.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/PodcastArrayAdapter.java
index 5e9b45b7..185ccb8c 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/PodcastArrayAdapter.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/PodcastArrayAdapter.java
@@ -1,5 +1,6 @@
 package de.luhmer.owncloudnewsreader.ListView;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -20,8 +21,8 @@ import de.luhmer.owncloudnewsreader.model.PodcastItem;
 
 public class PodcastArrayAdapter extends ArrayAdapter<PodcastItem> {
 
-    private LayoutInflater inflater;
-    private EventBus eventBus;
+    private final LayoutInflater inflater;
+    private final EventBus eventBus;
 
     public PodcastArrayAdapter(Context context, PodcastItem[] values) {
         super(context, R.layout.podcast_row, values);
@@ -30,6 +31,7 @@ public class PodcastArrayAdapter extends ArrayAdapter<PodcastItem> {
         //eventBus.register(this);
     }
 
+    @SuppressLint("SetTextI18n")
     @Override
     public View getView(final int position, View view, ViewGroup parent) {
         final ViewHolder holder;
@@ -55,32 +57,21 @@ public class PodcastArrayAdapter extends ArrayAdapter<PodcastItem> {
         });
 
 
-        holder.binding.flDownloadPodcastWrapper.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View view) {
-                holder.binding.flDownloadPodcastWrapper.setVisibility(View.GONE);
+        holder.binding.flDownloadPodcastWrapper.setOnClickListener(view1 -> {
+            holder.binding.flDownloadPodcastWrapper.setVisibility(View.GONE);
 
-                Toast.makeText(getContext(), "Starting download.. Please wait", Toast.LENGTH_SHORT).show();
+            Toast.makeText(getContext(), "Starting download.. Please wait", Toast.LENGTH_SHORT).show();
 
-                eventBus.post(new StartDownloadPodcast() {{ podcast = podcastItem; }});
-            }
+            eventBus.post(new StartDownloadPodcast() {{ podcast = podcastItem; }});
         });
 
-        holder.binding.flPlayPodcastWrapper.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View view) {
-                playPodcast(position);
-            }
-        });
+        holder.binding.flPlayPodcastWrapper.setOnClickListener(view12 -> playPodcast(position));
 
-        holder.binding.flDeletePodcastWrapper.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View view) {
-                if(NewsFileUtils.deletePodcastFile(getContext(), podcastItem.link)) {
-                    podcastItem.offlineCached = false;
-                    podcastItem.downloadProgress = PodcastItem.DOWNLOAD_NOT_STARTED;
-                    notifyDataSetChanged();
-                }
+        holder.binding.flDeletePodcastWrapper.setOnClickListener(view13 -> {
+            if(NewsFileUtils.deletePodcastFile(getContext(), podcastItem.link)) {
+                podcastItem.offlineCached = false;
+                podcastItem.downloadProgress = PodcastItem.DOWNLOAD_NOT_STARTED;
+                notifyDataSetChanged();
             }
         });
 
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/PodcastFeedArrayAdapter.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/PodcastFeedArrayAdapter.java
index f30dd4e9..d87363ff 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/PodcastFeedArrayAdapter.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/PodcastFeedArrayAdapter.java
@@ -18,8 +18,8 @@ import de.luhmer.owncloudnewsreader.model.PodcastFeedItem;
 
 public class PodcastFeedArrayAdapter extends ArrayAdapter<PodcastFeedItem> {
 
-    private LayoutInflater inflater;
-    private EventBus eventBus;
+    private final LayoutInflater inflater;
+    private final EventBus eventBus;
 
     public PodcastFeedArrayAdapter(Context context, PodcastFeedItem[] values) {
         super(context, R.layout.podcast_feed_row, values);
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/SubscriptionExpandableListAdapter.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/SubscriptionExpandableListAdapter.java
index de94ffb9..960247cd 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/SubscriptionExpandableListAdapter.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ListView/SubscriptionExpandableListAdapter.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -64,15 +64,14 @@ import static de.luhmer.owncloudnewsreader.ListView.SubscriptionExpandableListAd
 public class SubscriptionExpandableListAdapter extends BaseExpandableListAdapter {
     private final String TAG = getClass().getCanonicalName();
 
-    private Context mContext;
-    private DatabaseConnectionOrm dbConn;
+    private final Context mContext;
+    private final DatabaseConnectionOrm dbConn;
 
-    private ListView listView;
+    private final ListView listView;
 
     private ExpListTextClicked eListTextClickHandler;
 
-    private FavIconHandler favIconHandler;
-    private LayoutInflater inflater;
+    private final FavIconHandler favIconHandler;
 
     private ArrayList<AbstractItem> mCategoriesArrayList;
     private SparseArray<ArrayList<ConcreteFeedItem>> mItemsArrayList;
@@ -83,12 +82,12 @@ public class SubscriptionExpandableListAdapter extends BaseExpandableListAdapter
     private SparseArray<String> unreadCountFolders;
     private SparseArray<String> unreadCountFeeds;
 
-    private SharedPreferences mPrefs;
+    private final SharedPreferences mPrefs;
 
     public enum SPECIAL_FOLDERS  {
         ALL_UNREAD_ITEMS(-10), ALL_STARRED_ITEMS(-11), ALL_ITEMS(-12), ITEMS_WITHOUT_FOLDER(-22);
 
-        private int id;
+        private final int id;
         SPECIAL_FOLDERS(int id) {
             this.id = id;
         }
@@ -112,7 +111,6 @@ public class SubscriptionExpandableListAdapter extends BaseExpandableListAdapter
         this.favIconHandler = new FavIconHandler(mContext);
         this.mPrefs = prefs;
 
-        this.inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
     	this.mContext = mContext;
     	this.dbConn = dbConn;
 
@@ -246,38 +244,30 @@ public class SubscriptionExpandableListAdapter extends BaseExpandableListAdapter
         }
 
         viewHolder.binding.summary.setText(group.header);
-        viewHolder.binding.listItemLayout.setOnClickListener(new OnClickListener() {
+        viewHolder.binding.listItemLayout.setOnClickListener(v -> {
 
-            @Override
-            public void onClick(View v) {
+            long idFeed = group.id_database;
+            boolean skipFireEvent = false;
 
-                long idFeed = group.id_database;
-                boolean skipFireEvent = false;
-
-                if (group instanceof ConcreteFeedItem) {
-                    fireListTextClicked(idFeed, false, (long) ITEMS_WITHOUT_FOLDER.getValue());
-                    skipFireEvent = true;
-                }
-
-                if (!skipFireEvent)
-                    fireListTextClicked(idFeed, true, ((FolderSubscribtionItem) group).idFolder);
+            if (group instanceof ConcreteFeedItem) {
+                fireListTextClicked(idFeed, false, (long) ITEMS_WITHOUT_FOLDER.getValue());
+                skipFireEvent = true;
             }
-        });
 
-        viewHolder.binding.listItemLayout.setOnLongClickListener(new View.OnLongClickListener() {
+            if (!skipFireEvent)
+                fireListTextClicked(idFeed, true, ((FolderSubscribtionItem) group).idFolder);
+        });
 
-            @Override
-            public boolean onLongClick(View v) {
+        viewHolder.binding.listItemLayout.setOnLongClickListener(v -> {
 
-                long idFeed = group.id_database;
+            long idFeed = group.id_database;
 
-                if (group instanceof ConcreteFeedItem) {
-                    fireListTextLongClicked(idFeed, false, (long) ITEMS_WITHOUT_FOLDER.getValue());
-                } else {
-                    fireListTextLongClicked(idFeed, true, ((FolderSubscribtionItem) group).idFolder);
-                }
-                return true; //consume event
+            if (group instanceof ConcreteFeedItem) {
+                fireListTextLongClicked(idFeed, false, (long) ITEMS_WITHOUT_FOLDER.getValue());
+            } else {
+                fireListTextLongClicked(idFeed, true, ((FolderSubscribtionItem) group).idFolder);
             }
+            return true; //consume event
         });
 
 
@@ -337,14 +327,11 @@ public class SubscriptionExpandableListAdapter extends BaseExpandableListAdapter
                     contentDescriptionId = R.string.content_desc_expand;
                 }
         
-                viewHolder.binding.imgViewExpandableIndicator.setOnClickListener(new OnClickListener() {
-                    @Override
-                    public void onClick(View v) {
-                        if(isExpanded)
-                            ((ExpandableListView)listView).collapseGroup(groupPosition);
-                        else
-                            ((ExpandableListView)listView).expandGroup(groupPosition);
-                    }
+                viewHolder.binding.imgViewExpandableIndicator.setOnClickListener(v -> {
+                    if(isExpanded)
+                        ((ExpandableListView)listView).collapseGroup(groupPosition);
+                    else
+                        ((ExpandableListView)listView).expandGroup(groupPosition);
                 });
             }
         }
@@ -448,7 +435,7 @@ public class SubscriptionExpandableListAdapter extends BaseExpandableListAdapter
                 }
             }
 
-            notifyCountDataSetChanged(unreadCountFoldersTemp, unreadCountFeedsTemp, urlsToFavIconsTemp, starredCountFeedsTemp);
+            notifyCountDataSetChanged(unreadCountFoldersTemp, unreadCountFeedsTemp, starredCountFeedsTemp);
             super.onPostExecute(aVoid);
         }
     }
@@ -527,7 +514,7 @@ public class SubscriptionExpandableListAdapter extends BaseExpandableListAdapter
         for(int groupPosition = 0; groupPosition < mCategoriesArrayListAsync.size(); groupPosition++) {
             //int parent_id = (int)getGroupId(groupPosition);
             int parent_id = (int) mCategoriesArrayListAsync.get(groupPosition).id_database;
-            mItemsArrayListAsync.append(parent_id, new ArrayList<ConcreteFeedItem>());
+            mItemsArrayListAsync.append(parent_id, new ArrayList<>());
 
             List<Feed> feedItemList = null;
 
@@ -557,7 +544,7 @@ public class SubscriptionExpandableListAdapter extends BaseExpandableListAdapter
 
 
     @SuppressLint("NewApi") // wrongly reports setSelectionFromTop is only available in lollipop
-    public void notifyCountDataSetChanged(SparseArray<String> unreadCountFolders, SparseArray<String> unreadCountFeeds, SparseArray<String> urlsToFavIcons, SparseArray<String> starredCountFeeds) {
+    public void notifyCountDataSetChanged(SparseArray<String> unreadCountFolders, SparseArray<String> unreadCountFeeds, SparseArray<String> starredCountFeeds) {
         this.unreadCountFolders = unreadCountFolders;
         this.unreadCountFeeds = unreadCountFeeds;
         this.starredCountFeeds = starredCountFeeds;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/LoginDialogActivity.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/LoginDialogActivity.java
index da8feb32..e12fbabe 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/LoginDialogActivity.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/LoginDialogActivity.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -63,6 +63,7 @@ import com.nextcloud.android.sso.ui.UiExceptionManager;
 
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.util.Objects;
 
 import javax.inject.Inject;
 
@@ -79,6 +80,7 @@ import io.reactivex.disposables.Disposable;
 import io.reactivex.schedulers.Schedulers;
 
 import static de.luhmer.owncloudnewsreader.Constants.MIN_NEXTCLOUD_FILES_APP_VERSION_CODE;
+import static java.util.Objects.requireNonNull;
 
 /**
  * Activity which displays a login screen to the user, offering registration as
@@ -141,15 +143,9 @@ public class LoginDialogActivity extends AppCompatActivity {
         binding.edtOwncloudRootPath.setText(mOc_root_path);
 
         binding.cbAllowAllSSLCertificates.setChecked(mCbDisableHostnameVerification);
-        binding.cbAllowAllSSLCertificates.setOnCheckedChangeListener(new OnCheckedChangeListener() {
-            @SuppressLint("ApplySharedPref")
-            @Override
-            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
-                mPrefs.edit()
-                        .putBoolean(SettingsActivity.CB_DISABLE_HOSTNAME_VERIFICATION_STRING, isChecked)
-                        .commit();
-            }
-        });
+        binding.cbAllowAllSSLCertificates.setOnCheckedChangeListener((buttonView, isChecked) -> mPrefs.edit()
+                .putBoolean(SettingsActivity.CB_DISABLE_HOSTNAME_VERIFICATION_STRING, isChecked)
+                .commit());
 	}
 
     @Override
@@ -200,7 +196,7 @@ public class LoginDialogActivity extends AppCompatActivity {
         binding.oldLoginWrapper.setVisibility(View.VISIBLE);
     }
 
-	private TextWatcher PasswordTextChangedListener = new TextWatcher() {
+	private final TextWatcher PasswordTextChangedListener = new TextWatcher() {
 		@Override
 		public void beforeTextChanged(CharSequence s, int start, int count, int after) {
 
@@ -219,7 +215,7 @@ public class LoginDialogActivity extends AppCompatActivity {
 		}
 	};
 
-	private View.OnClickListener ImgViewShowPasswordListener = new View.OnClickListener() {
+	private final View.OnClickListener ImgViewShowPasswordListener = new View.OnClickListener() {
         @Override
         public void onClick(View v) {
             mPasswordVisible = !mPasswordVisible;
@@ -274,21 +270,22 @@ public class LoginDialogActivity extends AppCompatActivity {
 	 * If there are form errors (invalid email, missing fields, etc.), the
 	 * errors are presented and no actual login attempt is made.
 	 */
-	public void attemptLogin() {
+	@SuppressLint({"SetTextI18n"})
+    public void attemptLogin() {
 		// Reset errors.
 		binding.username.setError(null);
 		binding.password.setError(null);
 		binding.edtOwncloudRootPath.setError(null);
 
 		// Append "https://" is url doesn't contain it already
-        mOc_root_path = binding.edtOwncloudRootPath.getText().toString().trim();
+        mOc_root_path = requireNonNull(binding.edtOwncloudRootPath.getText()).toString().trim();
         if(!mOc_root_path.startsWith("http")) {
             binding.edtOwncloudRootPath.setText("https://" + mOc_root_path);
         }
 
 		// Store values at the time of the login attempt.
-		mUsername = binding.username.getText().toString().trim();
-		mPassword = binding.password.getText().toString();
+		mUsername = requireNonNull(binding.username.getText()).toString().trim();
+		mPassword = requireNonNull(binding.password.getText()).toString();
 		mOc_root_path = binding.edtOwncloudRootPath.getText().toString().trim();
 
 		boolean cancel = false;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewFeedActivity.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewFeedActivity.java
index 7f35bd06..2b9d4848 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewFeedActivity.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewFeedActivity.java
@@ -48,6 +48,7 @@ import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 import javax.inject.Inject;
 
@@ -65,6 +66,8 @@ import retrofit2.Call;
 import retrofit2.Callback;
 import retrofit2.Response;
 
+import static java.util.Objects.requireNonNull;
+
 public class NewFeedActivity extends AppCompatActivity {
 
     private static final String TAG = NewFeedActivity.class.getCanonicalName();
@@ -94,10 +97,8 @@ public class NewFeedActivity extends AppCompatActivity {
         binding.btnImportOpml.setOnClickListener((v) -> importOpml());
         binding.btnExportOpml.setOnClickListener((v) -> exportOpml());
 
-        if (binding.toolbarLayout.toolbar != null) {
-            setSupportActionBar(binding.toolbarLayout.toolbar);
-            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-        }
+        setSupportActionBar(binding.toolbarLayout.toolbar);
+        requireNonNull(getSupportActionBar()).setDisplayHomeAsUpEnabled(true);
 
         DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(this);
 
@@ -124,7 +125,7 @@ public class NewFeedActivity extends AppCompatActivity {
                 url = intent.getStringExtra(Intent.EXTRA_TEXT);
             }
 
-            if(url.endsWith(".opml")) {
+            if(url != null && url.endsWith(".opml")) {
                 AsyncTaskHelper.StartAsyncTask(new ImportOpmlSubscriptionsTask(url, NewFeedActivity.this));
             }
 
@@ -229,7 +230,7 @@ public class NewFeedActivity extends AppCompatActivity {
         private final String mUrlToFile;
         private HashMap<String, String> extractedUrls;
         private ProgressDialog pd;
-        private Context mContext;
+        private final Context mContext;
 
         ImportOpmlSubscriptionsTask(String urlToFile, Context context) {
             this.mUrlToFile = urlToFile;
@@ -318,16 +319,16 @@ public class NewFeedActivity extends AppCompatActivity {
 
         @Override
         protected void onProgressUpdate(List<String>... values) {
-            String text = "This might take a few minutes.. please wait:\n";
+            StringBuilder text = new StringBuilder("This might take a few minutes.. please wait:\n");
 
             List<String> log = values[0];
             for (String line : log) {
-                text += "\n" + line;
+                text.append("\n").append(line);
             }
 
             pd.setMax(extractedUrls.size());
             pd.setProgress(log.size());
-            pd.setMessage(text);
+            pd.setMessage(text.toString());
 
             super.onProgressUpdate(values);
         }
@@ -390,7 +391,7 @@ public class NewFeedActivity extends AppCompatActivity {
 
             mApi.getNewsAPI().createFeed(urlToFeed, folder.getId()).enqueue(new Callback<List<Feed>>() {
                 @Override
-                public void onResponse(Call<List<Feed>> call, final Response<List<Feed>> response) {
+                public void onResponse(@NonNull Call<List<Feed>> call, @NonNull final Response<List<Feed>> response) {
                     runOnUiThread(() -> {
                         showProgress(false);
 
@@ -423,7 +424,7 @@ public class NewFeedActivity extends AppCompatActivity {
                 }
 
                 @Override
-                public void onFailure(Call<List<Feed>> call, final Throwable t) {
+                public void onFailure(@NonNull Call<List<Feed>> call, @NonNull final Throwable t) {
                     runOnUiThread(() -> {
                         showProgress(false);
 
@@ -480,14 +481,12 @@ public class NewFeedActivity extends AppCompatActivity {
 
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            // Respond to the action bar's Up/Home button
-            case android.R.id.home:
-                //NavUtils.navigateUpFromSameTask(this);
-                finish();
-                return true;
-            default:
-                    Log.v(TAG, "Unknown option selected..");
+        // Respond to the action bar's Up/Home button
+        if (item.getItemId() == android.R.id.home) {//NavUtils.navigateUpFromSameTask(this);
+            finish();
+            return true;
+        } else {
+            Log.v(TAG, "Unknown option selected..");
         }
         return super.onOptionsItemSelected(item);
     }
@@ -498,7 +497,7 @@ public class NewFeedActivity extends AppCompatActivity {
     @NonNull public static String convertStreamToString(InputStream is) throws Exception {
         BufferedReader reader = new BufferedReader(new InputStreamReader(is));
         StringBuilder sb = new StringBuilder();
-        String line = null;
+        String line;
         while ((line = reader.readLine()) != null) {
             sb.append(line).append("\n");
         }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailActivity.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailActivity.java
index 801c7612..5785f081 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailActivity.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailActivity.java
@@ -1,5 +1,5 @@
-/**
- * Android ownCloud News
+/*
+* Android ownCloud News
  *
  * @author David Luhmer
  * @copyright 2013 David Luhmer david-dev@live.de
@@ -38,6 +38,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.webkit.WebView;
 
+import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentPagerAdapter;
@@ -47,6 +48,7 @@ import androidx.viewpager.widget.ViewPager;
 
 import java.lang.ref.WeakReference;
 import java.util.HashSet;
+import java.util.Objects;
 import java.util.Set;
 
 import javax.inject.Inject;
@@ -61,6 +63,8 @@ import de.luhmer.owncloudnewsreader.model.TTSItem;
 import de.luhmer.owncloudnewsreader.view.PodcastSlidingUpPanelLayout;
 import de.luhmer.owncloudnewsreader.widget.WidgetProvider;
 
+import static java.util.Objects.requireNonNull;
+
 
 public class NewsDetailActivity extends PodcastFragmentActivity {
 
@@ -141,9 +145,7 @@ public class NewsDetailActivity extends PodcastFragmentActivity {
 		}
 
 
-		if (binding.toolbarLayout.toolbar != null) {
-			setSupportActionBar(binding.toolbarLayout.toolbar);
-		}
+		setSupportActionBar(binding.toolbarLayout.toolbar);
 		/*
 		if (bottomAppBar != null) {
 			setSupportActionBar(bottomAppBar);
@@ -159,10 +161,10 @@ public class NewsDetailActivity extends PodcastFragmentActivity {
 			item_id = intent.getExtras().getInt(NewsReaderListActivity.ITEM_ID);
 		}
 		if (intent.hasExtra(NewsReaderListActivity.TITLE)) {
-			getSupportActionBar().setTitle(intent.getExtras().getString(NewsReaderListActivity.TITLE));
+			requireNonNull(getSupportActionBar()).setTitle(intent.getExtras().getString(NewsReaderListActivity.TITLE));
 		}
 
-		getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+		requireNonNull(getSupportActionBar()).setDisplayHomeAsUpEnabled(true);
 
 		rssItems = dbConn.getAllRssItems();
 
@@ -289,7 +291,7 @@ public class NewsDetailActivity extends PodcastFragmentActivity {
 		rssItems.close();
 	}
 
-    private ViewPager.OnPageChangeListener onPageChangeListener = new ViewPager.OnPageChangeListener() {
+    private final ViewPager.OnPageChangeListener onPageChangeListener = new ViewPager.OnPageChangeListener() {
 
         @Override
         public void onPageSelected(int pos) {
@@ -348,9 +350,9 @@ public class NewsDetailActivity extends PodcastFragmentActivity {
 
 		if (rssItems.get(position).getFeed() != null) {
 			// Try getting the feed title and use it for the action bar title
-			getSupportActionBar().setTitle(rssItems.get(position).getFeed().getFeedTitle());
+			requireNonNull(getSupportActionBar()).setTitle(rssItems.get(position).getFeed().getFeedTitle());
 		} else {
-			getSupportActionBar().setTitle(rssItems.get(position).getTitle());
+			requireNonNull(getSupportActionBar()).setTitle(rssItems.get(position).getTitle());
 		}
 
 		RssItem rssItem = rssItems.get(position);
@@ -480,38 +482,24 @@ public class NewsDetailActivity extends PodcastFragmentActivity {
 	public boolean onOptionsItemSelected(MenuItem item) {
 		RssItem rssItem = rssItems.get(currentPosition);
 
-		switch (item.getItemId()) {
-			case android.R.id.home:
-				onBackPressed();
-				return true;
-
-			case R.id.action_read:
-				this.markRead(currentPosition);
-				break;
-
-			case R.id.action_starred:
-				toggleRssItemStarredState();
-				break;
-
-			case R.id.action_openInBrowser:
-				this.openInBrowser(currentPosition);
-				break;
-
-			case R.id.action_playPodcast:
-				openPodcast(rssItem);
-				break;
-
-			case R.id.action_tts:
-				this.startTTS(currentPosition);
-				break;
-
-			case R.id.action_ShareItem:
-				this.share(currentPosition);
-				break;
-
-			case R.id.action_incognito_mode:
-				toggleIncognitoMode();
-				break;
+		final int itemId = item.getItemId();
+		if (itemId == android.R.id.home) {
+			onBackPressed();
+			return true;
+		} else if (itemId == R.id.action_read) {
+			this.markRead(currentPosition);
+		} else if (itemId == R.id.action_starred) {
+			toggleRssItemStarredState();
+		} else if (itemId == R.id.action_openInBrowser) {
+			this.openInBrowser(currentPosition);
+		} else if (itemId == R.id.action_playPodcast) {
+			openPodcast(rssItem);
+		} else if (itemId == R.id.action_tts) {
+			this.startTTS(currentPosition);
+		} else if (itemId == R.id.action_ShareItem) {
+			this.share(currentPosition);
+		} else if (itemId == R.id.action_incognito_mode) {
+			toggleIncognitoMode();
 		}
 
 		return super.onOptionsItemSelected(item);
@@ -527,7 +515,7 @@ public class NewsDetailActivity extends PodcastFragmentActivity {
 		NewsDetailFragment newsDetailFragment = getNewsDetailFragmentAtPosition(currentPosition);
 		String link = "about:blank";
 
-		if (newsDetailFragment != null && newsDetailFragment.binding.webview != null) {
+		if (newsDetailFragment != null) {
 			link = newsDetailFragment.binding.webview.getUrl();
 		}
 
@@ -536,7 +524,7 @@ public class NewsDetailActivity extends PodcastFragmentActivity {
 		}
 
 		if (link.length() > 0) {
-			newsDetailFragment.loadURL(link);
+			requireNonNull(newsDetailFragment).loadURL(link);
 		}
 	}
 
@@ -610,7 +598,7 @@ public class NewsDetailActivity extends PodcastFragmentActivity {
 		Intent browserIntent = new Intent("android.intent.action.VIEW", Uri.parse("http://"));
 		ResolveInfo resolveInfo = getPackageManager().resolveActivity(browserIntent, PackageManager.MATCH_DEFAULT_ONLY);
 
-		Log.v(TAG, "Default Browser is: " + resolveInfo.loadLabel(getPackageManager()).toString());
+		Log.v(TAG, "Default Browser is: " + requireNonNull(resolveInfo).loadLabel(getPackageManager()).toString());
 		return (resolveInfo.loadLabel(getPackageManager()).toString().contains("Chrome"));
 	}
 
@@ -710,6 +698,7 @@ public class NewsDetailActivity extends PodcastFragmentActivity {
 			}
 		}
 
+		@NonNull
 		@Override
 		public Fragment getItem(int position) {
 			NewsDetailFragment fragment = null;
@@ -730,7 +719,7 @@ public class NewsDetailActivity extends PodcastFragmentActivity {
 		}
 
 		@Override
-		public void destroyItem(ViewGroup container, int position, Object object) {
+		public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
 			items.remove(position);
 
 			super.destroyItem(container, position, object);
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailFragment.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailFragment.java
index 3e8cc957..755349ea 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailFragment.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailFragment.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -39,11 +39,14 @@ import android.webkit.WebSettings;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.appcompat.app.AppCompatActivity;
 import androidx.browser.customtabs.CustomTabsIntent;
 import androidx.core.content.ContextCompat;
 import androidx.fragment.app.DialogFragment;
 import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentTransaction;
 
 import org.jsoup.Jsoup;
@@ -92,7 +95,7 @@ public class NewsDetailFragment extends Fragment implements RssItemToHtmlTask.Li
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        ((NewsReaderApplication) getActivity().getApplication()).getAppComponent().injectFragment(this);
+        ((NewsReaderApplication) requireActivity().getApplication()).getAppComponent().injectFragment(this);
 
         // Retain this fragment across configuration changes.
         setRetainInstance(true);
@@ -115,24 +118,18 @@ public class NewsDetailFragment extends Fragment implements RssItemToHtmlTask.Li
     @Override
     public void onDestroy() {
         super.onDestroy();
-        if(binding.webview != null) {
-            binding.webview.destroy();
-        }
+        binding.webview.destroy();
     }
 
     public void pauseCurrentPage() {
-        if(binding.webview != null) {
-            binding.webview.onPause();
-            binding.webview.pauseTimers();
-        }
+        binding.webview.onPause();
+        binding.webview.pauseTimers();
     }
 
 
     public void resumeCurrentPage() {
-        if(binding.webview != null) {
-            binding.webview.onResume();
-            binding.webview.resumeTimers();
-        }
+        binding.webview.onResume();
+        binding.webview.resumeTimers();
     }
 
     /**
@@ -159,10 +156,10 @@ public class NewsDetailFragment extends Fragment implements RssItemToHtmlTask.Li
     }
 
     @Override
-	public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+	public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         binding = FragmentNewsDetailBinding.inflate(inflater, container, false);
 
-		section_number = (Integer) getArguments().get(ARG_SECTION_NUMBER);
+		section_number = (Integer) requireArguments().get(ARG_SECTION_NUMBER);
 
         // Do not reload webview if retained
         if(savedInstanceState == null) {
@@ -181,14 +178,14 @@ public class NewsDetailFragment extends Fragment implements RssItemToHtmlTask.Li
 	}
 
 	protected void syncIncognitoState() {
-        NewsDetailActivity ndActivity = ((NewsDetailActivity)getActivity());
+        NewsDetailActivity ndActivity = ((NewsDetailActivity) requireActivity());
         boolean isIncognito = ndActivity.isIncognitoEnabled();
         binding.webview.getSettings().setBlockNetworkLoads(isIncognito);
         // binding.webview.getSettings().setBlockNetworkImage(isIncognito);
     }
 
 	@Override
-    public void onSaveInstanceState(Bundle outState) {
+    public void onSaveInstanceState(@NonNull Bundle outState) {
         binding.webview.saveState(outState);
     }
 
@@ -261,8 +258,6 @@ public class NewsDetailFragment extends Fragment implements RssItemToHtmlTask.Li
 
     /**
      * This function has no effect on devices with api level < HONEYCOMB
-     * @param htmlPage
-     * @param webView
      */
     private void setSoftwareRenderModeForWebView(String htmlPage, WebView webView) {
         if (htmlPage.contains(".gif")) {
@@ -307,7 +302,7 @@ public class NewsDetailFragment extends Fragment implements RssItemToHtmlTask.Li
 
         binding.webview.setWebViewClient(new WebViewClient() {
 
-            private Map<String, Boolean> loadedUrls = new HashMap<>();
+            private final Map<String, Boolean> loadedUrls = new HashMap<>();
 
             @Override
             public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
@@ -385,13 +380,14 @@ public class NewsDetailFragment extends Fragment implements RssItemToHtmlTask.Li
             binding.tvOfflineVersion.setVisibility(View.GONE);
             switch (selectedBrowser) {
                 case 0: // Custom Tabs
+                    final FragmentActivity activity = requireActivity();
                     CustomTabsIntent.Builder builder = new CustomTabsIntent.Builder()
-                            .setToolbarColor(ContextCompat.getColor(getActivity(), R.color.colorPrimary))
+                            .setToolbarColor(ContextCompat.getColor(activity, R.color.colorPrimary))
                             .setShowTitle(true)
-                            .setStartAnimations(getActivity(), R.anim.slide_in_right, R.anim.slide_out_left)
-                            .setExitAnimations(getActivity(), R.anim.slide_in_left, R.anim.slide_out_right)
+                            .setStartAnimations(activity, R.anim.slide_in_right, R.anim.slide_out_left)
+                            .setExitAnimations(activity, R.anim.slide_in_left, R.anim.slide_out_right)
                             .addDefaultShareMenuItem();
-                    builder.build().launchUrl(getActivity(), Uri.parse(url));
+                    builder.build().launchUrl(activity, Uri.parse(url));
                     break;
                 case 1: // External Browser
                     Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
@@ -407,7 +403,7 @@ public class NewsDetailFragment extends Fragment implements RssItemToHtmlTask.Li
     }
 
 
-    public void onCreateContextMenu(ContextMenu menu, View view, ContextMenu.ContextMenuInfo menuInfo) {
+    public void onCreateContextMenu(@NonNull ContextMenu menu, @NonNull View view, ContextMenu.ContextMenuInfo menuInfo) {
 	    if (!(view instanceof WebView)) {
             Log.w(TAG, "onCreateContextMenu - no webview reference found");
             return;
@@ -421,7 +417,7 @@ public class NewsDetailFragment extends Fragment implements RssItemToHtmlTask.Li
 
         int type = result.getType();
         Document htmlDoc = Jsoup.parse(html);
-        FragmentTransaction ft = getFragmentManager().beginTransaction();
+        FragmentTransaction ft = requireFragmentManager().beginTransaction();
         String text;
         DialogFragment newFragment;
 
@@ -505,6 +501,7 @@ public class NewsDetailFragment extends Fragment implements RssItemToHtmlTask.Li
      * @return true when the current page on the webview's history stack is
      * the original rss item page
      */
+    @SuppressWarnings("BooleanMethodIsAlwaysInverted")
     private boolean isCurrentPageRssItem() {
         if(binding.webview.copyBackForwardList().getCurrentItem() != null) {
             String currentPageUrl = binding.webview.copyBackForwardList().getCurrentItem().getOriginalUrl();
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailImageDialogFragment.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailImageDialogFragment.java
index 36c61463..a2c22a76 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailImageDialogFragment.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsDetailImageDialogFragment.java
@@ -96,11 +96,12 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        mDialogIcon = getArguments().getInt("titleIcon");
-        mDialogTitle = getArguments().getString("title");
-        mDialogText = getArguments().getString("text");
-        mImageUrl = (URL) getArguments().getSerializable("imageUrl");
-        mDialogType = (TYPE) getArguments().getSerializable("dialogType");
+        final Bundle args = requireArguments();
+        mDialogIcon = args.getInt("titleIcon");
+        mDialogTitle = args.getString("title");
+        mDialogText = args.getString("text");
+        mImageUrl = (URL) args.getSerializable("imageUrl");
+        mDialogType = (TYPE) args.getSerializable("dialogType");
 
         mMenuItems = new LinkedHashMap<>();
 
@@ -120,24 +121,9 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
                             changeDownloadDir();
                         }
                     });
-                    mMenuItems.put(getString(R.string.action_img_open), new MenuAction() {
-                        @Override
-                        public void execute() {
-                            openLinkInBrowser(mImageUrl);
-                        }
-                    });
-                    mMenuItems.put(getString(R.string.action_img_sharelink), new MenuAction() {
-                        @Override
-                        public void execute() {
-                            shareImage();
-                        }
-                    });
-                    mMenuItems.put(getString(R.string.action_img_copylink), new MenuAction() {
-                        @Override
-                        public void execute() {
-                            copyToClipboard(mDialogTitle, mImageUrl.toString());
-                        }
-                    });
+                    mMenuItems.put(getString(R.string.action_img_open), () -> openLinkInBrowser(mImageUrl));
+                    mMenuItems.put(getString(R.string.action_img_sharelink), this::shareImage);
+                    mMenuItems.put(getString(R.string.action_img_copylink), () -> copyToClipboard(mDialogTitle, mImageUrl.toString()));
                 } else if (mImageUrl.toString().startsWith("file:///")) {
                     mMenuItems.put(getString(R.string.action_img_download), new MenuActionLongClick() {
                         @Override
@@ -157,35 +143,20 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
                 }
                 break;
             case URL:
-                mMenuItems.put(getString(R.string.action_link_open), new MenuAction() {
-                    @Override
-                    public void execute() {
-                        try {
-                            openLinkInBrowser(new URL(mDialogText));
-                        } catch (MalformedURLException e) {
-                            Toast.makeText(getActivity(), getString(R.string.error_invalid_url), Toast.LENGTH_SHORT).show();
-                            e.printStackTrace();
-                        }
-                    }
-                });
-                mMenuItems.put(getString(R.string.action_link_share), new MenuAction() {
-                    @Override
-                    public void execute() {
-                        shareLink();
-                    }
-                });
-                mMenuItems.put(getString(R.string.action_link_copy), new MenuAction() {
-                    @Override
-                    public void execute() {
-                        copyToClipboard(mDialogTitle, mDialogText);
+                mMenuItems.put(getString(R.string.action_link_open), () -> {
+                    try {
+                        openLinkInBrowser(new URL(mDialogText));
+                    } catch (MalformedURLException e) {
+                        Toast.makeText(getActivity(), getString(R.string.error_invalid_url), Toast.LENGTH_SHORT).show();
+                        e.printStackTrace();
                     }
                 });
+                mMenuItems.put(getString(R.string.action_link_share), this::shareLink);
+                mMenuItems.put(getString(R.string.action_link_copy), () -> copyToClipboard(mDialogTitle, mDialogText));
                 break;
         }
 
-        int style = DialogFragment.STYLE_NO_TITLE;
-        int theme = R.style.FloatingDialog;
-        setStyle(style, theme);
+        setStyle(DialogFragment.STYLE_NO_TITLE, R.style.FloatingDialog);
     }
 
     @Override
@@ -195,9 +166,10 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
     }
 
     private void showDownloadShowcase() {
-        if(mMenuItems.containsKey(getActivity().getString(R.string.action_img_download))) {
+        final Context context = requireContext();
+        if(mMenuItems.containsKey(context.getString(R.string.action_img_download))) {
             List<String> menuItemsList = new ArrayList<>(mMenuItems.keySet());
-            int position = menuItemsList.indexOf(getActivity().getString(R.string.action_img_download));
+            int position = menuItemsList.indexOf(context.getString(R.string.action_img_download));
             Log.v(TAG, "Position of Download Menu: " + position);
             /*
             // Bug in the Library.. ShowcaseView is rendered behind the DialogFragment //TODO check https://github.com/deano2390/MaterialShowcaseView/issues/51 for updates
@@ -233,7 +205,7 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
             }
         }
 
-        ListView mListView = (ListView) v.findViewById(R.id.ic_menu_item_list);
+        ListView mListView = v.findViewById(R.id.ic_menu_item_list);
         List<String> menuItemsList = new ArrayList<>(mMenuItems.keySet());
 
         final ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(
@@ -278,7 +250,7 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
 
 
     private void copyToClipboard(String label, String text) {
-        ClipboardManager clipboard = (ClipboardManager) getActivity().getSystemService(Activity.CLIPBOARD_SERVICE);
+        ClipboardManager clipboard = (ClipboardManager) requireContext().getSystemService(Activity.CLIPBOARD_SERVICE);
         ClipData clip = ClipData.newPlainText(label, text);
         clipboard.setPrimaryClip(clip);
         Toast.makeText(getActivity(), getString(R.string.toast_copied_to_clipboard), Toast.LENGTH_SHORT).show();
@@ -312,11 +284,11 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
     }
 
     private void downloadImage(URL url) {
-        Toast.makeText(getActivity().getApplicationContext(), getString(R.string.toast_img_download_wait), Toast.LENGTH_SHORT).show();
+        Toast.makeText(requireContext().getApplicationContext(), getString(R.string.toast_img_download_wait), Toast.LENGTH_SHORT).show();
 
         if(isExternalStorageWritable()) {
             String filename = url.getFile().substring(url.getFile().lastIndexOf('/') + 1, url.getFile().length());
-            downloadManager = (DownloadManager) getActivity().getSystemService(Context.DOWNLOAD_SERVICE);
+            downloadManager = (DownloadManager) requireContext().getSystemService(Context.DOWNLOAD_SERVICE);
             DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url.toString()));
             request.setDestinationUri(getDownloadDir(filename));
             request.setTitle(getString(R.string.app_name) + " - " + getString(R.string.action_img_download));
@@ -327,9 +299,9 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
             //request.setVisibleInDownloadsUi(false);
             //request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_HIDDEN);
             downloadID = downloadManager.enqueue(request);
-            getDialog().hide();
+            requireDialog().hide();
         } else {
-            Toast.makeText(getActivity().getApplicationContext(), getString(R.string.toast_img_notwriteable), Toast.LENGTH_LONG).show();
+            Toast.makeText(requireContext().getApplicationContext(), getString(R.string.toast_img_notwriteable), Toast.LENGTH_LONG).show();
             dismiss();
         }
     }
@@ -343,24 +315,24 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
             try {
                 NewsFileUtils.copyFile(new FileInputStream(path), new FileOutputStream(dstPath));
             } catch (IOException e) {
-                Toast.makeText(getActivity().getApplicationContext(), e.getMessage(), Toast.LENGTH_LONG).show();
+                Toast.makeText(requireContext().getApplicationContext(), e.getMessage(), Toast.LENGTH_LONG).show();
             }
-            NextcloudNotificationManager.showNotificationSaveSingleCachedImageService(getActivity().getApplicationContext(), CHANNEL_ID, dstPath);
-            getDialog().hide();
+            NextcloudNotificationManager.showNotificationSaveSingleCachedImageService(requireContext().getApplicationContext(), CHANNEL_ID, dstPath);
+            requireDialog().hide();
         } else {
-            Toast.makeText(getActivity().getApplicationContext(), getString(R.string.toast_img_notwriteable), Toast.LENGTH_LONG).show();
+            Toast.makeText(requireContext().getApplicationContext(), getString(R.string.toast_img_notwriteable), Toast.LENGTH_LONG).show();
             dismiss();
         }
     }
 
     public boolean haveStoragePermission() {
         if (Build.VERSION.SDK_INT >= 23) {
-            if (checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE) == PermissionChecker.PERMISSION_GRANTED) {
+            if (checkSelfPermission(requireContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE) == PermissionChecker.PERMISSION_GRANTED) {
                 Log.v("Permission error","You have permission");
                 return true;
             } else {
                 Log.e("Permission error","Asking for permission");
-                ActivityCompat.requestPermissions(getActivity(), new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
+                ActivityCompat.requestPermissions(requireActivity(), new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
                 return false;
             }
         }
@@ -374,7 +346,7 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
     private void changeDownloadDir() {
         final Intent chooserIntent = new Intent(getActivity(), DirectoryChooserActivity.class);
         final DirectoryChooserConfig config = DirectoryChooserConfig.builder()
-                .initialDirectory(getActivity().getPreferences(Context.MODE_PRIVATE).getString("manualImageDownloadLocation", ""))
+                .initialDirectory(requireActivity().getPreferences(Context.MODE_PRIVATE).getString("manualImageDownloadLocation", ""))
                 .newDirectoryName("new folder")
                 .allowNewDirectoryNameModification(true)
                 .allowReadOnlyDirectory(false)
@@ -388,14 +360,14 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
         if(path.equals("")) {
             path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).toString();
         }
-        SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
+        SharedPreferences sharedPref = requireActivity().getPreferences(Context.MODE_PRIVATE);
         SharedPreferences.Editor editor = sharedPref.edit();
         editor.putString("manualImageDownloadLocation", path);
         editor.commit();
     }
 
     private Uri getDownloadDir(String filename) {
-        SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
+        SharedPreferences sharedPref = requireActivity().getPreferences(Context.MODE_PRIVATE);
         String dir = sharedPref.getString("manualImageDownloadLocation", "");
         if(dir.equals("")) { //sharedPref has never been set
             setNewDownloadDir(""); //set to default public download dir
@@ -419,7 +391,7 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
 
     private void unregisterImageDownloadReceiver() {
         if (downloadCompleteReceiver != null) {
-            getActivity().unregisterReceiver(downloadCompleteReceiver);
+            requireActivity().unregisterReceiver(downloadCompleteReceiver);
             downloadCompleteReceiver = null;
         }
     }
@@ -443,7 +415,7 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
 
                     switch (status) {
                         case DownloadManager.STATUS_SUCCESSFUL:
-                            Toast.makeText(getActivity().getApplicationContext(), getString(R.string.toast_img_saved), Toast.LENGTH_LONG).show();
+                            Toast.makeText(requireContext().getApplicationContext(), getString(R.string.toast_img_saved), Toast.LENGTH_LONG).show();
 
                             //String imagePath = downloadManager.getUriForDownloadedFile(refID).toString();
 
@@ -457,7 +429,7 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
                             }
                             break;
                         case DownloadManager.STATUS_FAILED:
-                            Toast.makeText(getActivity().getApplicationContext(), getString(R.string.error_download_failed) + ": " + reason, Toast.LENGTH_LONG).show();
+                            Toast.makeText(requireContext().getApplicationContext(), getString(R.string.error_download_failed) + ": " + reason, Toast.LENGTH_LONG).show();
                             if(isVisible()) {
                                 dismiss();
                             }
@@ -469,7 +441,7 @@ public class NewsDetailImageDialogFragment extends DialogFragment {
             }
         };
         IntentFilter intentFilter = new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE);
-        getActivity().registerReceiver(downloadCompleteReceiver, intentFilter);
+        requireActivity().registerReceiver(downloadCompleteReceiver, intentFilter);
     }
 
     public boolean isExternalStorageWritable() {
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderDetailFragment.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderDetailFragment.java
index 86859afb..f4fc236b 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderDetailFragment.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderDetailFragment.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -46,6 +46,7 @@ import android.view.animation.AnimationUtils;
 import android.widget.ImageView;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
 import androidx.core.content.ContextCompat;
 import androidx.core.view.GestureDetectorCompat;
 import androidx.fragment.app.Fragment;
@@ -58,6 +59,7 @@ import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
 
 import java.util.List;
+import java.util.Objects;
 
 import javax.inject.Inject;
 
@@ -81,6 +83,7 @@ import static de.luhmer.owncloudnewsreader.SettingsActivity.SP_SWIPE_LEFT_ACTION
 import static de.luhmer.owncloudnewsreader.SettingsActivity.SP_SWIPE_LEFT_ACTION_DEFAULT;
 import static de.luhmer.owncloudnewsreader.SettingsActivity.SP_SWIPE_RIGHT_ACTION;
 import static de.luhmer.owncloudnewsreader.SettingsActivity.SP_SWIPE_RIGHT_ACTION_DEFAULT;
+import static java.util.Objects.requireNonNull;
 
 /**
  * A fragment representing a single NewsReader detail screen. This fragment is
@@ -125,7 +128,7 @@ public class NewsReaderDetailFragment extends Fragment {
     }
 
     @Override
-    public void onAttach(Context context) {
+    public void onAttach(@NonNull Context context) {
         super.onAttach(context);
         this.mActivity = (PodcastFragmentActivity) context;
     }
@@ -138,7 +141,7 @@ public class NewsReaderDetailFragment extends Fragment {
 
     protected DisposableObserver<List<RssItem>> searchResultObserver = new DisposableObserver<List<RssItem>>() {
         @Override
-        public void onNext(List<RssItem> rssItems) {
+        public void onNext(@NonNull List<RssItem> rssItems) {
             loadRssItemsIntoView(rssItems);
         }
 
@@ -186,7 +189,7 @@ public class NewsReaderDetailFragment extends Fragment {
         this.idFeed = idFeed;
         this.idFolder = idFolder;
         this.titel = title;
-        mActivity.getSupportActionBar().setTitle(title);
+        requireNonNull(mActivity.getSupportActionBar()).setTitle(title);
 
         if (updateListView) {
             updateCurrentRssView();
@@ -200,7 +203,7 @@ public class NewsReaderDetailFragment extends Fragment {
         Log.v(TAG, "onResume called!");
 
         mMarkAsReadWhileScrollingEnabled = mPrefs.getBoolean(SettingsActivity.CB_MARK_AS_READ_WHILE_SCROLLING_STRING, false);
-        this.initFastDoneAll(this.getView());
+        this.initFastDoneAll(this.requireView());
 
         //When the fragment is instantiated by the xml file, onResume will be called twice
         if (onResumeCount >= 2) {
@@ -216,11 +219,7 @@ public class NewsReaderDetailFragment extends Fragment {
     protected void updateMenuItemsState() {
         NewsReaderListActivity nla = (NewsReaderListActivity) mActivity;
         if(nla != null && nla.getMenuItemDownloadMoreItems() != null) {
-            if (idFolder != null && idFolder == ALL_UNREAD_ITEMS.getValue()) {
-                nla.getMenuItemDownloadMoreItems().setEnabled(false);
-            } else {
-                nla.getMenuItemDownloadMoreItems().setEnabled(true);
-            }
+            nla.getMenuItemDownloadMoreItems().setEnabled(idFolder == null || idFolder != ALL_UNREAD_ITEMS.getValue());
         }
     }
 
@@ -243,7 +242,7 @@ public class NewsReaderDetailFragment extends Fragment {
                 binding.pbLoading.setVisibility(View.GONE);
 
                 if (layoutManagerSavedState != null) {
-                    binding.list.getLayoutManager().onRestoreInstanceState(layoutManagerSavedState);
+                    requireNonNull(binding.list.getLayoutManager()).onRestoreInstanceState(layoutManagerSavedState);
                     layoutManagerSavedState = null;
                 }
             });
@@ -278,7 +277,6 @@ public class NewsReaderDetailFragment extends Fragment {
     }
 
     public LinearLayoutManager getLayoutManager() {
-        if (binding.list == null) return null;
         return (LinearLayoutManager) binding.list.getLayoutManager();
     }
 
@@ -319,7 +317,7 @@ public class NewsReaderDetailFragment extends Fragment {
     }
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container,
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
         binding = FragmentNewsreaderDetailBinding.inflate(inflater, container, false);
 
@@ -346,7 +344,7 @@ public class NewsReaderDetailFragment extends Fragment {
 
         binding.list.addOnScrollListener(new RecyclerView.OnScrollListener() {
             @Override
-            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
+            public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
                 if (dy > 0) { //check for scroll down
                     if (mMarkAsReadWhileScrollingEnabled) {
                         //Log.v(TAG, "Scroll Delta y: " + dy);
@@ -357,16 +355,16 @@ public class NewsReaderDetailFragment extends Fragment {
         });
 
         itemTouchListener = new RecyclerView.OnItemTouchListener() {
-            GestureDetectorCompat detector = new GestureDetectorCompat(mActivity, new RecyclerViewOnGestureListener());
+            final GestureDetectorCompat detector = new GestureDetectorCompat(mActivity, new RecyclerViewOnGestureListener());
 
             @Override
-            public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
+            public boolean onInterceptTouchEvent(@NonNull RecyclerView rv, @NonNull MotionEvent e) {
                 detector.onTouchEvent(e);
                 return false;
             }
 
             @Override
-            public void onTouchEvent(RecyclerView rv, MotionEvent e) {
+            public void onTouchEvent(@NonNull RecyclerView rv, @NonNull MotionEvent e) {
             }
 
             @Override
@@ -431,10 +429,10 @@ public class NewsReaderDetailFragment extends Fragment {
     }
 
     @Override
-    public void onInflate(Context context, AttributeSet attrs, Bundle savedInstanceState) {
+    public void onInflate(@NonNull Context context, @NonNull AttributeSet attrs, Bundle savedInstanceState) {
         super.onInflate(context, attrs, savedInstanceState);
 
-        ((NewsReaderApplication) getActivity().getApplication()).getAppComponent().injectFragment(this);
+        ((NewsReaderApplication) requireActivity().getApplication()).getAppComponent().injectFragment(this);
 
         TypedArray styledAttributes = context.obtainStyledAttributes(attrs, new int[]{R.attr.colorAccent});
         updateSwipeDrawables(true);
@@ -460,7 +458,7 @@ public class NewsReaderDetailFragment extends Fragment {
         int leftId  = getLayoutId(leftAction);
         int rightId = getLayoutId(rightAction);
 
-        TypedArray styledAttributes = getContext().obtainStyledAttributes(new int[]{leftId, rightId});
+        TypedArray styledAttributes = requireContext().obtainStyledAttributes(new int[]{leftId, rightId});
         leftSwipeDrawable = styledAttributes.getDrawable(0);
         rightSwipeDrawable = styledAttributes.getDrawable(1);
         styledAttributes.recycle();
@@ -485,7 +483,7 @@ public class NewsReaderDetailFragment extends Fragment {
     }
 
     @Override
-    public void onSaveInstanceState(Bundle outState) {
+    public void onSaveInstanceState(@NonNull Bundle outState) {
         super.onSaveInstanceState(outState);
 
         outState.putParcelable(LAYOUT_MANAGER_STATE, getLayoutManager().onSaveInstanceState());
@@ -597,17 +595,17 @@ public class NewsReaderDetailFragment extends Fragment {
         }
 
         @Override
-        public float getSwipeThreshold(RecyclerView.ViewHolder viewHolder) {
+        public float getSwipeThreshold(@NonNull RecyclerView.ViewHolder viewHolder) {
             return 0.25f;
         }
 
         @Override
-        public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
+        public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
             return false;
         }
 
         @Override
-        public void onSwiped(final RecyclerView.ViewHolder viewHolder, final int direction) {
+        public void onSwiped(@NonNull final RecyclerView.ViewHolder viewHolder, final int direction) {
             final NewsListRecyclerAdapter adapter = (NewsListRecyclerAdapter) binding.list.getAdapter();
 
             String swipeAction;
@@ -637,7 +635,7 @@ public class NewsReaderDetailFragment extends Fragment {
         }
 
         @Override
-        public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
+        public void onChildDraw(@NonNull Canvas c, @NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
             super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
             // binding.swipeRefresh cancels swiping left/right when accidentally moving in the y direction;
             binding.swipeRefresh.setEnabled(!isCurrentlyActive);
@@ -673,8 +671,8 @@ public class NewsReaderDetailFragment extends Fragment {
      * A movement up is required to prevent accidentally marking articles as read.
      */
     private class FastMarkReadMotionListener implements View.OnTouchListener {
-        private View fabMarkAllAsRead;
-        private ImageView targetView;
+        private final View fabMarkAllAsRead;
+        private final ImageView targetView;
 
         private boolean markAsRead = false;
         private float originX,
@@ -684,7 +682,7 @@ public class NewsReaderDetailFragment extends Fragment {
 
         public FastMarkReadMotionListener(View fabMarkAllAsRead) {
             this.fabMarkAllAsRead = fabMarkAllAsRead;
-            this.targetView = (ImageView)fabMarkAllAsRead.findViewById(R.id.target_done_all);
+            this.targetView = fabMarkAllAsRead.findViewById(R.id.target_done_all);
         }
 
         @Override
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListActivity.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListActivity.java
index 826d520e..07c51c93 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListActivity.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListActivity.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -171,7 +171,7 @@ public class NewsReaderListActivity extends PodcastFragmentActivity implements
 	String sharedPreferencesFileName;
 
 
-	private View.OnClickListener mSnackbarListener = view -> {
+	private final View.OnClickListener mSnackbarListener = view -> {
 		//Toast.makeText(getActivity(), "button 1 pressed", 3000).show();
 		updateCurrentRssView();
 	};
@@ -219,9 +219,7 @@ public class NewsReaderListActivity extends PodcastFragmentActivity implements
 		initAccountManager();
 
 		binding.toolbarLayout.avatar.setVisibility(View.VISIBLE);
-		binding.toolbarLayout.avatar.setOnClickListener((v) -> {
-			startActivityForResult(new Intent(this, LoginDialogActivity.class), RESULT_LOGIN);
-		});
+		binding.toolbarLayout.avatar.setOnClickListener((v) -> startActivityForResult(new Intent(this, LoginDialogActivity.class), RESULT_LOGIN));
 
 		// Init config --> if nothing is configured start the login dialog.
 		if (!isUserLoggedIn()) {
@@ -780,63 +778,50 @@ public class NewsReaderListActivity extends PodcastFragmentActivity implements
 		if (drawerToggle != null && drawerToggle.onOptionsItemSelected(item))
 			return true;
 
-		switch (item.getItemId()) {
-
-			case android.R.id.home:
-				if (handlePodcastBackPressed())
-					return true;
-				break;
-
-			case R.id.menu_update:
-				startSync();
-				break;
-
-			case R.id.menu_StartImageCaching:
-				final DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(this);
-
-				long highestItemId = dbConn.getLowestRssItemIdUnread();
-
-
-				Intent data = new Intent();
-				data.putExtra(DownloadImagesService.LAST_ITEM_ID, highestItemId);
-				data.putExtra(DownloadImagesService.DOWNLOAD_MODE_STRING, DownloadImagesService.DownloadMode.PICTURES_ONLY);
-				DownloadImagesService.enqueueWork(this, data);
-
-				break;
-
-			case R.id.menu_CreateDatabaseDump:
-				DatabaseUtils.CopyDatabaseToSdCard(this);
-
-				new AlertDialog.Builder(this)
-						.setMessage("Created dump at: " + DatabaseUtils.GetPath(this))
-						.setNeutralButton(getString(android.R.string.ok), null)
-						.show();
-				break;
-
-			case R.id.menu_markAllAsRead:
-				NewsReaderDetailFragment ndf = getNewsReaderDetailFragment();
-				if(ndf != null) {
-					DatabaseConnectionOrm dbConn2 = new DatabaseConnectionOrm(this);
-					dbConn2.markAllItemsAsReadForCurrentView();
-
-					reloadCountNumbersOfSlidingPaneAdapter();
-					ndf.refreshCurrentRssView();
-				}
+		int itemId = item.getItemId();
+		if (itemId == android.R.id.home) {
+			if (handlePodcastBackPressed())
 				return true;
-
-			case R.id.menu_downloadMoreItems:
-				DownloadMoreItems();
-				return true;
-
-			case R.id.menu_search:
-				mSearchView.setIconified(false);
-				mSearchView.setFocusable(true);
-				mSearchView.requestFocusFromTouch();
-                return true;
-
-            case R.id.menu_download_web_archive:
-                checkAndStartDownloadWebPagesForOfflineReadingPermission();
-                return true;
+		} else if (itemId == R.id.menu_update) {
+			startSync();
+		} else if (itemId == R.id.menu_StartImageCaching) {
+			final DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(this);
+
+			long highestItemId = dbConn.getLowestRssItemIdUnread();
+
+
+			Intent data = new Intent();
+			data.putExtra(DownloadImagesService.LAST_ITEM_ID, highestItemId);
+			data.putExtra(DownloadImagesService.DOWNLOAD_MODE_STRING, DownloadImagesService.DownloadMode.PICTURES_ONLY);
+			DownloadImagesService.enqueueWork(this, data);
+		} else if (itemId == R.id.menu_CreateDatabaseDump) {
+			DatabaseUtils.CopyDatabaseToSdCard(this);
+
+			new AlertDialog.Builder(this)
+					.setMessage("Created dump at: " + DatabaseUtils.GetPath(this))
+					.setNeutralButton(getString(android.R.string.ok), null)
+					.show();
+		} else if (itemId == R.id.menu_markAllAsRead) {
+			NewsReaderDetailFragment ndf = getNewsReaderDetailFragment();
+			if (ndf != null) {
+				DatabaseConnectionOrm dbConn2 = new DatabaseConnectionOrm(this);
+				dbConn2.markAllItemsAsReadForCurrentView();
+
+				reloadCountNumbersOfSlidingPaneAdapter();
+				ndf.refreshCurrentRssView();
+			}
+			return true;
+		} else if (itemId == R.id.menu_downloadMoreItems) {
+			DownloadMoreItems();
+			return true;
+		} else if (itemId == R.id.menu_search) {
+			mSearchView.setIconified(false);
+			mSearchView.setFocusable(true);
+			mSearchView.requestFocusFromTouch();
+			return true;
+		} else if (itemId == R.id.menu_download_web_archive) {
+			checkAndStartDownloadWebPagesForOfflineReadingPermission();
+			return true;
 		}
 		return super.onOptionsItemSelected(item);
 	}
@@ -914,19 +899,13 @@ public class NewsReaderListActivity extends PodcastFragmentActivity implements
 		})
 				.subscribeOn(Schedulers.newThread())
 				.observeOn(AndroidSchedulers.mainThread())
-				.subscribe(new Action() {
-					@Override
-					public void run() throws Exception {
-						updateCurrentRssView();
-						Log.v(TAG, "Finished Download extra items..");
-					}
-				}, new Consumer<Throwable>() {
-					@Override
-					public void accept(@io.reactivex.annotations.NonNull Throwable throwable) throws Exception {
-						throwable.printStackTrace();
-						Throwable e = OkHttpSSLClient.HandleExceptions(throwable);
-						Toast.makeText(NewsReaderListActivity.this, getString(R.string.login_dialog_text_something_went_wrong) + " - " + e.getMessage(), Toast.LENGTH_SHORT).show();
-					}
+				.subscribe(() -> {
+					updateCurrentRssView();
+					Log.v(TAG, "Finished Download extra items..");
+				}, throwable -> {
+					throwable.printStackTrace();
+					Throwable e = OkHttpSSLClient.HandleExceptions(throwable);
+					Toast.makeText(NewsReaderListActivity.this, getString(R.string.login_dialog_text_something_went_wrong) + " - " + e.getMessage(), Toast.LENGTH_SHORT).show();
 				});
 	}
 
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListDialogFragment.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListDialogFragment.java
index 62c71275..6b72e27a 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListDialogFragment.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListDialogFragment.java
@@ -68,59 +68,42 @@ public class NewsReaderListDialogFragment extends DialogFragment {
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        ((NewsReaderApplication) getActivity().getApplication()).getAppComponent().injectFragment(this);
+        ((NewsReaderApplication) requireActivity().getApplication()).getAppComponent().injectFragment(this);
 
-        mFeedId = getArguments().getLong("feedid");
-        mDialogTitle = getArguments().getString("title");
-        mDialogIconUrl = getArguments().getString("iconurl");
-        mDialogText = getArguments().getString("feedurl");
+        final Bundle args = requireArguments();
+        mFeedId = args.getLong("feedid");
+        mDialogTitle = args.getString("title");
+        mDialogIconUrl = args.getString("iconurl");
+        mDialogText = args.getString("feedurl");
         mMenuItems = new LinkedHashMap<>();
 
-        mMenuItems.put(getString(R.string.action_feed_rename), new MenuAction() {
-            @Override
-            public void execute() {
-                showRenameFeedView(mFeedId, mDialogTitle);
-            }
-        });
+        mMenuItems.put(getString(R.string.action_feed_rename), () -> showRenameFeedView(mFeedId, mDialogTitle));
 
-        mMenuItems.put(getString(R.string.action_feed_remove), new MenuAction() {
-            @Override
-            public void execute() {
-                showRemoveFeedView(mFeedId);
-            }
-        });
+        mMenuItems.put(getString(R.string.action_feed_remove), () -> showRemoveFeedView(mFeedId));
 
-        mMenuItems.put(getString(R.string.action_feed_move), new MenuAction() {
-            @Override
-            public void execute() { showMoveFeedView(mFeedId); }
-        });
+        mMenuItems.put(getString(R.string.action_feed_move), () -> showMoveFeedView(mFeedId));
 
-        int style = DialogFragment.STYLE_NO_TITLE;
-        int theme = R.style.FloatingDialog;
-        setStyle(style, theme);
+        setStyle(DialogFragment.STYLE_NO_TITLE, R.style.FloatingDialog);
     }
 
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container,
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
 
         binding = FragmentDialogFeedoptionsBinding.inflate(inflater, container, false);
 
-        FavIconHandler favIconHandler = new FavIconHandler(getContext());
+        FavIconHandler favIconHandler = new FavIconHandler(requireContext());
         favIconHandler.loadFavIconForFeed(mDialogIconUrl, binding.icMenuFeedicon);
 
         binding.tvMenuTitle.setText(mDialogTitle);
         binding.tvMenuText.setText(mDialogText);
 
-        binding.tvMenuText.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                if (mDialogText != null) {
-                    Intent i = new Intent(Intent.ACTION_VIEW);
-                    i.setData(Uri.parse(mDialogText));
-                    startActivity(i);
-                }
+        binding.tvMenuText.setOnClickListener(v -> {
+            if (mDialogText != null) {
+                Intent i = new Intent(Intent.ACTION_VIEW);
+                i.setData(Uri.parse(mDialogText));
+                startActivity(i);
             }
         });
 
@@ -133,13 +116,10 @@ public class NewsReaderListDialogFragment extends DialogFragment {
 
         binding.lvMenuList.setAdapter(arrayAdapter);
 
-        binding.lvMenuList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
-            @Override
-            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
-                String key = arrayAdapter.getItem(i);
-                MenuAction mAction = mMenuItems.get(key);
-                mAction.execute();
-            }
+        binding.lvMenuList.setOnItemClickListener((adapterView, view, i, l) -> {
+            String key = arrayAdapter.getItem(i);
+            MenuAction mAction = mMenuItems.get(key);
+            mAction.execute();
         });
         return binding.getRoot();
     }
@@ -182,19 +162,11 @@ public class NewsReaderListDialogFragment extends DialogFragment {
             @Override
             public void onTextChanged(CharSequence s, int start,
                                       int before, int count) {
-                if (s.toString().equals(feedName) || s.length() == 0) {
-                    binding.buttonRenameConfirm.setEnabled(false);
-                } else {
-                    binding.buttonRenameConfirm.setEnabled(true);
-                }
+                binding.buttonRenameConfirm.setEnabled(!s.toString().equals(feedName) && s.length() != 0);
             }
         });
 
-        binding.buttonRenameCancel.setOnClickListener(new View.OnClickListener() {
-            public void onClick(View v) {
-                dismiss();
-            }
-        });
+        binding.buttonRenameCancel.setOnClickListener(v -> dismiss());
 
         binding.buttonRenameConfirm.setOnClickListener(new View.OnClickListener() {
             public void onClick(View v) {
@@ -208,23 +180,17 @@ public class NewsReaderListDialogFragment extends DialogFragment {
                 mApi.getNewsAPI().renameFeed(feedId, paramMap)
                         .subscribeOn(Schedulers.newThread())
                         .observeOn(AndroidSchedulers.mainThread())
-                        .subscribe(new Action() {
-                            @Override
-                            public void run() throws Exception {
-                                DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(getContext());
-                                dbConn.renameFeedById(mFeedId, binding.renamefeedFeedname.getText().toString());
-
-                                parentActivity.getSlidingListFragment().reloadAdapter();
-                                parentActivity.startSync();
-
-                                dismiss();
-                            }
-                        }, new Consumer<Throwable>() {
-                            @Override
-                            public void accept(@NonNull Throwable throwable) throws Exception {
-                                Toast.makeText(getContext().getApplicationContext(), getString(R.string.login_dialog_text_something_went_wrong) + " - " + throwable.getMessage(), Toast.LENGTH_LONG).show();
-                                dismiss();
-                            }
+                        .subscribe(() -> {
+                            DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(getContext());
+                            dbConn.renameFeedById(mFeedId, binding.renamefeedFeedname.getText().toString());
+
+                            parentActivity.getSlidingListFragment().reloadAdapter();
+                            parentActivity.startSync();
+
+                            dismiss();
+                        }, throwable -> {
+                            Toast.makeText(getContext().getApplicationContext(), getString(R.string.login_dialog_text_something_went_wrong) + " - " + throwable.getMessage(), Toast.LENGTH_LONG).show();
+                            dismiss();
                         });
             }
         });
@@ -235,45 +201,33 @@ public class NewsReaderListDialogFragment extends DialogFragment {
         binding.lvMenuList.setVisibility(View.GONE);
         binding.removeFeedDialog.setVisibility(View.VISIBLE);
 
-        binding.buttonRemoveCancel.setOnClickListener(new View.OnClickListener() {
-            public void onClick(View v) {
-                dismiss();
-            }
-        });
-
-        binding.buttonRemoveConfirm.setOnClickListener(new View.OnClickListener() {
-            public void onClick(View v) {
-                showProgress(true);
-                setCancelable(false);
-                getDialog().setCanceledOnTouchOutside(false);
-
-
-                mApi.getNewsAPI().deleteFeed(feedId)
-                        .subscribeOn(Schedulers.newThread())
-                        .observeOn(AndroidSchedulers.mainThread())
-                        .subscribe(new Action() {
-                            @Override
-                            public void run() throws Exception {
-                                DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(getContext());
-                                dbConn.removeFeedById(mFeedId);
-
-                                Long currentFeedId = parentActivity.getNewsReaderDetailFragment().getIdFeed();
-                                if(currentFeedId != null && currentFeedId == mFeedId) {
-                                    parentActivity.switchToAllUnreadItemsFolder();
-                                }
-                                parentActivity.getSlidingListFragment().reloadAdapter();
-                                parentActivity.updateCurrentRssView();
-
-                                dismiss();
-                            }
-                        }, new Consumer<Throwable>() {
-                            @Override
-                            public void accept(@NonNull Throwable throwable) throws Exception {
-                                Toast.makeText(getContext().getApplicationContext(), getString(R.string.login_dialog_text_something_went_wrong) + " - " + throwable.getMessage(), Toast.LENGTH_LONG).show();
-                                dismiss();
-                            }
-                        });
-            }
+        binding.buttonRemoveCancel.setOnClickListener(v -> dismiss());
+
+        binding.buttonRemoveConfirm.setOnClickListener(v -> {
+            showProgress(true);
+            setCancelable(false);
+            getDialog().setCanceledOnTouchOutside(false);
+
+
+            mApi.getNewsAPI().deleteFeed(feedId)
+                    .subscribeOn(Schedulers.newThread())
+                    .observeOn(AndroidSchedulers.mainThread())
+                    .subscribe(() -> {
+                        DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(getContext());
+                        dbConn.removeFeedById(mFeedId);
+
+                        Long currentFeedId = parentActivity.getNewsReaderDetailFragment().getIdFeed();
+                        if(currentFeedId != null && currentFeedId == mFeedId) {
+                            parentActivity.switchToAllUnreadItemsFolder();
+                        }
+                        parentActivity.getSlidingListFragment().reloadAdapter();
+                        parentActivity.updateCurrentRssView();
+
+                        dismiss();
+                    }, throwable -> {
+                        Toast.makeText(getContext().getApplicationContext(), getString(R.string.login_dialog_text_something_went_wrong) + " - " + throwable.getMessage(), Toast.LENGTH_LONG).show();
+                        dismiss();
+                    });
         });
     }
 
@@ -299,40 +253,31 @@ public class NewsReaderListDialogFragment extends DialogFragment {
 
         ArrayAdapter<String> folderAdapter = new ArrayAdapter<> (getActivity(), R.layout.dialog_list_folder, android.R.id.text1, folderNames);
         binding.folderList.setAdapter(folderAdapter);
-        binding.folderList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
-            @Override
-            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
-                final Folder folder = folders.get(position);
-
-                showProgress(true);
-                setCancelable(false);
-                getDialog().setCanceledOnTouchOutside(false);
-
-                Map<String, Long> paramMap = new LinkedHashMap<>();
-                paramMap.put("folderId", folder.getId());
-                mApi.getNewsAPI().moveFeed(mFeedId, paramMap)
-                        .subscribeOn(Schedulers.newThread())
-                        .observeOn(AndroidSchedulers.mainThread())
-                        .subscribe(new Action() {
-                            @Override
-                            public void run() {
-                                DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(getContext());
-                                Feed feed = dbConn.getFeedById(mFeedId);
-                                feed.setFolder(folder);
-
-                                parentActivity.getSlidingListFragment().reloadAdapter();
-                                parentActivity.startSync();
-
-                                dismiss();
-                            }
-                        }, new Consumer<Throwable>() {
-                            @Override
-                            public void accept(@NonNull Throwable throwable) throws Exception {
-                                Toast.makeText(getContext().getApplicationContext(), getString(R.string.login_dialog_text_something_went_wrong) + " - " + throwable.getMessage(), Toast.LENGTH_LONG).show();
-                                dismiss();
-                            }
-                        });
-            }
+        binding.folderList.setOnItemClickListener((parent, view, position, id) -> {
+            final Folder folder = folders.get(position);
+
+            showProgress(true);
+            setCancelable(false);
+            getDialog().setCanceledOnTouchOutside(false);
+
+            Map<String, Long> paramMap = new LinkedHashMap<>();
+            paramMap.put("folderId", folder.getId());
+            mApi.getNewsAPI().moveFeed(mFeedId, paramMap)
+                    .subscribeOn(Schedulers.newThread())
+                    .observeOn(AndroidSchedulers.mainThread())
+                    .subscribe(() -> {
+                        DatabaseConnectionOrm dbConn1 = new DatabaseConnectionOrm(getContext());
+                        Feed feed = dbConn1.getFeedById(mFeedId);
+                        feed.setFolder(folder);
+
+                        parentActivity.getSlidingListFragment().reloadAdapter();
+                        parentActivity.startSync();
+
+                        dismiss();
+                    }, throwable -> {
+                        Toast.makeText(getContext().getApplicationContext(), getString(R.string.login_dialog_text_something_went_wrong) + " - " + throwable.getMessage(), Toast.LENGTH_LONG).show();
+                        dismiss();
+                    });
         });
 
     }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListFragment.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListFragment.java
index 0d6112de..4b6d6ab1 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListFragment.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderListFragment.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -35,6 +35,7 @@ import android.widget.AdapterView;
 import android.widget.ExpandableListView;
 import android.widget.ExpandableListView.OnChildClickListener;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.VisibleForTesting;
 import androidx.fragment.app.Fragment;
 
@@ -59,7 +60,6 @@ import de.luhmer.owncloudnewsreader.model.ConcreteFeedItem;
 import de.luhmer.owncloudnewsreader.model.OcsUser;
 import io.reactivex.Observer;
 import io.reactivex.android.schedulers.AndroidSchedulers;
-import io.reactivex.annotations.NonNull;
 import io.reactivex.disposables.Disposable;
 import io.reactivex.schedulers.Schedulers;
 
@@ -92,7 +92,6 @@ public class NewsReaderListFragment extends Fragment implements OnCreateContextM
     private Callbacks mCallbacks = null;
 
 
-	@SuppressWarnings("unused")
 	protected static final String TAG = "NewsReaderListFragment";
 
     public void ListViewNotifyDataSetChanged()  {
@@ -141,12 +140,12 @@ public class NewsReaderListFragment extends Fragment implements OnCreateContextM
     @Override
     public void onCreate(Bundle savedInstance) {
         super.onCreate(savedInstance);
-        ((NewsReaderApplication) getActivity().getApplication()).getAppComponent().injectFragment(this);
+        ((NewsReaderApplication) requireActivity().getApplication()).getAppComponent().injectFragment(this);
     }
 
 	@Override
-	public View onCreateView(LayoutInflater inflater, ViewGroup container,
-			Bundle savedInstanceState) {
+	public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
+                            Bundle savedInstanceState) {
 	    binding = FragmentNewsreaderListBinding.inflate(requireActivity().getLayoutInflater(), container, false);
 
         lvAdapter = new SubscriptionExpandableListAdapter(getActivity(), new DatabaseConnectionOrm(getActivity()), binding.expandableListView, mPrefs);
@@ -161,12 +160,7 @@ public class NewsReaderListFragment extends Fragment implements OnCreateContextM
 		binding.expandableListView.setLongClickable(true);
 		binding.expandableListView.setAdapter(lvAdapter);
 
-		binding.headerView.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                ((NewsReaderListActivity) getActivity()).startSync();
-            }
-        });
+		binding.headerView.setOnClickListener(v -> ((NewsReaderListActivity) requireActivity()).startSync());
 
         lvAdapter.notifyDataSetChanged();
         reloadAdapter();
@@ -177,7 +171,7 @@ public class NewsReaderListFragment extends Fragment implements OnCreateContextM
 	}
 
 	@Override
-	public void onAttach(Context context) {
+	public void onAttach(@NonNull Context context) {
 		super.onAttach(context);
 
 		// Activities containing this fragment must implement its callbacks.
@@ -229,10 +223,10 @@ public class NewsReaderListFragment extends Fragment implements OnCreateContextM
                 case R.id.action_add_new_feed:
                     if(mApi.getNewsAPI() != null) {
                         Intent newFeedIntent = new Intent(getContext(), NewFeedActivity.class);
-                        getActivity().startActivityForResult(newFeedIntent, NewsReaderListActivity.RESULT_ADD_NEW_FEED);
+                        requireActivity().startActivityForResult(newFeedIntent, NewsReaderListActivity.RESULT_ADD_NEW_FEED);
                     } else {
                         Intent loginIntent = new Intent(getContext(), LoginDialogActivity.class);
-                        getActivity().startActivityForResult(loginIntent, RESULT_LOGIN);
+                        requireActivity().startActivityForResult(loginIntent, RESULT_LOGIN);
                     }
                     return true;
                 default:
@@ -242,7 +236,7 @@ public class NewsReaderListFragment extends Fragment implements OnCreateContextM
         list.addFooterView(footerView);
     }
 
-	private ExpListTextClicked expListTextClickedListener = new ExpListTextClicked() {
+	private final ExpListTextClicked expListTextClickedListener = new ExpListTextClicked() {
 
 		@Override
 		public void onTextClicked(long idFeed, boolean isFolder, Long optional_folder_id) {
@@ -284,23 +278,14 @@ public class NewsReaderListFragment extends Fragment implements OnCreateContextM
 		}
 	};
 
-	AdapterView.OnItemLongClickListener onItemLongClickListener = new AdapterView.OnItemLongClickListener() {
-
-		@Override
-		public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
-			if (ExpandableListView.getPackedPositionType(id) == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {
-				int childPosition = ExpandableListView.getPackedPositionChild(id);
-				mCallbacks.onChildItemLongClicked(childPosition);
-			}
-
-			return true;
-		}
-	};
-
+	AdapterView.OnItemLongClickListener onItemLongClickListener = (parent, view, position, id) -> {
+        if (ExpandableListView.getPackedPositionType(id) == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {
+            int childPosition = ExpandableListView.getPackedPositionChild(id);
+            mCallbacks.onChildItemLongClicked(childPosition);
+        }
 
-    public ExpandableListView getListView() {
-        return binding.expandableListView;
-    }
+        return true;
+    };
 
     public void startAsyncTaskGetUserInfo() {
         mApi.getServerAPI().user()
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/PodcastFragment.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/PodcastFragment.java
index bd54a090..fa417f34 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/PodcastFragment.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/PodcastFragment.java
@@ -214,7 +214,7 @@ public class PodcastFragment extends Fragment {
     }
 
     @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         // create ContextThemeWrapper from the original Activity Context with the custom theme
         //Context context = new ContextThemeWrapper(getActivity(), R.style.Theme_MaterialComponents_Light_DarkActionBar);
         // clone the inflater using the ContextThemeWrapper
@@ -259,7 +259,7 @@ public class PodcastFragment extends Fragment {
 
 
 
-    private SlidingUpPanelLayout.PanelSlideListener onPanelSlideListener = new SlidingUpPanelLayout.PanelSlideListener() {
+    private final SlidingUpPanelLayout.PanelSlideListener onPanelSlideListener = new SlidingUpPanelLayout.PanelSlideListener() {
         @Override
         public void onPanelSlide(View view, float v) { }
 
@@ -284,7 +284,7 @@ public class PodcastFragment extends Fragment {
 
 
     boolean blockSeekbarUpdate = false;
-    private SeekBar.OnSeekBarChangeListener onSeekBarChangeListener = new SeekBar.OnSeekBarChangeListener() {
+    private final SeekBar.OnSeekBarChangeListener onSeekBarChangeListener = new SeekBar.OnSeekBarChangeListener() {
         int before;
 
         @Override
@@ -335,7 +335,7 @@ public class PodcastFragment extends Fragment {
         numberPicker.setWrapSelectorWheel(false);
 
 
-        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(getActivity());
+        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(requireContext());
 
         // set title
         alertDialogBuilder.setTitle(getString(R.string.podcast_playback_speed_dialog_title));
@@ -371,7 +371,7 @@ public class PodcastFragment extends Fragment {
         }
     }
 
-    private MediaControllerCompat.Callback controllerCallback =
+    private final MediaControllerCompat.Callback controllerCallback =
             new MediaControllerCompat.Callback() {
                 @Override
                 public void onMetadataChanged(MediaMetadataCompat metadata) {
@@ -569,7 +569,7 @@ public class PodcastFragment extends Fragment {
     }
     */
 
-    private MediaControllerCompat.Callback mediaControllerCallback = new MediaControllerCompat.Callback() {
+    private final MediaControllerCompat.Callback mediaControllerCallback = new MediaControllerCompat.Callback() {
         @Override
         public void onSessionReady() {
             Log.d(TAG, "onSessionReady() called");
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/PodcastFragmentActivity.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/PodcastFragmentActivity.java
index d69e7c68..9c9b5f2b 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/PodcastFragmentActivity.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/PodcastFragmentActivity.java
@@ -261,7 +261,7 @@ public abstract class PodcastFragmentActivity extends AppCompatActivity implemen
         return (int) (px / Resources.getSystem().getDisplayMetrics().density);
     }
 
-    private float dipToPx(float dip) {
+    private float dipToPx(@SuppressWarnings("SameParameterValue") float dip) {
         return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dip, getResources().getDisplayMetrics());
     }
 
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsActivity.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsActivity.java
index e46dee5b..757ad2c4 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsActivity.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsActivity.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -27,7 +27,6 @@ import android.os.Bundle;
 import android.preference.PreferenceActivity;
 import android.view.MenuItem;
 
-import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
 
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsFragment.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsFragment.java
index e7b7dc23..aaab8c9e 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsFragment.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SettingsFragment.java
@@ -75,7 +75,7 @@ public class SettingsFragment extends PreferenceFragmentCompat {
 
     @Override
     public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
-        ((NewsReaderApplication) getActivity().getApplication()).getAppComponent().injectFragment(this);
+        ((NewsReaderApplication) requireActivity().getApplication()).getAppComponent().injectFragment(this);
 
         // Define the settings file to use by this settings fragment
         getPreferenceManager().setSharedPreferencesName(sharedPreferencesFileName);
@@ -126,7 +126,7 @@ public class SettingsFragment extends PreferenceFragmentCompat {
      * A preference value change listener that updates the preference's summary
      * to reflect its new value.
      */
-    private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = (preference, value) -> {
+    private static final Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = (preference, value) -> {
         String stringValue = value.toString();
 
         if (preference instanceof ListPreference) {
@@ -140,10 +140,8 @@ public class SettingsFragment extends PreferenceFragmentCompat {
 
             // only enable black-bg setting if light or auto theme is selected
             if(SP_APP_THEME.equals(preference.getKey())) {
-                if (value.equals("1")) 	// value "1" means Light theme
-                    preference.getPreferenceManager().findPreference(CB_OLED_MODE).setEnabled(false);
-                else
-                    preference.getPreferenceManager().findPreference(CB_OLED_MODE).setEnabled(true);
+                // value "1" means Light theme
+                preference.getPreferenceManager().findPreference(CB_OLED_MODE).setEnabled(!value.equals("1"));
             }
 
         } else {
@@ -158,7 +156,7 @@ public class SettingsFragment extends PreferenceFragmentCompat {
         return true;
     };
 
-    private static Preference.OnPreferenceChangeListener sBindPreferenceBooleanToValueListener = (preference, newValue) -> {
+    private static final Preference.OnPreferenceChangeListener sBindPreferenceBooleanToValueListener = (preference, newValue) -> {
         if(preference instanceof CheckBoxPreference) { //For legacy Android support
             CheckBoxPreference cbPreference = ((CheckBoxPreference) preference);
             cbPreference.setChecked((Boolean) newValue);
@@ -300,7 +298,7 @@ public class SettingsFragment extends PreferenceFragmentCompat {
         Preference changelogPreference = prefFrag.findPreference(CB_VERSION);
         changelogPreference.setOnPreferenceClickListener(preference -> {
             DialogFragment dialog = new VersionInfoDialogFragment();
-            dialog.show(prefFrag.getActivity().getFragmentManager(), "VersionChangelogDialogFragment");
+            dialog.show(prefFrag.requireActivity().getFragmentManager(), "VersionChangelogDialogFragment");
             return true;
         });
 
@@ -353,7 +351,7 @@ public class SettingsFragment extends PreferenceFragmentCompat {
         String debugInfo = "Please describe your bug here...\n\n---\n";
 
         try {
-            PackageInfo pInfo = getActivity().getPackageManager().getPackageInfo(getActivity().getPackageName(), 0);
+            PackageInfo pInfo = requireContext().getPackageManager().getPackageInfo(requireContext().getPackageName(), 0);
             debugInfo += "\nApp Version: " + pInfo.versionName;
             debugInfo += "\nApp Version Code: " + pInfo.versionCode;
         } catch (PackageManager.NameNotFoundException e) {
@@ -394,7 +392,7 @@ public class SettingsFragment extends PreferenceFragmentCompat {
     public static class ResetDatabaseAsyncTask extends AsyncTask<Void, Void, Void> {
 
         private ProgressDialog pd;
-        private Context context;
+        private final Context context;
 
         public ResetDatabaseAsyncTask(Context context) {
             this.context = context;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SyncIntervalSelectorActivity.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SyncIntervalSelectorActivity.java
index 59cf2b37..0ba46494 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SyncIntervalSelectorActivity.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/SyncIntervalSelectorActivity.java
@@ -43,9 +43,7 @@ public class SyncIntervalSelectorActivity extends AppCompatActivity {
         binding = ActivitySyncIntervalSelectorBinding.inflate(getLayoutInflater());
         setContentView(binding.getRoot());
 
-        if (binding.toolbarLayout.toolbar != null) {
-            setSupportActionBar(binding.toolbarLayout.toolbar);
-        }
+        setSupportActionBar(binding.toolbarLayout.toolbar);
 
         items_values = getResources().getStringArray(R.array.array_sync_interval_values);
 
@@ -132,7 +130,7 @@ public class SyncIntervalSelectorActivity extends AppCompatActivity {
         @Override
         public void onCreate(@Nullable Bundle savedInstanceState) {
             super.onCreate(savedInstanceState);
-            ((NewsReaderApplication) getActivity().getApplication()).getAppComponent().injectFragment(this);
+            ((NewsReaderApplication) requireActivity().getApplication()).getAppComponent().injectFragment(this);
         }
 
         @Override
@@ -152,7 +150,7 @@ public class SyncIntervalSelectorActivity extends AppCompatActivity {
 
             int position = 0;
             int minutes = mPrefs.getInt(SYNC_INTERVAL_IN_MINUTES_STRING, SYNC_DEFAULT_INTERVAL);
-            for (String item : ((SyncIntervalSelectorActivity) getActivity()).items_values) {
+            for (String item : ((SyncIntervalSelectorActivity) requireActivity()).items_values) {
                 if (Integer.parseInt(item) == minutes)
                     break;
                 position++;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/VersionInfoDialogFragment.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/VersionInfoDialogFragment.java
index e0aa1a84..499b5fd8 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/VersionInfoDialogFragment.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/VersionInfoDialogFragment.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -59,12 +59,7 @@ public class VersionInfoDialogFragment extends DialogFragment {
         // build dialog
         AlertDialog.Builder builder = new AlertDialog.Builder(getActivity())
                 .setView(view)
-                .setPositiveButton(getString(android.R.string.ok), new DialogInterface.OnClickListener() {
-                    @Override
-                    public void onClick(DialogInterface dialog, int which) {
-                        dismiss();
-                    }
-                })
+                .setPositiveButton(getString(android.R.string.ok), (dialog, which) -> dismiss())
                 .setCancelable(true) // React to click outside of version info
                 .setTitle("Changelog"); // changelog content is in english only anyways..
 
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/DividerItemDecoration.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/DividerItemDecoration.java
index fbeb21c2..81196684 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/DividerItemDecoration.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/DividerItemDecoration.java
@@ -7,12 +7,13 @@ import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
 import android.view.View;
 
+import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
 
 public class DividerItemDecoration extends RecyclerView.ItemDecoration {
 
-    private Drawable mDivider;
+    private final Drawable mDivider;
 
     private int size = 0;
 
@@ -25,8 +26,8 @@ public class DividerItemDecoration extends RecyclerView.ItemDecoration {
     }
 
     @Override
-    public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
-                               RecyclerView.State state) {
+    public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent,
+                               @NonNull RecyclerView.State state) {
         super.getItemOffsets(outRect, view, parent, state);
         if (mDivider == null || parent.getChildLayoutPosition(view) < 1) {
             return;
@@ -36,7 +37,7 @@ public class DividerItemDecoration extends RecyclerView.ItemDecoration {
     }
 
     @Override
-    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
+    public void onDraw(@NonNull Canvas c, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
         if(mDivider == null)
             return;
 
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/NewsListRecyclerAdapter.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/NewsListRecyclerAdapter.java
index d0e9936b..2d79a146 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/NewsListRecyclerAdapter.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/NewsListRecyclerAdapter.java
@@ -40,26 +40,27 @@ import de.luhmer.owncloudnewsreader.model.CurrentRssViewDataHolder;
 public class NewsListRecyclerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
     private static final String TAG = "NewsListRecyclerAdapter";
 
+    @SuppressWarnings("FieldCanBeLocal")
     private final int VIEW_ITEM = 1; // Item
     private final int VIEW_PROG = 0; // Progress
 
     private long idOfCurrentlyPlayedPodcast = -1;
 
     private List<RssItem> lazyList;
-    private DatabaseConnectionOrm dbConn;
-    private PostDelayHandler pDelayHandler;
-    private FragmentActivity activity;
+    private final DatabaseConnectionOrm dbConn;
+    private final PostDelayHandler pDelayHandler;
+    private final FragmentActivity activity;
 
     private int totalItemCount = 0;
     private int cachedPages = 1;
 
-    private IPlayPausePodcastClicked playPausePodcastClicked;
+    private final IPlayPausePodcastClicked playPausePodcastClicked;
 
     private boolean loading = false;
     // The minimum amount of items to have below your current scroll position
     // before loading more.
-    private int visibleThreshold = 5;
-    private SharedPreferences mPrefs;
+    private final int visibleThreshold = 5;
+    private final SharedPreferences mPrefs;
 
     public NewsListRecyclerAdapter(FragmentActivity activity, RecyclerView recyclerView, IPlayPausePodcastClicked playPausePodcastClicked, PostDelayHandler postDelayHandler, SharedPreferences prefs) {
         this.activity = activity;
@@ -155,8 +156,9 @@ public class NewsListRecyclerAdapter extends RecyclerView.Adapter<RecyclerView.V
         Log.v(TAG, "Updating Listview - Podcast completed");
     }
 
+    @NonNull
     @Override
-    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, @NonNull int viewType) {
+    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
         if (viewType == VIEW_PROG) {
             View v = LayoutInflater.from(parent.getContext()).inflate(
                     R.layout.progressbar_item, parent, false);
@@ -355,7 +357,7 @@ public class NewsListRecyclerAdapter extends RecyclerView.Adapter<RecyclerView.V
 
     private class RefreshDataAsyncTask extends AsyncTask<Void, Void, List<RssItem>> {
 
-        private IOnRefreshFinished listener;
+        private final IOnRefreshFinished listener;
 
         public RefreshDataAsyncTask(IOnRefreshFinished listener) {
             this.listener = listener;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/ProgressBarWebChromeClient.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/ProgressBarWebChromeClient.java
index c0423600..6bcdaa3b 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/ProgressBarWebChromeClient.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/ProgressBarWebChromeClient.java
@@ -15,7 +15,7 @@ public class ProgressBarWebChromeClient extends WebChromeClient {
 
     public final String TAG = getClass().getCanonicalName();
 
-    private ProgressBar mProgressBar;
+    private final ProgressBar mProgressBar;
 
     public ProgressBarWebChromeClient(ProgressBar progressBar) {
         mProgressBar = progressBar;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/RssItemViewHolder.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/RssItemViewHolder.java
index c727ddeb..f6bac358 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/RssItemViewHolder.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/adapter/RssItemViewHolder.java
@@ -42,6 +42,7 @@ public abstract class RssItemViewHolder<T extends ViewBinding> extends RecyclerV
     private static final SparseIntArray downloadProgressList = new SparseIntArray();
     private static FavIconHandler favIconHandler = null;
     protected final SharedPreferences mPrefs;
+    @SuppressWarnings("FieldCanBeLocal")
     private final int LengthBody = 400;
     private final ForegroundColorSpan bodyForegroundColor;
     private RecyclerItemClickListener clickListener;
@@ -51,7 +52,7 @@ public abstract class RssItemViewHolder<T extends ViewBinding> extends RecyclerV
     private int starColor;
     private int inactiveStarColor;
 
-    private SparseIntArray initalFontSizes = new SparseIntArray();
+    private final SparseIntArray initalFontSizes = new SparseIntArray();
 
     RssItemViewHolder(@NonNull ViewBinding binding, SharedPreferences sharedPreferences) {
         super(binding.getRoot());
@@ -273,6 +274,7 @@ public abstract class RssItemViewHolder<T extends ViewBinding> extends RecyclerV
         return rssItem;
     }
 
+    @SuppressWarnings("BooleanMethodIsAlwaysInverted")
     public boolean shouldStayUnread() {
         return stayUnread;
     }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/async_tasks/DownloadChangelogTask.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/async_tasks/DownloadChangelogTask.java
index d43ffab6..643e667f 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/async_tasks/DownloadChangelogTask.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/async_tasks/DownloadChangelogTask.java
@@ -24,15 +24,14 @@ import de.luhmer.owncloudnewsreader.view.ChangeLogFileListView;
  */
 public class DownloadChangelogTask extends AsyncTask<Void, Void, String> {
 
-    @SuppressWarnings("unused")
     private static final String TAG = "DownloadChangelogTask";
 
     private static final String README_URL = "https://raw.githubusercontent.com/nextcloud/news-android/master/CHANGELOG.md";
     private static final String FILE_NAME = "changelog.xml";
 
-    private Context mContext;
-    private ChangeLogFileListView mChangelogView;
-    private Listener mListener;
+    private final Context mContext;
+    private final ChangeLogFileListView mChangelogView;
+    private final Listener mListener;
     private IOException exception;
 
     /**
@@ -126,7 +125,7 @@ public class DownloadChangelogTask extends AsyncTask<Void, Void, String> {
             } else if (!line.contains("---------------------")) {
                 // version start
                 versionStarted = true;
-                builder.append("<changelogversion versionName=\"" + line + "\">");
+                builder.append("<changelogversion versionName=\"").append(line).append("\">");
             }
         }
 
@@ -135,14 +134,11 @@ public class DownloadChangelogTask extends AsyncTask<Void, Void, String> {
         return builder.toString();
     }
 
-    private String saveToTempFile(String content, String fileName) throws IOException {
+    private String saveToTempFile(String content, @SuppressWarnings("SameParameterValue") String fileName) throws IOException {
         File file = File.createTempFile(fileName, null, mContext.getCacheDir());
-        BufferedWriter out = new BufferedWriter(new FileWriter(file));
 
-        try {
+        try (BufferedWriter out = new BufferedWriter(new FileWriter(file))) {
             out.write(content);
-        } finally {
-            out.close();
         }
 
         return "file://" + file.getAbsolutePath();
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/async_tasks/DownloadImageHandler.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/async_tasks/DownloadImageHandler.java
index f41f904d..653ed5ec 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/async_tasks/DownloadImageHandler.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/async_tasks/DownloadImageHandler.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/authentication/OwnCloudAccountAuthenticator.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/authentication/OwnCloudAccountAuthenticator.java
index 104494c8..19c551c1 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/authentication/OwnCloudAccountAuthenticator.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/authentication/OwnCloudAccountAuthenticator.java
@@ -17,7 +17,7 @@ import static android.accounts.AccountManager.KEY_BOOLEAN_RESULT;
 
 public class OwnCloudAccountAuthenticator extends AbstractAccountAuthenticator {
 
-    private String TAG = "UdinicAuthenticator";
+    private static final String TAG = "UdinicAuthenticator";
     private final Context mContext;
 
     public OwnCloudAccountAuthenticator(Context context) {
@@ -28,7 +28,7 @@ public class OwnCloudAccountAuthenticator extends AbstractAccountAuthenticator {
     }
 
     @Override
-    public Bundle addAccount(AccountAuthenticatorResponse response, String accountType, String authTokenType, String[] requiredFeatures, Bundle options) throws NetworkErrorException {
+    public Bundle addAccount(AccountAuthenticatorResponse response, String accountType, String authTokenType, String[] requiredFeatures, Bundle options) {
         Log.d("udinic", TAG + "> addAccount");
 
         final Intent intent = new Intent(mContext, LoginDialogActivity.class);
@@ -43,7 +43,7 @@ public class OwnCloudAccountAuthenticator extends AbstractAccountAuthenticator {
     }
 
     @Override
-    public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
+    public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) {
 
         Log.d("udinic", TAG + "> getAuthToken");
 
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/authentication/OwnCloudSyncAdapter.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/authentication/OwnCloudSyncAdapter.java
index 90e42a69..c72b8564 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/authentication/OwnCloudSyncAdapter.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/authentication/OwnCloudSyncAdapter.java
@@ -96,7 +96,7 @@ public class OwnCloudSyncAdapter extends AbstractThreadedSyncAdapter {
 
 
 
-    private class NextcloudSyncResult {
+    private static class NextcloudSyncResult {
         private final List<Folder> folders;
         private final List<Feed>   feeds;
         private final boolean      stateSyncSuccessful;
@@ -122,17 +122,14 @@ public class OwnCloudSyncAdapter extends AbstractThreadedSyncAdapter {
         final DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(getContext());
 
         Observable<Boolean> rssStateSync = Observable.fromPublisher(
-                new Publisher<Boolean>() {
-                    @Override
-                    public void subscribe(Subscriber<? super Boolean> s) {
-                        Log.v(TAG, "(rssStateSync) subscribe() called with: s = [" + s + "] [" + Thread.currentThread().getName() + "]");
-                        try {
-                            boolean success = ItemStateSync.PerformItemStateSync(mApi.getNewsAPI(), dbConn);
-                            s.onNext(success);
-                            s.onComplete();
-                        } catch(Exception ex) {
-                            s.onError(ex);
-                        }
+                (Publisher<Boolean>) s -> {
+                    Log.v(TAG, "(rssStateSync) subscribe() called with: s = [" + s + "] [" + Thread.currentThread().getName() + "]");
+                    try {
+                        boolean success = ItemStateSync.PerformItemStateSync(mApi.getNewsAPI(), dbConn);
+                        s.onNext(success);
+                        s.onComplete();
+                    } catch(Exception ex) {
+                        s.onError(ex);
                     }
                 }).subscribeOn(Schedulers.newThread());
 
@@ -148,12 +145,9 @@ public class OwnCloudSyncAdapter extends AbstractThreadedSyncAdapter {
                 .subscribeOn(Schedulers.newThread());
 
         // Wait for results
-        Observable<NextcloudSyncResult> combined = Observable.zip(folderObservable, feedsObservable, rssStateSync, new Function3<List<Folder>, List<Feed>, Boolean, NextcloudSyncResult>() {
-            @Override
-            public NextcloudSyncResult apply(@NonNull List<Folder> folders, @NonNull List<Feed> feeds, @NonNull Boolean mRes) {
-                Log.v(TAG, "apply() called with: folders = [" + folders + "], feeds = [" + feeds + "], mRes = [" + mRes + "] [" + Thread.currentThread().getName() + "]");
-                return new NextcloudSyncResult(folders, feeds, mRes);
-            }
+        Observable<NextcloudSyncResult> combined = Observable.zip(folderObservable, feedsObservable, rssStateSync, (folders, feeds, mRes) -> {
+            Log.v(TAG, "apply() called with: folders = [" + folders + "], feeds = [" + feeds + "], mRes = [" + mRes + "] [" + Thread.currentThread().getName() + "]");
+            return new NextcloudSyncResult(folders, feeds, mRes);
         });
 
         Log.v(TAG, "subscribing now.. [" + Thread.currentThread().getName() + "]");
@@ -192,15 +186,10 @@ public class OwnCloudSyncAdapter extends AbstractThreadedSyncAdapter {
                         Log.v(TAG, "[syncRssItems] - onNext() called with: totalCount = [" + totalCount + "]");
 
                         Handler handler = new Handler(Looper.getMainLooper());
-                        handler.post(new Runnable() {
-                            @Override
-                            public void run() {
-                                Toast.makeText(
-                                        getContext(),
-                                        getContext().getResources().getQuantityString(R.plurals.fetched_items_so_far, totalCount, totalCount),
-                                        Toast.LENGTH_SHORT).show();
-                            }
-                        });
+                        handler.post(() -> Toast.makeText(
+                                getContext(),
+                                getContext().getResources().getQuantityString(R.plurals.fetched_items_so_far, totalCount, totalCount),
+                                Toast.LENGTH_SHORT).show());
                     }
 
                     @Override
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/chrometabs/CustomTabActivityManager.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/chrometabs/CustomTabActivityManager.java
index aa7675cb..cbe1cb3f 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/chrometabs/CustomTabActivityManager.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/chrometabs/CustomTabActivityManager.java
@@ -128,7 +128,7 @@ public class CustomTabActivityManager {
             List<ResolveInfo> handlers = pm.queryIntentActivities(
                     intent,
                     PackageManager.GET_RESOLVED_FILTER);
-            if (handlers == null || handlers.size() == 0) {
+            if (handlers.size() == 0) {
                 return false;
             }
             for (ResolveInfo resolveInfo : handlers) {
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/DatabaseConnectionOrm.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/DatabaseConnectionOrm.java
index 0589ee7b..37b4557e 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/DatabaseConnectionOrm.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/DatabaseConnectionOrm.java
@@ -61,7 +61,7 @@ public class DatabaseConnectionOrm {
     private static final String[] VIDEO_FORMATS = { "video/mp4" };
     public enum SORT_DIRECTION { asc, desc }
 
-    private DaoSession daoSession;
+    private final DaoSession daoSession;
 
     private final static int PageSize = 100;
 
@@ -314,8 +314,13 @@ public class DatabaseConnectionOrm {
         List<RssItem> rssItemList;
         do {
             int offset = iterationCount * itemsPerIteration;
-            int limit = itemsPerIteration;
-            rssItemList = daoSession.getRssItemDao().queryBuilder().where(whereCondition).limit(limit).offset(offset).listLazy();
+            rssItemList = daoSession
+                    .getRssItemDao()
+                    .queryBuilder()
+                    .where(whereCondition)
+                    .limit(itemsPerIteration)
+                    .offset(offset)
+                    .listLazy();
             for (RssItem rssItem : rssItemList) {
                 rssItem.setRead_temp(true);
             }
@@ -394,7 +399,7 @@ public class DatabaseConnectionOrm {
 
     class UpdateRssItemAsyncTask extends AsyncTask<Void, Void, Void> {
 
-        private RssItem rssItem;
+        private final RssItem rssItem;
 
         UpdateRssItemAsyncTask(RssItem rssItem) {
             this.rssItem = rssItem;
@@ -665,13 +670,9 @@ public class DatabaseConnectionOrm {
 
         int totalUnreadItemsCount = 0;
 
-        Cursor cursor = daoSession.getDatabase().rawQuery(buildSQL, null);
-        try
-        {
-            if(cursor != null)
-            {
-                if(cursor.getCount() > 0)
-                {
+        try (Cursor cursor = daoSession.getDatabase().rawQuery(buildSQL, null)) {
+            if (cursor != null) {
+                if (cursor.getCount() > 0) {
                     cursor.moveToFirst();
                     do {
                         int folderId = cursor.getInt(0);
@@ -681,18 +682,16 @@ public class DatabaseConnectionOrm {
                         totalUnreadItemsCount += unreadCount;
 
                         values[1].put(feedId, String.valueOf(unreadCount));
-                        if(folderId != 0) {
-                            if(values[0].get(folderId) != null) {
+                        if (folderId != 0) {
+                            if (values[0].get(folderId) != null) {
                                 unreadCount += Integer.parseInt(values[0].get(folderId));
                             }
 
                             values[0].put(folderId, String.valueOf(unreadCount));
                         }
-                    } while(cursor.moveToNext());
+                    } while (cursor.moveToNext());
                 }
             }
-        } finally {
-            cursor.close();
         }
 
 
@@ -791,14 +790,10 @@ public class DatabaseConnectionOrm {
     {
         long result = -1;
 
-        Cursor cursor = daoSession.getDatabase().rawQuery(buildSQL, null);
-        try
-        {
-            if(cursor != null && cursor.moveToFirst()) {
+        try (Cursor cursor = daoSession.getDatabase().rawQuery(buildSQL, null)) {
+            if (cursor != null && cursor.moveToFirst()) {
                 result = cursor.getLong(0);
             }
-        } finally {
-            cursor.close();
         }
 
         return result;
@@ -807,23 +802,17 @@ public class DatabaseConnectionOrm {
     public SparseArray<Integer> getIntegerSparseArrayFromSQL(String buildSQL, int indexKey, int indexValue) {
         SparseArray<Integer> result = new SparseArray<>();
 
-        Cursor cursor = daoSession.getDatabase().rawQuery(buildSQL, null);
-        try
-        {
-            if(cursor != null)
-            {
-                if(cursor.getCount() > 0)
-                {
+        try (Cursor cursor = daoSession.getDatabase().rawQuery(buildSQL, null)) {
+            if (cursor != null) {
+                if (cursor.getCount() > 0) {
                     cursor.moveToFirst();
                     do {
                         int key = cursor.getInt(indexKey);
                         Integer value = cursor.getInt(indexValue);
                         result.put(key, value);
-                    } while(cursor.moveToNext());
+                    } while (cursor.moveToNext());
                 }
             }
-        } finally {
-            cursor.close();
         }
 
         return result;
@@ -832,23 +821,17 @@ public class DatabaseConnectionOrm {
     public SparseArray<String> getStringSparseArrayFromSQL(String buildSQL, int indexKey, int indexValue) {
         SparseArray<String> result = new SparseArray<>();
 
-        Cursor cursor = daoSession.getDatabase().rawQuery(buildSQL, null);
-        try
-        {
-            if(cursor != null)
-            {
-                if(cursor.getCount() > 0)
-                {
+        try (Cursor cursor = daoSession.getDatabase().rawQuery(buildSQL, null)) {
+            if (cursor != null) {
+                if (cursor.getCount() > 0) {
                     cursor.moveToFirst();
                     do {
                         int key = cursor.getInt(indexKey);
                         String value = cursor.getString(indexValue);
                         result.put(key, value);
-                    } while(cursor.moveToNext());
+                    } while (cursor.moveToNext());
                 }
             }
-        } finally {
-            cursor.close();
         }
 
         return result;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/DatabaseHelperOrm.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/DatabaseHelperOrm.java
index 1c48237f..6da86f56 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/DatabaseHelperOrm.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/DatabaseHelperOrm.java
@@ -1,5 +1,5 @@
-/**
- * Android ownCloud News
+/*
+* Android ownCloud News
  *
  * @author David Luhmer
  * @copyright 2013 David Luhmer david-dev@live.de
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/generator/DatabaseOrmGenerator.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/generator/DatabaseOrmGenerator.java
index ef5ef537..0dea1d78 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/generator/DatabaseOrmGenerator.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/generator/DatabaseOrmGenerator.java
@@ -17,11 +17,6 @@ public class DatabaseOrmGenerator {
      * (including older versions used for migration test purposes) and ensures
      * business rules are met; these include ensuring we only have a single
      * current schema instance and the version numbering is correct.
-     *
-     * @param args
-     *
-     * @throws Exception
-     * @throws IOException
      */
     public static void main(String[] args) throws Exception {
         List<SchemaVersion> versions = new ArrayList<>();
@@ -42,7 +37,6 @@ public class DatabaseOrmGenerator {
     /**
      * Validate the schema, throws
      *
-     * @param versions
      * @throws IllegalArgumentException
      *             if data is invalid
      */
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/CurrentRssItemViewDao.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/CurrentRssItemViewDao.java
index 44613799..399bfbc0 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/CurrentRssItemViewDao.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/CurrentRssItemViewDao.java
@@ -48,7 +48,6 @@ public class CurrentRssItemViewDao extends AbstractDao<CurrentRssItemView, Long>
         db.execSQL(sql);
     }
 
-    /** @inheritdoc */
     @Override
     protected void bindValues(SQLiteStatement stmt, CurrentRssItemView entity) {
         stmt.clearBindings();
@@ -56,37 +55,31 @@ public class CurrentRssItemViewDao extends AbstractDao<CurrentRssItemView, Long>
         stmt.bindLong(2, entity.getRssItemId());
     }
 
-    /** @inheritdoc */
     @Override
     public Long readKey(Cursor cursor, int offset) {
-        return cursor.getLong(offset + 0);
+        return cursor.getLong(offset);
     }    
 
-    /** @inheritdoc */
     @Override
     public CurrentRssItemView readEntity(Cursor cursor, int offset) {
-        CurrentRssItemView entity = new CurrentRssItemView( //
-            cursor.getLong(offset + 0), // id
+        return new CurrentRssItemView( //
+            cursor.getLong(offset), // id
             cursor.getLong(offset + 1) // rssItemId
         );
-        return entity;
     }
      
-    /** @inheritdoc */
     @Override
     public void readEntity(Cursor cursor, CurrentRssItemView entity, int offset) {
-        entity.setId(cursor.getLong(offset + 0));
+        entity.setId(cursor.getLong(offset));
         entity.setRssItemId(cursor.getLong(offset + 1));
      }
     
-    /** @inheritdoc */
     @Override
     protected Long updateKeyAfterInsert(CurrentRssItemView entity, long rowId) {
         entity.setId(rowId);
         return rowId;
     }
     
-    /** @inheritdoc */
     @Override
     public Long getKey(CurrentRssItemView entity) {
         if(entity != null) {
@@ -96,8 +89,7 @@ public class CurrentRssItemViewDao extends AbstractDao<CurrentRssItemView, Long>
         }
     }
 
-    /** @inheritdoc */
-    @Override    
+    @Override
     protected boolean isEntityUpdateable() {
         return true;
     }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/FeedDao.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/FeedDao.java
index be654579..18d62970 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/FeedDao.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/FeedDao.java
@@ -106,27 +106,26 @@ public class FeedDao extends AbstractDao<Feed, Long> {
     /** @inheritdoc */
     @Override
     public Long readKey(Cursor cursor, int offset) {
-        return cursor.getLong(offset + 0);
+        return cursor.getLong(offset);
     }    
 
     /** @inheritdoc */
     @Override
     public Feed readEntity(Cursor cursor, int offset) {
-        Feed entity = new Feed( //
-            cursor.getLong(offset + 0), // id
+        return new Feed( //
+            cursor.getLong(offset), // id
             cursor.isNull(offset + 1) ? null : cursor.getLong(offset + 1), // folderId
             cursor.getString(offset + 2), // feedTitle
             cursor.isNull(offset + 3) ? null : cursor.getString(offset + 3), // faviconUrl
             cursor.isNull(offset + 4) ? null : cursor.getString(offset + 4), // link
             cursor.isNull(offset + 5) ? null : cursor.getString(offset + 5) // avgColour
         );
-        return entity;
     }
      
     /** @inheritdoc */
     @Override
     public void readEntity(Cursor cursor, Feed entity, int offset) {
-        entity.setId(cursor.getLong(offset + 0));
+        entity.setId(cursor.getLong(offset));
         entity.setFolderId(cursor.isNull(offset + 1) ? null : cursor.getLong(offset + 1));
         entity.setFeedTitle(cursor.getString(offset + 2));
         entity.setFaviconUrl(cursor.isNull(offset + 3) ? null : cursor.getString(offset + 3));
@@ -209,9 +208,8 @@ public class FeedDao extends AbstractDao<Feed, Long> {
         String sql = builder.toString();
         
         String[] keyArray = new String[] { key.toString() };
-        Cursor cursor = db.rawQuery(sql, keyArray);
-        
-        try {
+
+        try (Cursor cursor = db.rawQuery(sql, keyArray)) {
             boolean available = cursor.moveToFirst();
             if (!available) {
                 return null;
@@ -219,8 +217,6 @@ public class FeedDao extends AbstractDao<Feed, Long> {
                 throw new IllegalStateException("Expected unique result, but count was " + cursor.getCount());
             }
             return loadCurrentDeep(cursor, true);
-        } finally {
-            cursor.close();
         }
     }
     
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/FolderDao.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/FolderDao.java
index 30537be8..f43b942d 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/FolderDao.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/FolderDao.java
@@ -68,23 +68,22 @@ public class FolderDao extends AbstractDao<Folder, Long> {
     /** @inheritdoc */
     @Override
     public Long readKey(Cursor cursor, int offset) {
-        return cursor.getLong(offset + 0);
+        return cursor.getLong(offset);
     }    
 
     /** @inheritdoc */
     @Override
     public Folder readEntity(Cursor cursor, int offset) {
-        Folder entity = new Folder( //
-            cursor.getLong(offset + 0), // id
+        return new Folder( //
+            cursor.getLong(offset), // id
             cursor.getString(offset + 1) // label
         );
-        return entity;
     }
      
     /** @inheritdoc */
     @Override
     public void readEntity(Cursor cursor, Folder entity, int offset) {
-        entity.setId(cursor.getLong(offset + 0));
+        entity.setId(cursor.getLong(offset));
         entity.setLabel(cursor.getString(offset + 1));
      }
     
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/RssItemDao.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/RssItemDao.java
index ba4e1139..38f19bc8 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/RssItemDao.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/database/model/RssItemDao.java
@@ -188,14 +188,14 @@ public class RssItemDao extends AbstractDao<RssItem, Long> {
     /** @inheritdoc */
     @Override
     public Long readKey(Cursor cursor, int offset) {
-        return cursor.getLong(offset + 0);
+        return cursor.getLong(offset);
     }    
 
     /** @inheritdoc */
     @Override
     public RssItem readEntity(Cursor cursor, int offset) {
-        RssItem entity = new RssItem( //
-            cursor.getLong(offset + 0), // id
+        return new RssItem( //
+            cursor.getLong(offset), // id
             cursor.getLong(offset + 1), // feedId
             cursor.isNull(offset + 2) ? null : cursor.getString(offset + 2), // link
             cursor.isNull(offset + 3) ? null : cursor.getString(offset + 3), // title
@@ -216,13 +216,12 @@ public class RssItemDao extends AbstractDao<RssItem, Long> {
             cursor.isNull(offset + 18) ? null : cursor.getString(offset + 18), // mediaDescription
             cursor.isNull(offset + 19) ? null : cursor.getShort(offset + 19) != 0 // rtl
         );
-        return entity;
     }
      
     /** @inheritdoc */
     @Override
     public void readEntity(Cursor cursor, RssItem entity, int offset) {
-        entity.setId(cursor.getLong(offset + 0));
+        entity.setId(cursor.getLong(offset));
         entity.setFeedId(cursor.getLong(offset + 1));
         entity.setLink(cursor.isNull(offset + 2) ? null : cursor.getString(offset + 2));
         entity.setTitle(cursor.isNull(offset + 3) ? null : cursor.getString(offset + 3));
@@ -321,9 +320,8 @@ public class RssItemDao extends AbstractDao<RssItem, Long> {
         String sql = builder.toString();
         
         String[] keyArray = new String[] { key.toString() };
-        Cursor cursor = db.rawQuery(sql, keyArray);
-        
-        try {
+
+        try (Cursor cursor = db.rawQuery(sql, keyArray)) {
             boolean available = cursor.moveToFirst();
             if (!available) {
                 return null;
@@ -331,8 +329,6 @@ public class RssItemDao extends AbstractDao<RssItem, Long> {
                 throw new IllegalStateException("Expected unique result, but count was " + cursor.getCount());
             }
             return loadCurrentDeep(cursor, true);
-        } finally {
-            cursor.close();
         }
     }
     
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/di/ApiModule.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/di/ApiModule.java
index 760471e2..1c62a6e5 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/di/ApiModule.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/di/ApiModule.java
@@ -26,7 +26,7 @@ import okhttp3.OkHttpClient;
 @Module
 public class ApiModule {
 
-    private Application mApplication;
+    private final Application mApplication;
 
     public ApiModule(Application application) {
         this.mApplication = application;
@@ -86,9 +86,8 @@ public class ApiModule {
     @Provides
     @Singleton
     OkHttpClient provideOkHttpClient(Cache cache) {
-        OkHttpClient client = new OkHttpClient();
-        //client.setCache(cache);
-        return client;
+        // setCache(cache);
+        return new OkHttpClient();
     }
 
     @Provides
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/events/podcast/UpdatePodcastStatusEvent.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/events/podcast/UpdatePodcastStatusEvent.java
index 7e85eb09..846fa72a 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/events/podcast/UpdatePodcastStatusEvent.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/events/podcast/UpdatePodcastStatusEvent.java
@@ -6,14 +6,15 @@ import de.luhmer.owncloudnewsreader.services.podcast.PlaybackService;
 
 public class UpdatePodcastStatusEvent {
 
-    private long current;
-    private long max;
-    private String author;
-    private String title;
-    private @PlaybackStateCompat.State int status;
-    private PlaybackService.VideoType videoType;
-    private long rssItemId;
-    private float speed;
+    private final long current;
+    private final long max;
+    private final String author;
+    private final String title;
+    private @PlaybackStateCompat.State
+    final int status;
+    private final PlaybackService.VideoType videoType;
+    private final long rssItemId;
+    private final float speed;
 
     public long getRssItemId() {
         return rssItemId;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/AutoResizeTextView.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/AutoResizeTextView.java
index b6af7fbc..548e7a86 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/AutoResizeTextView.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/AutoResizeTextView.java
@@ -16,6 +16,7 @@ package de.luhmer.owncloudnewsreader.helper;
  *  0. You just DO WHAT THE FUCK YOU WANT TO.
  */
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.text.Layout.Alignment;
 import android.text.StaticLayout;
@@ -233,6 +234,7 @@ public class AutoResizeTextView extends AppCompatTextView {
      * @param width
      * @param height
      */
+    @SuppressLint("SetTextI18n")
     public void resizeText(int width, int height) {
         CharSequence text = getText();
         // Do not resize if the view does not have dimensions or there is no text
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ColorHelper.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ColorHelper.java
index 25df2a90..23b03c0d 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ColorHelper.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ColorHelper.java
@@ -1,5 +1,6 @@
 package de.luhmer.owncloudnewsreader.helper;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.res.TypedArray;
 import android.graphics.Color;
@@ -8,6 +9,7 @@ import de.luhmer.owncloudnewsreader.R;
 import de.luhmer.owncloudnewsreader.database.model.Feed;
 
 public class ColorHelper {
+    @SuppressLint("DefaultLocale")
     public static String getCssColor(int color) {
         // using %f for the double value would result in a localized string, e.g. 0,12 which
         // would be an invalid css color string
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/DatabaseUtils.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/DatabaseUtils.java
index ea73cf04..384ce1a7 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/DatabaseUtils.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/DatabaseUtils.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/FavIconHandler.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/FavIconHandler.java
index b0176d22..4613a77c 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/FavIconHandler.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/FavIconHandler.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ForegroundListener.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ForegroundListener.java
index 5d4a8e9c..4c63cc03 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ForegroundListener.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ForegroundListener.java
@@ -4,6 +4,8 @@ import android.app.Activity;
 import android.app.Application;
 import android.os.Bundle;
 
+import androidx.annotation.NonNull;
+
 public class ForegroundListener implements Application.ActivityLifecycleCallbacks {
 
     private static int numStarted;
@@ -13,37 +15,37 @@ public class ForegroundListener implements Application.ActivityLifecycleCallback
     }
 
     @Override
-    public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
+    public void onActivityCreated(@NonNull Activity activity, Bundle savedInstanceState) {
         // do nothing
     }
 
     @Override
-    public void onActivityStarted(Activity activity) {
+    public void onActivityStarted(@NonNull Activity activity) {
         numStarted++;
     }
 
     @Override
-    public void onActivityResumed(Activity activity) {
+    public void onActivityResumed(@NonNull Activity activity) {
         // do nothing
     }
 
     @Override
-    public void onActivityPaused(Activity activity) {
+    public void onActivityPaused(@NonNull Activity activity) {
         // do nothing
     }
 
     @Override
-    public void onActivityStopped(Activity activity) {
+    public void onActivityStopped(@NonNull Activity activity) {
         numStarted--;
     }
 
     @Override
-    public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
+    public void onActivitySaveInstanceState(@NonNull Activity activity, @NonNull Bundle outState) {
         // do nothing
     }
 
     @Override
-    public void onActivityDestroyed(Activity activity) {
+    public void onActivityDestroyed(@NonNull Activity activity) {
         // do nothing
     }
 }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ImageDownloadFinished.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ImageDownloadFinished.java
index b4fe6268..11b50a14 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ImageDownloadFinished.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ImageDownloadFinished.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ImageHandler.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ImageHandler.java
index 48352bff..1b838342 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ImageHandler.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ImageHandler.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -42,7 +42,7 @@ public class ImageHandler {
 	    	Matcher matcherSrcLink = patternImgSrcLink.matcher(matcher.group());
 	    	if(matcherSrcLink.find()) {
                 String link = matcherSrcLink.group(1);
-                if(link.startsWith("//")) { //Maybe the text contains image urls without http or https prefix.
+                if(link != null && link.startsWith("//")) { //Maybe the text contains image urls without http or https prefix.
                     link = "https:" + link;
                 }
 	    		links.add(link);
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NetworkConnection.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NetworkConnection.java
index 5754a615..7ce267f3 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NetworkConnection.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NetworkConnection.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NewsFileUtils.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NewsFileUtils.java
index 851d4a61..62dc60bf 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NewsFileUtils.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NewsFileUtils.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NotificationActionReceiver.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NotificationActionReceiver.java
index 43672dc9..13663682 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NotificationActionReceiver.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/NotificationActionReceiver.java
@@ -4,8 +4,11 @@ import android.app.NotificationManager;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
+import android.os.Build;
 import android.util.Log;
 
+import androidx.annotation.RequiresApi;
+
 import org.greenrobot.eventbus.EventBus;
 
 import de.luhmer.owncloudnewsreader.database.DatabaseConnectionOrm;
@@ -17,6 +20,7 @@ import static de.luhmer.owncloudnewsreader.Constants.NOTIFICATION_ACTION_MARK_AL
 public class NotificationActionReceiver extends BroadcastReceiver {
     private static final String TAG = NotificationActionReceiver.class.getCanonicalName();
 
+    @RequiresApi(api = Build.VERSION_CODES.O)
     @Override
     public void onReceive(Context context, Intent intent) {
         String action = intent.getAction();
@@ -26,7 +30,7 @@ public class NotificationActionReceiver extends BroadcastReceiver {
             dbConn.markAllItemsAsRead();
             EventBus.getDefault().post(new SyncFinishedEvent());
 
-            Integer notificationId = intent.getIntExtra(EXTRA_NOTIFICATION_ID, -1);
+            int notificationId = intent.getIntExtra(EXTRA_NOTIFICATION_ID, -1);
             if (notificationId != -1) {
                 NotificationManager nMgr = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
                 nMgr.cancel(notificationId);
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/OpmlXmlParser.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/OpmlXmlParser.java
index eba5a48b..e6186a96 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/OpmlXmlParser.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/OpmlXmlParser.java
@@ -158,7 +158,7 @@ public class OpmlXmlParser {
 
     // Parses the contents of an entry. If it encounters a title, summary, or link tag, hands them off
     // to their respective "read" methods for processing. Otherwise, skips the tag.
-    private static Entry ReadOutline(XmlPullParser parser) throws XmlPullParserException, IOException {
+    private static Entry ReadOutline(XmlPullParser parser) {
         //parser.require(XmlPullParser.START_TAG, ns, "outline");
 
         String link = parser.getAttributeValue(null, "xmlUrl");
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/PostDelayHandler.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/PostDelayHandler.java
index 4927596a..eb79e422 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/PostDelayHandler.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/PostDelayHandler.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -32,7 +32,7 @@ public class PostDelayHandler {
 
     private static final String TAG = "PostDelayHandler";
     private static Handler handlerTimer;
-    private Context context;
+    private final Context context;
     private static boolean isDelayed = false;
 
     public PostDelayHandler(Context context) {
@@ -67,17 +67,16 @@ public class PostDelayHandler {
         Log.v(TAG, "delay() called with: time = [" + time + "]");
         if(!isDelayed) {
             isDelayed = true;
-            handlerTimer.postDelayed(new Runnable(){
-                public void run() {
-                    isDelayed = false;
-                    Log.v(TAG, "Time exceeded.. Sync state of changed items. Delay was: " + time);
-                    if((!SyncItemStateService.isMyServiceRunning(context)) && NetworkConnection.isNetworkAvailable(context))
-                    {
-                        Log.v(TAG, "Starting SyncItemStateService");
+            handlerTimer.postDelayed(() -> {
+                isDelayed = false;
+                Log.v(TAG, "Time exceeded.. Sync state of changed items. Delay was: " + time);
+                if((!SyncItemStateService.isMyServiceRunning(context)) && NetworkConnection.isNetworkAvailable(context))
+                {
+                    Log.v(TAG, "Starting SyncItemStateService");
 
-                        SyncItemStateService.enqueueWork(context, new Intent());
-                    }
-                }}, time);
+                    SyncItemStateService.enqueueWork(context, new Intent());
+                }
+            }, time);
         }
     }
 }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/SquareRoundedBitmapDisplayer.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/SquareRoundedBitmapDisplayer.java
index 84beb411..62d2f80e 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/SquareRoundedBitmapDisplayer.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/SquareRoundedBitmapDisplayer.java
@@ -46,6 +46,7 @@ public class SquareRoundedBitmapDisplayer implements BitmapProcessor {
 
         // float scaleFactor = (float) width / bitmap.getWidth();
         int side = Math.min(bitmap.getWidth(), bitmap.getHeight());
+        //noinspection SuspiciousNameCombination
         int height = width;
 
          Log.d(TAG, "scale bitmap " + bitmap.getWidth() + "x" + bitmap.getHeight() + " -> " + width + "x" + height);
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ThemeChooser.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ThemeChooser.java
index 6602ed49..23965e43 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ThemeChooser.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ThemeChooser.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -57,6 +57,7 @@ public class ThemeChooser {
             case 0: // Auto (Light / Dark)
                 Log.v(TAG, "Auto (Light / Dark)");
                 if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
+                    //noinspection deprecation
                     defaultNightMode = AppCompatDelegate.MODE_NIGHT_AUTO_TIME;
                 } else { // Android 10+ (Q) supports a system-wide dark mode
                     defaultNightMode = AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM;
@@ -131,6 +132,7 @@ public class ThemeChooser {
                 Log.v(TAG, "MODE_NIGHT_YES (Dark Theme)");
                 return true;
             case AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM:
+                //noinspection deprecation
             case AppCompatDelegate.MODE_NIGHT_AUTO:
                 //Log.v(TAG, "MODE_NIGHT_AUTO");
                 int nightModeFlags = context.getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ThemeUtils.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ThemeUtils.java
index 7c1a77f5..61d2416b 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ThemeUtils.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/helper/ThemeUtils.java
@@ -1,5 +1,5 @@
-/**
- * Android ownCloud News
+/*
+* Android ownCloud News
  *
  * @author David Luhmer
  * @copyright 2019 David Luhmer david-dev@live.de
@@ -33,6 +33,7 @@ import android.widget.SearchView;
 import android.widget.TextView;
 
 import androidx.annotation.ColorInt;
+import androidx.annotation.RequiresApi;
 import androidx.appcompat.widget.ActionMenuView;
 import androidx.appcompat.widget.Toolbar;
 import androidx.core.content.ContextCompat;
@@ -122,6 +123,7 @@ public class ThemeUtils {
      * @param activity
      * @param statusBarColor
      */
+    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
     public static void changeStatusBarColor(Activity activity, @ColorInt int statusBarColor) {
         Window window = activity.getWindow();
         // clear FLAG_TRANSLUCENT_STATUS flag:
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/interfaces/ExpListTextClicked.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/interfaces/ExpListTextClicked.java
index 10a20595..450309f8 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/interfaces/ExpListTextClicked.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/interfaces/ExpListTextClicked.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/AbstractItem.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/AbstractItem.java
index 9b3002b1..9c8c5b3b 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/AbstractItem.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/AbstractItem.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/ConcreteFeedItem.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/ConcreteFeedItem.java
index 24f73a89..645ded1d 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/ConcreteFeedItem.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/ConcreteFeedItem.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/FolderSubscribtionItem.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/FolderSubscribtionItem.java
index 2ed2c580..ab484a0f 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/FolderSubscribtionItem.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/FolderSubscribtionItem.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/NextcloudStatus.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/NextcloudStatus.java
index 0c962a00..eaef20b8 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/NextcloudStatus.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/NextcloudStatus.java
@@ -9,7 +9,7 @@ public class NextcloudStatus {
     public String version;
     public Warnings warnings;
 
-    class Warnings {
+    static class Warnings {
         public String improperlyConfiguredCron;
     }
 }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/Tuple.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/Tuple.java
index 47111459..6f6fc1e6 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/Tuple.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/model/Tuple.java
@@ -1,5 +1,6 @@
 package de.luhmer.owncloudnewsreader.model;
 
+// TODO replace with Pair
 public class Tuple<E, T> {
     public final E key;
     public final T value;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/notification/NextcloudNotificationManager.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/notification/NextcloudNotificationManager.java
index 6bd9e829..8cfa2468 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/notification/NextcloudNotificationManager.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/notification/NextcloudNotificationManager.java
@@ -85,7 +85,8 @@ public class NextcloudNotificationManager {
 
         Intent intentNewsReader = new Intent(context, NewsReaderListActivity.class);
         PendingIntent pIntent = PendingIntent.getActivity(context, 0, intentNewsReader, 0);
-        NotificationCompat.Builder mNotificationDownloadImages = new NotificationCompat.Builder(context, channelId)
+
+        return new NotificationCompat.Builder(context, channelId)
                 .setContentTitle(context.getResources().getString(R.string.app_name))
                 .setContentText(context.getString(R.string.notification_download_images_offline))
                 .setSmallIcon(R.drawable.ic_notification)
@@ -93,8 +94,6 @@ public class NextcloudNotificationManager {
                 .setAutoCancel(true)
                 .setOnlyAlertOnce(true)
                 .setOngoing(true);
-
-        return mNotificationDownloadImages;
     }
 
     public static void showNotificationSaveSingleCachedImageService(Context context, String channelId, File file) {
@@ -118,7 +117,8 @@ public class NextcloudNotificationManager {
 
         Intent intentNewsReader = new Intent(context, NewsReaderListActivity.class);
         PendingIntent pIntent = PendingIntent.getActivity(context, 0, intentNewsReader, 0);
-        NotificationCompat.Builder mNotificationWebPages = new NotificationCompat.Builder(context, channelId)
+
+        return new NotificationCompat.Builder(context, channelId)
                 .setContentTitle(context.getResources().getString(R.string.app_name))
                 .setContentText(context.getString(R.string.notification_download_articles_offline))
                 .setSmallIcon(R.drawable.ic_notification)
@@ -126,8 +126,6 @@ public class NextcloudNotificationManager {
                 .setAutoCancel(true)
                 .setOnlyAlertOnce(true)
                 .setOngoing(true);
-
-        return mNotificationWebPages;
     }
 
 
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/FeedItemTags.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/FeedItemTags.java
index 9eafa476..768d09ec 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/FeedItemTags.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/FeedItemTags.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -29,7 +29,7 @@ public enum FeedItemTags {
 	ALL_STARRED("2"),
 	ALL("3");
 
-	private String segment;
+	private final String segment;
 
 	FeedItemTags(String segment) {
 		this.segment = segment;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/InsertIntoDatabase.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/InsertIntoDatabase.java
index d2f36172..8d42dbe5 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/InsertIntoDatabase.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/InsertIntoDatabase.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/OkHttpImageDownloader.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/OkHttpImageDownloader.java
index b28a1025..8afae922 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/OkHttpImageDownloader.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/OkHttpImageDownloader.java
@@ -15,10 +15,9 @@ import okhttp3.ResponseBody;
 
 public class OkHttpImageDownloader extends BaseImageDownloader {
 
-    @SuppressWarnings("unused")
     private static final String TAG = "OkHttpImageDownloader";
 
-    private OkHttpClient imageClient;
+    private final OkHttpClient imageClient;
 
     public OkHttpImageDownloader(Context context, OkHttpClient imageClient) {
         super(context);
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/OnAsyncTaskCompletedListener.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/OnAsyncTaskCompletedListener.java
index 416a381e..280a4e5d 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/OnAsyncTaskCompletedListener.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/OnAsyncTaskCompletedListener.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/InsertRssItemIntoDatabase.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/InsertRssItemIntoDatabase.java
index 113ed93a..1088e120 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/InsertRssItemIntoDatabase.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/InsertRssItemIntoDatabase.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -138,6 +138,7 @@ class InsertRssItemIntoDatabase {
         }
     }
 
+    @SuppressWarnings("SameParameterValue")
     private static Boolean getBooleanOrDefault(String key, Boolean defaultValue, JsonObject jObj) {
         if(jObj.has(key) && !jObj.get(key).isJsonNull()) {
             return jObj.get(key).getAsBoolean();
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/RssItemObservable.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/RssItemObservable.java
index 9340f494..ff6abef2 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/RssItemObservable.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/reader/nextcloud/RssItemObservable.java
@@ -35,9 +35,9 @@ import okio.BufferedSource;
  */
 public class RssItemObservable implements Publisher<Integer> {
 
-    private DatabaseConnectionOrm mDbConn;
-    private NewsAPI mNewsApi;
-    private SharedPreferences mPrefs;
+    private final DatabaseConnectionOrm mDbConn;
+    private final NewsAPI mNewsApi;
+    private final SharedPreferences mPrefs;
     private static final String TAG = RssItemObservable.class.getCanonicalName();
     private static int maxSizePerSync = 300;
 
@@ -130,7 +130,7 @@ public class RssItemObservable implements Publisher<Integer> {
                     .subscribe(new Observer<RssItem>() {
                         int totalUpdatedUnreadItemCount = 0;
                         final int bufferSize = 150;
-                        List<RssItem> buffer = new ArrayList<>(bufferSize); //Buffer of size X
+                        final List<RssItem> buffer = new ArrayList<>(bufferSize); //Buffer of size X
 
                         @Override
                         public void onSubscribe(@NonNull Disposable d) {
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/DownloadImagesService.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/DownloadImagesService.java
index c6aec03c..ea80835a 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/DownloadImagesService.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/DownloadImagesService.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -34,6 +34,7 @@ import com.nostra13.universalimageloader.core.ImageLoader;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 import java.util.Random;
 
 import de.greenrobot.dao.query.LazyList;
@@ -112,7 +113,7 @@ public class DownloadImagesService extends JobIntentService {
         DatabaseConnectionOrm dbConn = new DatabaseConnectionOrm(this);
         mNotificationDownloadImages = NextcloudNotificationManager.buildNotificationDownloadImageService(this, CHANNEL_ID);
 
-        if(downloadMode.equals(DownloadMode.FAVICONS_ONLY)) {
+        if(Objects.equals(downloadMode, DownloadMode.FAVICONS_ONLY)) {
             List<Feed> feedList = dbConn.getListOfFeeds();
             FavIconHandler favIconHandler = new FavIconHandler(getApplicationContext());
             for(Feed feed : feedList) {
@@ -122,7 +123,7 @@ public class DownloadImagesService extends JobIntentService {
                     Log.e(TAG, ex.getMessage());
                 }
             }
-        } else if(downloadMode.equals(DownloadMode.FAVICONS_AND_PICTURES) || downloadMode.equals(DownloadMode.PICTURES_ONLY)) {
+        } else if(Objects.equals(downloadMode, DownloadMode.FAVICONS_AND_PICTURES) || Objects.equals(downloadMode, DownloadMode.PICTURES_ONLY)) {
             long lastId = intent.getLongExtra(LAST_ITEM_ID, 0);
             List<RssItem> rssItemList = dbConn.getAllItemsWithIdHigher(lastId);
             List<String> links = new ArrayList<>();
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/DownloadWebPageService.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/DownloadWebPageService.java
index 729c19b8..55293b27 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/DownloadWebPageService.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/DownloadWebPageService.java
@@ -127,7 +127,7 @@ public class DownloadWebPageService extends Service {
         }
     }
 
-    private void delayedRunOnMainThread(Runnable runnable, int waitMillis) {
+    private void delayedRunOnMainThread(Runnable runnable, @SuppressWarnings("SameParameterValue") int waitMillis) {
         try {
             Thread.sleep(waitMillis);
             runOnMainThreadAndWait(runnable);
@@ -189,7 +189,7 @@ public class DownloadWebPageService extends Service {
 
     class DownloadWebPage implements Runnable {
 
-        private String url;
+        private final String url;
         private WebView webView;
         private final Object lock;
 
@@ -239,7 +239,7 @@ public class DownloadWebPageService extends Service {
         }
     }
 
-    class DownloadImageWebViewChromeClient extends WebChromeClient {
+    static class DownloadImageWebViewChromeClient extends WebChromeClient {
         @Override
         public boolean onConsoleMessage(ConsoleMessage cm) {
             //Log.d("TAG", cm.message() + " at " + cm.sourceId() + ":" + cm.lineNumber());
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/PodcastDownloadService.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/PodcastDownloadService.java
index 77315462..abafc983 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/PodcastDownloadService.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/PodcastDownloadService.java
@@ -36,7 +36,6 @@ import de.luhmer.owncloudnewsreader.notification.NextcloudNotificationManager;
  */
 public class PodcastDownloadService extends IntentService {
 
-    @SuppressWarnings("unused")
     private static final String TAG = PodcastDownloadService.class.getCanonicalName();
 
     // IntentService can perform, e.g. ACTION_FETCH_NEW_ITEMS
@@ -45,7 +44,7 @@ public class PodcastDownloadService extends IntentService {
     private static final String EXTRA_RECEIVER = "de.luhmer.owncloudnewsreader.services.extra.RECEIVER";
     private static final String EXTRA_URL = "de.luhmer.owncloudnewsreader.services.extra.URL";
 
-    private EventBus eventBus;
+    private final EventBus eventBus;
 
     /**
      * Starts this service to download a podcast. If
@@ -164,7 +163,7 @@ public class PodcastDownloadService extends IntentService {
 
             long startTime = System.nanoTime();
 
-            byte data[] = new byte[1024];
+            byte[] data = new byte[1024];
             long total = 0;
             int count;
             int lastProgress = -1;
@@ -236,7 +235,7 @@ public class PodcastDownloadService extends IntentService {
     //public static final int UPDATE_PROGRESS = 5555;
 
 
-    public class DownloadProgressUpdate {
+    public static class DownloadProgressUpdate {
         public DownloadProgressUpdate(PodcastItem podcast) {
             this.podcast = podcast;
         }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/PodcastPlaybackService.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/PodcastPlaybackService.java
index acd2fe86..3e16256c 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/PodcastPlaybackService.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/PodcastPlaybackService.java
@@ -106,7 +106,7 @@ public class PodcastPlaybackService extends MediaBrowserServiceCompat {
     private PlaybackService mPlaybackService;
     private MediaSessionCompat mSession;
 
-    public static final float PLAYBACK_SPEEDS[] = { 0.25f, 0.5f, 0.75f, 1.0f, 1.25f, 1.5f, 1.75f, 2.0f, 2.5f, 3.0f };
+    public static final float[] PLAYBACK_SPEEDS = { 0.25f, 0.5f, 0.75f, 1.0f, 1.25f, 1.5f, 1.75f, 2.0f, 2.5f, 3.0f };
     private float currentPlaybackSpeed = 1;
 
 
@@ -163,7 +163,7 @@ public class PodcastPlaybackService extends MediaBrowserServiceCompat {
                 mediaItems.add(new MediaBrowserCompat.MediaItem(desc.build(), MediaBrowserCompat.MediaItem.FLAG_BROWSABLE));
             }
         } else {
-            Long feedId = Long.parseLong(s.substring(5));
+            long feedId = Long.parseLong(s.substring(5));
             for (PodcastItem item: dbConn.getListOfAudioPodcastsForFeed(this, feedId)) {
                 MediaDescriptionCompat.Builder desc =
                         new MediaDescriptionCompat.Builder()
@@ -333,7 +333,7 @@ public class PodcastPlaybackService extends MediaBrowserServiceCompat {
     }
     */
 
-    private PlaybackService.PodcastStatusListener podcastStatusListener = new PlaybackService.PodcastStatusListener() {
+    private final PlaybackService.PodcastStatusListener podcastStatusListener = new PlaybackService.PodcastStatusListener() {
         @Override
         public void podcastStatusUpdated() {
             syncMediaAndPlaybackStatus();
@@ -411,7 +411,7 @@ public class PodcastPlaybackService extends MediaBrowserServiceCompat {
     @Subscribe
     public void onEvent(RegisterVideoOutput videoOutput) {
         if(mPlaybackService != null && mPlaybackService instanceof MediaPlayerPlaybackService) {
-            ((MediaPlayerPlaybackService) mPlaybackService).setVideoView(videoOutput.surfaceView, videoOutput.parentResizableView);
+            ((MediaPlayerPlaybackService) mPlaybackService).setVideoView(videoOutput.surfaceView);
         }
     }
 
@@ -471,7 +471,7 @@ public class PodcastPlaybackService extends MediaBrowserServiceCompat {
         audioManager.abandonAudioFocus(audioFocusChangeListener);
     }
 
-    private AudioManager.OnAudioFocusChangeListener audioFocusChangeListener = focusChange -> {
+    private final AudioManager.OnAudioFocusChangeListener audioFocusChangeListener = focusChange -> {
         if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {
             // Permanent loss of audio focus
             // Pause playback immediately
@@ -562,11 +562,7 @@ public class PodcastPlaybackService extends MediaBrowserServiceCompat {
                 .build());
         }
 
-        if(playbackState == PlaybackStateCompat.STATE_PLAYING) {
-            mSession.setActive(true);
-        } else {
-            mSession.setActive(false);
-        }
+        mSession.setActive(playbackState == PlaybackStateCompat.STATE_PLAYING);
 
         podcastNotification.updateStateOfNotification(playbackState, currentPosition, totalDuration);
     }
@@ -769,10 +765,7 @@ public class PodcastPlaybackService extends MediaBrowserServiceCompat {
         List<PodcastItem> audioPodcasts= new ArrayList<>();
         for(PodcastFeedItem podcastFeed : dbConn.getListOfFeedsWithAudioPodcasts()) {
             long id = podcastFeed.mFeed.getId();
-            for(PodcastItem podcastItem : dbConn.getListOfAudioPodcastsForFeed(PodcastPlaybackService.this, id)) {
-
-                audioPodcasts.add(podcastItem);
-            }
+            audioPodcasts.addAll(dbConn.getListOfAudioPodcastsForFeed(PodcastPlaybackService.this, id));
         }
         return audioPodcasts;
     }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/SyncItemStateService.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/SyncItemStateService.java
index e40bb1f3..b435c182 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/SyncItemStateService.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/SyncItemStateService.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -27,6 +27,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.util.Log;
 
+import androidx.annotation.NonNull;
 import androidx.core.app.JobIntentService;
 
 import java.io.IOException;
@@ -62,7 +63,7 @@ public class SyncItemStateService extends JobIntentService {
 	}
 
 	@Override
-	protected void onHandleWork(Intent intent) {
+	protected void onHandleWork(@NonNull Intent intent) {
 		if(mApi.getNewsAPI() == null) {
 			Log.w(TAG, "API is not initialized");
 			return;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/events/SyncFailedEvent.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/events/SyncFailedEvent.java
index 6ae8418e..49ff4941 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/events/SyncFailedEvent.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/events/SyncFailedEvent.java
@@ -5,7 +5,7 @@ package de.luhmer.owncloudnewsreader.services.events;
  */
 public class SyncFailedEvent {
 
-    private Throwable throwable;
+    private final Throwable throwable;
 
     public SyncFailedEvent(Throwable throwable) {
         this.throwable = throwable;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/podcast/MediaPlayerPlaybackService.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/podcast/MediaPlayerPlaybackService.java
index cee05c68..096ce698 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/podcast/MediaPlayerPlaybackService.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/podcast/MediaPlayerPlaybackService.java
@@ -21,7 +21,7 @@ import de.luhmer.owncloudnewsreader.model.PodcastItem;
 
 public class MediaPlayerPlaybackService extends PlaybackService {
     private static final String TAG = MediaPlayerPlaybackService.class.getCanonicalName();
-    private MediaPlayer mMediaPlayer;
+    private final MediaPlayer mMediaPlayer;
     //private View parentView;
 
     public MediaPlayerPlaybackService(final Context context, PodcastStatusListener podcastStatusListener, MediaItem mediaItem) {
@@ -145,7 +145,7 @@ public class MediaPlayerPlaybackService extends PlaybackService {
         return mMediaPlayer.getVideoWidth();
     }
 
-    public void setVideoView(SurfaceView surfaceView, View parentResizableView) {
+    public void setVideoView(SurfaceView surfaceView) {
         if (surfaceView == null) {
             mMediaPlayer.setDisplay(null);
             //Log.v(TAG, "Disable Screen output!");
@@ -166,7 +166,7 @@ public class MediaPlayerPlaybackService extends PlaybackService {
     //private int mSurfaceWidth;
     //private int mSurfaceHeight;
     private SurfaceHolder mSurfaceHolder;
-    private SurfaceHolder.Callback mSHCallback = new SurfaceHolder.Callback() {
+    private final SurfaceHolder.Callback mSHCallback = new SurfaceHolder.Callback() {
         public void surfaceChanged(SurfaceHolder holder, int format, int surfaceWidth, int surfaceHeight) {
             Log.v(TAG, "surfaceChanged() called with: holder = [" + holder + "], format = [" + format + "], surfaceWidth = [" + surfaceWidth + "], surfaceHeight = [" + surfaceHeight + "]");
             //mSurfaceWidth = surfaceWidth;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/podcast/PlaybackService.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/podcast/PlaybackService.java
index 48d2b67c..031c5edc 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/podcast/PlaybackService.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/services/podcast/PlaybackService.java
@@ -13,8 +13,8 @@ public abstract class PlaybackService {
     public enum VideoType { None, Video, VideoType, YouTube }
 
     private @PlaybackStateCompat.State int mStatus = PlaybackStateCompat.STATE_NONE;
-    private PodcastStatusListener podcastStatusListener;
-    private MediaItem mediaItem;
+    private final PodcastStatusListener podcastStatusListener;
+    private final MediaItem mediaItem;
 
     public interface PodcastStatusListener {
         void podcastStatusUpdated();
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/MemorizingDialogFragment.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/MemorizingDialogFragment.java
index 2b77d0d5..bfc4c394 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/MemorizingDialogFragment.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/MemorizingDialogFragment.java
@@ -32,6 +32,7 @@ import android.content.Intent;
 import android.os.Bundle;
 import android.util.Log;
 
+import androidx.annotation.NonNull;
 import androidx.appcompat.app.AlertDialog;
 import androidx.fragment.app.DialogFragment;
 import de.luhmer.owncloudnewsreader.R;
@@ -51,11 +52,11 @@ public class MemorizingDialogFragment extends DialogFragment
 	@Override
 	public void onCreate(Bundle savedInstanceState) {
 		Log.d(TAG, "onCreate");
-        Bundle i = getArguments();
+        Bundle args = requireArguments();
 
-        app = i.getString(MemorizingTrustManager.DECISION_INTENT_APP);
-        decisionId = i.getInt(MemorizingTrustManager.DECISION_INTENT_ID, MTMDecision.DECISION_INVALID);
-        cert = i.getString(MemorizingTrustManager.DECISION_INTENT_CERT);
+        app = args.getString(MemorizingTrustManager.DECISION_INTENT_APP);
+        decisionId = args.getInt(MemorizingTrustManager.DECISION_INTENT_ID, MTMDecision.DECISION_INVALID);
+        cert = args.getString(MemorizingTrustManager.DECISION_INTENT_CERT);
         //Log.d(TAG, "onResume with " + i.getExtras() + " decId=" + decisionId);
         //Log.d(TAG, "data: " + i.getData());
 
@@ -66,7 +67,7 @@ public class MemorizingDialogFragment extends DialogFragment
 	public void onResume() {
 		super.onResume();
 		
-		new AlertDialog.Builder(getActivity()).setTitle(R.string.mtm_accept_cert)
+		new AlertDialog.Builder(requireContext()).setTitle(R.string.mtm_accept_cert)
 			.setMessage(cert)
 			.setPositiveButton(R.string.mtm_decision_always, this)
 			.setNegativeButton(R.string.mtm_decision_abort, this)
@@ -79,9 +80,9 @@ public class MemorizingDialogFragment extends DialogFragment
 		Intent i = new Intent(MemorizingTrustManager.DECISION_INTENT + "/" + app);
 		i.putExtra(MemorizingTrustManager.DECISION_INTENT_ID, decisionId);
 		i.putExtra(MemorizingTrustManager.DECISION_INTENT_CHOICE, decision);
-		getActivity().sendBroadcast(i);
+		requireActivity().sendBroadcast(i);
 		//finish();
-		getDialog().dismiss();
+		requireDialog().dismiss();
 	}
 
 	// react on AlertDialog button press
@@ -101,7 +102,7 @@ public class MemorizingDialogFragment extends DialogFragment
 		sendDecision(decision);
 	}
 
-	public void onCancel(DialogInterface dialog) {
+	public void onCancel(@NonNull DialogInterface dialog) {
 		sendDecision(MTMDecision.DECISION_ABORT);
 	}
 }
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/MemorizingTrustManager.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/MemorizingTrustManager.java
index 8f6e2192..1efaa34f 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/MemorizingTrustManager.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/MemorizingTrustManager.java
@@ -44,6 +44,10 @@ import android.os.Handler;
 import android.util.Log;
 import android.util.SparseArray;
 
+import androidx.core.app.NotificationCompat;
+import androidx.fragment.app.DialogFragment;
+import androidx.fragment.app.FragmentActivity;
+
 import java.io.File;
 import java.io.IOException;
 import java.lang.ref.WeakReference;
@@ -61,9 +65,6 @@ import javax.net.ssl.TrustManager;
 import javax.net.ssl.TrustManagerFactory;
 import javax.net.ssl.X509TrustManager;
 
-import androidx.core.app.NotificationCompat;
-import androidx.fragment.app.DialogFragment;
-import androidx.fragment.app.FragmentActivity;
 import de.luhmer.owncloudnewsreader.R;
 
 /**
@@ -94,11 +95,11 @@ public class MemorizingTrustManager implements X509TrustManager {
 	private static final SparseArray<MTMDecision> openDecisions = new SparseArray<>();
 
 	Handler masterHandler;
-	private File keyStoreFile;
-	private KeyStore appKeyStore;
-	private X509TrustManager defaultTrustManager;
+	private final File keyStoreFile;
+	private final KeyStore appKeyStore;
+	private final X509TrustManager defaultTrustManager;
 	private X509TrustManager appTrustManager;
-	private Context mContext;
+	private final Context mContext;
 	
 	/** Creates an instance of the MemorizingTrustManager class.
 	 *
@@ -496,24 +497,22 @@ public class MemorizingTrustManager implements X509TrustManager {
 			public void onReceive(Context ctx, Intent i) { interactResult(i); }
 		};
 		mContext.registerReceiver(decisionReceiver, new IntentFilter(DECISION_INTENT + "/" + mContext.getPackageName()));
-		masterHandler.post(new Runnable() {
-			public void run() {
-				Intent ni = new Intent(mContext, MemorizingDialogFragment.class);
-				ni.setData(Uri.parse(MemorizingTrustManager.class.getName() + "/" + myId));
-
-                Bundle bundle = new Bundle();
-                bundle.putString(DECISION_INTENT_APP, mContext.getPackageName());
-                bundle.putInt(DECISION_INTENT_ID, myId);
-                bundle.putString(DECISION_INTENT_CERT, certMessage);
-				
-				DialogFragment dialog = new MemorizingDialogFragment();
-                dialog.setArguments(bundle);
-				try {
-					dialog.show(((FragmentActivity) getUI()).getSupportFragmentManager(), "NoticeDialogFragment");
-				} catch(Exception ex) {
-					Log.e(TAG, "startActivity: " + ex);
-					startActivityNotification(ni, certMessage);					
-				}
+		masterHandler.post(() -> {
+			Intent ni = new Intent(mContext, MemorizingDialogFragment.class);
+			ni.setData(Uri.parse(MemorizingTrustManager.class.getName() + "/" + myId));
+
+			Bundle bundle = new Bundle();
+			bundle.putString(DECISION_INTENT_APP, mContext.getPackageName());
+			bundle.putInt(DECISION_INTENT_ID, myId);
+			bundle.putString(DECISION_INTENT_CERT, certMessage);
+
+			DialogFragment dialog = new MemorizingDialogFragment();
+			dialog.setArguments(bundle);
+			try {
+				dialog.show(((FragmentActivity) getUI()).getSupportFragmentManager(), "NoticeDialogFragment");
+			} catch (Exception ex) {
+				Log.e(TAG, "startActivity: " + ex);
+				startActivityNotification(ni, certMessage);
 			}
 		});
 
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/OkHttpSSLClient.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/OkHttpSSLClient.java
index d28af577..36f1aac8 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/OkHttpSSLClient.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/OkHttpSSLClient.java
@@ -4,6 +4,8 @@ import android.annotation.SuppressLint;
 import android.content.SharedPreferences;
 import android.os.Build;
 
+import androidx.annotation.NonNull;
+
 import com.google.gson.JsonParseException;
 
 import java.io.IOException;
@@ -123,6 +125,7 @@ public class OkHttpSSLClient {
             this.mCredentials = credentials;
         }
 
+        @NonNull
         @Override
         public Response intercept(Chain chain) throws IOException {
             Request request = chain.request();
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/TLSSocketFactory.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/TLSSocketFactory.java
index f50f6f76..7e111b44 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/TLSSocketFactory.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/ssl/TLSSocketFactory.java
@@ -60,19 +60,19 @@ public class TLSSocketFactory extends SSLSocketFactory {
 
     //NoTLS
     @Override
-    public Socket createSocket(String s, int i) throws IOException {
+    public Socket createSocket(String s, int i) {
         return null;
     }
     @Override
-    public Socket createSocket(String s, int i, InetAddress inetAddress, int i2) throws IOException {
+    public Socket createSocket(String s, int i, InetAddress inetAddress, int i2) {
         return null;
     }
     @Override
-    public Socket createSocket(InetAddress inetAddress, int i) throws IOException {
+    public Socket createSocket(InetAddress inetAddress, int i) {
         return null;
     }
     @Override
-    public Socket createSocket(InetAddress inetAddress, int i, InetAddress inetAddress2, int i2) throws IOException {
+    public Socket createSocket(InetAddress inetAddress, int i, InetAddress inetAddress2, int i2) {
         return null;
     }
 
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/AnimatingProgressBar.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/AnimatingProgressBar.java
index fd8e7398..22256b7e 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/AnimatingProgressBar.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/AnimatingProgressBar.java
@@ -85,13 +85,7 @@ public class AnimatingProgressBar extends ProgressBar {
             animator = ValueAnimator.ofInt(getProgress() * RESOLUTION, progress * RESOLUTION);
             animator.setInterpolator(DEFAULT_INTERPOLATOR);
             animator.setDuration(ANIMATION_DURATION);
-            animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
-
-                @Override
-                public void onAnimationUpdate(ValueAnimator animation) {
-                    AnimatingProgressBar.super.setProgress((Integer) animation.getAnimatedValue());
-                }
-            });
+            animator.addUpdateListener(animation -> AnimatingProgressBar.super.setProgress((Integer) animation.getAnimatedValue()));
         }
 
         animator.cancel();
@@ -110,13 +104,7 @@ public class AnimatingProgressBar extends ProgressBar {
             animatorSecondary = ValueAnimator.ofInt(getSecondaryProgress() * RESOLUTION, secondaryProgress * RESOLUTION);
             animatorSecondary.setInterpolator(DEFAULT_INTERPOLATOR);
             animatorSecondary.setDuration(ANIMATION_DURATION);
-            animatorSecondary.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
-
-                @Override
-                public void onAnimationUpdate(ValueAnimator animation) {
-                    AnimatingProgressBar.super.setSecondaryProgress((Integer) animation.getAnimatedValue());
-                }
-            });
+            animatorSecondary.addUpdateListener(animation -> AnimatingProgressBar.super.setSecondaryProgress((Integer) animation.getAnimatedValue()));
         }
 
         animatorSecondary.cancel();
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/PodcastNotification.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/PodcastNotification.java
index 8277e13d..3493d2f2 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/PodcastNotification.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/PodcastNotification.java
@@ -29,7 +29,7 @@ public class PodcastNotification {
     private NotificationCompat.Builder notificationBuilder;
     private final String CHANNEL_ID = "Podcast Notification";
 
-    private MediaSessionCompat mSession;
+    private final MediaSessionCompat mSession;
     private @PlaybackStateCompat.State int lastStatus = PlaybackStateCompat.STATE_NONE;
 
     public final static int NOTIFICATION_ID = 1111;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/PodcastSlidingUpPanelLayout.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/PodcastSlidingUpPanelLayout.java
index e2437064..85c83db7 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/PodcastSlidingUpPanelLayout.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/view/PodcastSlidingUpPanelLayout.java
@@ -65,8 +65,7 @@ public class PodcastSlidingUpPanelLayout extends SlidingUpPanelLayout {
 
         v.getLayoutParams().height = 0;
         v.setVisibility(View.VISIBLE);
-        Animation a = new Animation()
-        {
+        Animation a = new Animation() {
             @Override
             protected void applyTransformation(float interpolatedTime, Transformation t) {
                 v.getLayoutParams().height = interpolatedTime == 1
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetNewsViewsFactory.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetNewsViewsFactory.java
index 6c7a1218..e67d6a9f 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetNewsViewsFactory.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetNewsViewsFactory.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -48,9 +48,9 @@ public class WidgetNewsViewsFactory implements RemoteViewsService.RemoteViewsFac
 
     private DatabaseConnectionOrm dbConn;
     private LazyList<RssItem> rssItems;
-	private Context context;
+	private final Context context;
 
-	private int appWidgetId;
+	private final int appWidgetId;
 
 	public WidgetNewsViewsFactory(Context context, Intent intent) {
 		this.context = context;
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetProvider.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetProvider.java
index 40f1b892..9df84b7a 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetProvider.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetProvider.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer
@@ -60,7 +60,7 @@ public class WidgetProvider extends AppWidgetProvider {
 
 
     public static void UpdateWidget(Context context) {
-        int ids[] = AppWidgetManager.getInstance(context).getAppWidgetIds(new ComponentName(context, WidgetProvider.class));
+        int[] ids = AppWidgetManager.getInstance(context).getAppWidgetIds(new ComponentName(context, WidgetProvider.class));
 
         for(int appWidgetId : ids) {
             AppWidgetManager.getInstance(context).notifyAppWidgetViewDataChanged(appWidgetId, R.id.list_view);
@@ -83,7 +83,7 @@ public class WidgetProvider extends AppWidgetProvider {
     public void onReceive(Context context, Intent intent) {
         inject(context);
 
-    	final int appWidgetId[];
+    	final int[] appWidgetId;
         if(intent.hasExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS))
             appWidgetId = intent.getIntArrayExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS);
     	else if(intent.hasExtra(AppWidgetManager.EXTRA_APPWIDGET_ID))
@@ -111,7 +111,7 @@ public class WidgetProvider extends AppWidgetProvider {
 
             } */ else if (action.equals(ACTION_LIST_CLICK)) {
                 try {
-                    Long rssItemId = intent.getExtras().getLong(RSS_ITEM_ID);
+                    long rssItemId = intent.getExtras().getLong(RSS_ITEM_ID);
 
 
                     if (intent.hasExtra(ACTION_CHECKED_CLICK)) {
diff --git a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetService.java b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetService.java
index 84f3e63e..0bc6fb62 100644
--- a/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetService.java
+++ b/News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/widget/WidgetService.java
@@ -1,4 +1,4 @@
-/**
+/*
 * Android ownCloud News
 *
 * @author David Luhmer