1 files changed, 162 insertions, 0 deletions
diff --git a/mail/src/main/java/org/spongycastle/mail/smime/util/FileBackedMimeBodyPart.java b/mail/src/main/java/org/spongycastle/mail/smime/util/FileBackedMimeBodyPart.java
new file mode 100644
index 00000000..6bae91c9
--- /dev/null
+++ b/mail/src/main/java/org/spongycastle/mail/smime/util/FileBackedMimeBodyPart.java
@@ -0,0 +1,162 @@
+package org.bouncycastle.mail.smime.util;
+
+import javax.mail.MessagingException;
+import javax.mail.internet.InternetHeaders;
+import javax.mail.internet.MimeBodyPart;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Enumeration;
+
+public class FileBackedMimeBodyPart 
+    extends MimeBodyPart
+{
+    private static final int BUF_SIZE = 32760;
+
+    private final File _file;
+
+    /**
+     * Create a MimeBodyPart backed by the data in file.
+     *
+     * @param file file containing the body part.
+     * @throws MessagingException an exception occurs parsing file.
+     * @throws IOException an exception occurs accessing file.
+     */
+    public FileBackedMimeBodyPart(
+        File file)
+        throws MessagingException, IOException
+    {
+        super(new SharedFileInputStream(file));
+
+        _file = file;
+    }
+
+    /**
+     * Create a MimeBodyPart backed by file based on the headers and
+     * content data in content.
+     *
+     * @param content an inputstream containing the body part.
+     * @param file a handle to the backing file to use for storage.
+     * @throws MessagingException an exception occurs parsing the resulting body part in file.
+     * @throws IOException an exception occurs accessing file or content.
+     */
+    public FileBackedMimeBodyPart(
+        InputStream content,
+        File file)
+        throws MessagingException, IOException
+    {
+        this(saveStreamToFile(content, file));
+    }
+
+    /**
+     * Create a MimeBodyPart backed by file, with the headers
+     * given in headers and body content taken from the stream body.
+     *
+     * @param headers headers for the body part.
+     * @param body internal content for the body part.
+     * @param file backing file to use.
+     *
+     * @throws MessagingException if the body part can't be produced.
+     * @throws IOException if there is an issue reading stream or writing to file.
+     */
+    public FileBackedMimeBodyPart(
+        InternetHeaders headers,
+        InputStream body,
+        File file)
+        throws MessagingException, IOException
+    {
+        this(saveStreamToFile(headers, body, file));
+    }
+
+    public void writeTo(
+        OutputStream out)
+        throws IOException, MessagingException
+    {
+        if (!_file.exists())
+        {
+            throw new IOException("file " + _file.getCanonicalPath() + " no longer exists.");
+        }
+
+        super.writeTo(out);
+    }
+
+    /**
+     * Close off the underlying shared streams and remove the backing file.
+     *
+     * @throws IOException if streams cannot be closed or the file cannot be deleted.
+     */
+    public void dispose() 
+        throws IOException
+    {
+        ((SharedFileInputStream)contentStream).getRoot().dispose();
+        
+        if (_file.exists() && !_file.delete())
+        {
+            throw new IOException("deletion of underlying file <" + _file.getCanonicalPath() + "> failed.");
+        }
+    }
+
+    private static File saveStreamToFile(InputStream content, File tempFile)
+        throws IOException
+    {
+        saveContentToStream(new FileOutputStream(tempFile), content);
+
+        return tempFile;
+    }
+
+    private static File saveStreamToFile(InternetHeaders headers, InputStream content, File tempFile)
+        throws IOException
+    {
+        OutputStream out = new FileOutputStream(tempFile);
+        Enumeration en = headers.getAllHeaderLines();
+
+        while (en.hasMoreElements())
+        {
+            writeHeader(out, (String)en.nextElement());
+        }
+
+        writeSeperator(out);
+
+        saveContentToStream(out, content);
+
+        return tempFile;
+    }
+
+
+    private static void writeHeader(OutputStream out, String header)
+        throws IOException
+    {
+        for (int i = 0; i != header.length(); i++)
+        {
+            out.write(header.charAt(i));
+        }
+
+        writeSeperator(out);
+    }
+
+     private static void writeSeperator(OutputStream out)
+         throws IOException
+     {
+         out.write('\r');
+         out.write('\n');
+     }
+
+     private static void saveContentToStream(
+        OutputStream out,
+        InputStream content)
+        throws IOException
+    {
+        byte[] buf = new byte[BUF_SIZE];
+        int    len;
+
+        while ((len = content.read(buf, 0, buf.length)) > 0)
+        {
+            out.write(buf, 0, len);
+        }
+
+        out.close();
+        content.close();
+    }
+ }