diff options
Diffstat (limited to 'openjdk/java/lang/ClassLoader.java')
| -rw-r--r-- | openjdk/java/lang/ClassLoader.java | 2261 |
1 files changed, 0 insertions, 2261 deletions
diff --git a/openjdk/java/lang/ClassLoader.java b/openjdk/java/lang/ClassLoader.java deleted file mode 100644 index 57c1ee3e..00000000 --- a/openjdk/java/lang/ClassLoader.java +++ /dev/null @@ -1,2261 +0,0 @@ -/* - * Copyright (c) 1994, 2011, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. Oracle designates this - * particular file as subject to the "Classpath" exception as provided - * by Oracle in the LICENSE file that accompanied this code. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - */ -package java.lang; - -import java.io.InputStream; -import java.io.IOException; -import java.io.File; -import java.lang.reflect.Constructor; -import java.lang.reflect.InvocationTargetException; -import java.net.MalformedURLException; -import java.net.URL; -import java.security.AccessController; -import java.security.AccessControlContext; -import java.security.CodeSource; -import java.security.Policy; -import java.security.PrivilegedAction; -import java.security.PrivilegedActionException; -import java.security.PrivilegedExceptionAction; -import java.security.ProtectionDomain; -import java.security.cert.Certificate; -import java.util.Collections; -import java.util.Enumeration; -import java.util.HashMap; -import java.util.HashSet; -import java.util.Set; -import java.util.Stack; -import java.util.Map; -import java.util.Vector; -import java.util.Hashtable; -import java.util.WeakHashMap; -import java.util.concurrent.ConcurrentHashMap; -import sun.misc.ClassFileTransformer; -import sun.misc.CompoundEnumeration; -import sun.misc.Resource; -import sun.misc.URLClassPath; -import sun.misc.VM; -import sun.reflect.CallerSensitive; -import sun.reflect.Reflection; -import sun.security.util.SecurityConstants; - -/** - * A class loader is an object that is responsible for loading classes. The - * class <tt>ClassLoader</tt> is an abstract class. Given the <a - * href="#name">binary name</a> of a class, a class loader should attempt to - * locate or generate data that constitutes a definition for the class. A - * typical strategy is to transform the name into a file name and then read a - * "class file" of that name from a file system. - * - * <p> Every {@link Class <tt>Class</tt>} object contains a {@link - * Class#getClassLoader() reference} to the <tt>ClassLoader</tt> that defined - * it. - * - * <p> <tt>Class</tt> objects for array classes are not created by class - * loaders, but are created automatically as required by the Java runtime. - * The class loader for an array class, as returned by {@link - * Class#getClassLoader()} is the same as the class loader for its element - * type; if the element type is a primitive type, then the array class has no - * class loader. - * - * <p> Applications implement subclasses of <tt>ClassLoader</tt> in order to - * extend the manner in which the Java virtual machine dynamically loads - * classes. - * - * <p> Class loaders may typically be used by security managers to indicate - * security domains. - * - * <p> The <tt>ClassLoader</tt> class uses a delegation model to search for - * classes and resources. Each instance of <tt>ClassLoader</tt> has an - * associated parent class loader. When requested to find a class or - * resource, a <tt>ClassLoader</tt> instance will delegate the search for the - * class or resource to its parent class loader before attempting to find the - * class or resource itself. The virtual machine's built-in class loader, - * called the "bootstrap class loader", does not itself have a parent but may - * serve as the parent of a <tt>ClassLoader</tt> instance. - * - * <p> Class loaders that support concurrent loading of classes are known as - * <em>parallel capable</em> class loaders and are required to register - * themselves at their class initialization time by invoking the - * {@link - * #registerAsParallelCapable <tt>ClassLoader.registerAsParallelCapable</tt>} - * method. Note that the <tt>ClassLoader</tt> class is registered as parallel - * capable by default. However, its subclasses still need to register themselves - * if they are parallel capable. <br> - * In environments in which the delegation model is not strictly - * hierarchical, class loaders need to be parallel capable, otherwise class - * loading can lead to deadlocks because the loader lock is held for the - * duration of the class loading process (see {@link #loadClass - * <tt>loadClass</tt>} methods). - * - * <p> Normally, the Java virtual machine loads classes from the local file - * system in a platform-dependent manner. For example, on UNIX systems, the - * virtual machine loads classes from the directory defined by the - * <tt>CLASSPATH</tt> environment variable. - * - * <p> However, some classes may not originate from a file; they may originate - * from other sources, such as the network, or they could be constructed by an - * application. The method {@link #defineClass(String, byte[], int, int) - * <tt>defineClass</tt>} converts an array of bytes into an instance of class - * <tt>Class</tt>. Instances of this newly defined class can be created using - * {@link Class#newInstance <tt>Class.newInstance</tt>}. - * - * <p> The methods and constructors of objects created by a class loader may - * reference other classes. To determine the class(es) referred to, the Java - * virtual machine invokes the {@link #loadClass <tt>loadClass</tt>} method of - * the class loader that originally created the class. - * - * <p> For example, an application could create a network class loader to - * download class files from a server. Sample code might look like: - * - * <blockquote><pre> - * ClassLoader loader = new NetworkClassLoader(host, port); - * Object main = loader.loadClass("Main", true).newInstance(); - * . . . - * </pre></blockquote> - * - * <p> The network class loader subclass must define the methods {@link - * #findClass <tt>findClass</tt>} and <tt>loadClassData</tt> to load a class - * from the network. Once it has downloaded the bytes that make up the class, - * it should use the method {@link #defineClass <tt>defineClass</tt>} to - * create a class instance. A sample implementation is: - * - * <blockquote><pre> - * class NetworkClassLoader extends ClassLoader { - * String host; - * int port; - * - * public Class findClass(String name) { - * byte[] b = loadClassData(name); - * return defineClass(name, b, 0, b.length); - * } - * - * private byte[] loadClassData(String name) { - * // load the class data from the connection - * . . . - * } - * } - * </pre></blockquote> - * - * <h4> <a name="name">Binary names</a> </h4> - * - * <p> Any class name provided as a {@link String} parameter to methods in - * <tt>ClassLoader</tt> must be a binary name as defined by - * <cite>The Java™ Language Specification</cite>. - * - * <p> Examples of valid class names include: - * <blockquote><pre> - * "java.lang.String" - * "javax.swing.JSpinner$DefaultEditor" - * "java.security.KeyStore$Builder$FileBuilder$1" - * "java.net.URLClassLoader$3$1" - * </pre></blockquote> - * - * @see #resolveClass(Class) - * @since 1.0 - */ -public abstract class ClassLoader { - - // If initialization succeed this is set to true and security checks will - // succeed. Otherwise the object is not initialized and the object is - // useless. - private final boolean initialized; - - // The parent class loader for delegation - // Note: VM hardcoded the offset of this field, thus all new fields - // must be added *after* it. - private final ClassLoader parent; - - /** - * Encapsulates the set of parallel capable loader types. - */ - private static class ParallelLoaders { - private ParallelLoaders() {} - - // the set of parallel capable loader types - private static final Set<Class<? extends ClassLoader>> loaderTypes = - Collections.newSetFromMap( - new WeakHashMap<Class<? extends ClassLoader>, Boolean>()); - static { - synchronized (loaderTypes) { loaderTypes.add(ClassLoader.class); } - } - - /** - * Registers the given class loader type as parallel capabale. - * Returns {@code true} is successfully registered; {@code false} if - * loader's super class is not registered. - */ - static boolean register(Class<? extends ClassLoader> c) { - synchronized (loaderTypes) { - if (loaderTypes.contains(c.getSuperclass())) { - // register the class loader as parallel capable - // if and only if all of its super classes are. - // Note: given current classloading sequence, if - // the immediate super class is parallel capable, - // all the super classes higher up must be too. - loaderTypes.add(c); - return true; - } else { - return false; - } - } - } - - /** - * Returns {@code true} if the given class loader type is - * registered as parallel capable. - */ - static boolean isRegistered(Class<? extends ClassLoader> c) { - synchronized (loaderTypes) { - return loaderTypes.contains(c); - } - } - } - - // Maps class name to the corresponding lock object when the current - // class loader is parallel capable. - // Note: VM also uses this field to decide if the current class loader - // is parallel capable and the appropriate lock object for class loading. - private final ConcurrentHashMap<String, Object> parallelLockMap; - - // Hashtable that maps packages to certs - private final Map <String, Certificate[]> package2certs; - - // Shared among all packages with unsigned classes - private static final Certificate[] nocerts = new Certificate[0]; - - // The classes loaded by this class loader. The only purpose of this table - // is to keep the classes from being GC'ed until the loader is GC'ed. - private final Vector<Class<?>> classes = new Vector<>(); - - // The "default" domain. Set as the default ProtectionDomain on newly - // created classes. - private final ProtectionDomain defaultDomain = - new ProtectionDomain(new CodeSource(null, (Certificate[]) null), - null, this, null); - - // The initiating protection domains for all classes loaded by this loader - private final Set<ProtectionDomain> domains; - - // Invoked by the VM to record every loaded class with this loader. - void addClass(Class c) { - classes.addElement(c); - } - - // The packages defined in this class loader. Each package name is mapped - // to its corresponding Package object. - // @GuardedBy("itself") - private final HashMap<String, Package> packages = new HashMap<>(); - - @ikvm.lang.Internal - public static final ClassLoader DUMMY = new ClassLoader(false) { }; - - ClassLoader(boolean ignored) - { - // [IKVM] This constructor is IKVM specific and only used to construct DUMMY. - // Note that this body is replaced in map.xml with an empty body as - // we don't want to execute any of the instance field initializers. - this((Void)null, (ClassLoader)null); - } - - private static Void checkCreateClassLoader() { - SecurityManager security = System.getSecurityManager(); - if (security != null) { - security.checkCreateClassLoader(); - } - return null; - } - - // [IKVM] this normally private constructor is also used by ikvm.runtime.AssemblyClassLoader - // to construct an assembly class loader without doing a security check - @ikvm.lang.Internal - protected ClassLoader(Void unused, ClassLoader parent) { - if (parent != null) { - parent.check(); - } - this.parent = parent; - if (ParallelLoaders.isRegistered(this.getClass())) { - parallelLockMap = new ConcurrentHashMap<>(); - package2certs = new ConcurrentHashMap<>(); - domains = - Collections.synchronizedSet(new HashSet<ProtectionDomain>()); - assertionLock = new Object(); - } else { - // no finer-grained lock; lock on the classloader instance - parallelLockMap = null; - package2certs = new Hashtable<>(); - domains = new HashSet<>(); - assertionLock = this; - } - initialized = true; - } - - /** - * Creates a new class loader using the specified parent class loader for - * delegation. - * - * <p> If there is a security manager, its {@link - * SecurityManager#checkCreateClassLoader() - * <tt>checkCreateClassLoader</tt>} method is invoked. This may result in - * a security exception. </p> - * - * @param parent - * The parent class loader - * - * @throws SecurityException - * If a security manager exists and its - * <tt>checkCreateClassLoader</tt> method doesn't allow creation - * of a new class loader. - * - * @since 1.2 - */ - protected ClassLoader(ClassLoader parent) { - this(checkCreateClassLoader(), parent); - } - - /** - * Creates a new class loader using the <tt>ClassLoader</tt> returned by - * the method {@link #getSystemClassLoader() - * <tt>getSystemClassLoader()</tt>} as the parent class loader. - * - * <p> If there is a security manager, its {@link - * SecurityManager#checkCreateClassLoader() - * <tt>checkCreateClassLoader</tt>} method is invoked. This may result in - * a security exception. </p> - * - * @throws SecurityException - * If a security manager exists and its - * <tt>checkCreateClassLoader</tt> method doesn't allow creation - * of a new class loader. - */ - protected ClassLoader() { - this(checkCreateClassLoader(), getSystemClassLoader()); - } - - // -- Class -- - - /** - * Loads the class with the specified <a href="#name">binary name</a>. - * This method searches for classes in the same manner as the {@link - * #loadClass(String, boolean)} method. It is invoked by the Java virtual - * machine to resolve class references. Invoking this method is equivalent - * to invoking {@link #loadClass(String, boolean) <tt>loadClass(name, - * false)</tt>}. </p> - * - * @param name - * The <a href="#name">binary name</a> of the class - * - * @return The resulting <tt>Class</tt> object - * - * @throws ClassNotFoundException - * If the class was not found - */ - public Class<?> loadClass(String name) throws ClassNotFoundException { - return loadClass(name, false); - } - - /** - * Loads the class with the specified <a href="#name">binary name</a>. The - * default implementation of this method searches for classes in the - * following order: - * - * <p><ol> - * - * <li><p> Invoke {@link #findLoadedClass(String)} to check if the class - * has already been loaded. </p></li> - * - * <li><p> Invoke the {@link #loadClass(String) <tt>loadClass</tt>} method - * on the parent class loader. If the parent is <tt>null</tt> the class - * loader built-in to the virtual machine is used, instead. </p></li> - * - * <li><p> Invoke the {@link #findClass(String)} method to find the - * class. </p></li> - * - * </ol> - * - * <p> If the class was found using the above steps, and the - * <tt>resolve</tt> flag is true, this method will then invoke the {@link - * #resolveClass(Class)} method on the resulting <tt>Class</tt> object. - * - * <p> Subclasses of <tt>ClassLoader</tt> are encouraged to override {@link - * #findClass(String)}, rather than this method. </p> - * - * <p> Unless overridden, this method synchronizes on the result of - * {@link #getClassLoadingLock <tt>getClassLoadingLock</tt>} method - * during the entire class loading process. - * - * @param name - * The <a href="#name">binary name</a> of the class - * - * @param resolve - * If <tt>true</tt> then resolve the class - * - * @return The resulting <tt>Class</tt> object - * - * @throws ClassNotFoundException - * If the class could not be found - */ - protected Class<?> loadClass(String name, boolean resolve) - throws ClassNotFoundException - { - synchronized (getClassLoadingLock(name)) { - // First, check if the class has already been loaded - Class c = findLoadedClass(name); - if (c == null) { - try { - if (parent != null) { - c = parent.loadClass(name, false); - } else { - c = findBootstrapClassOrNull(name); - } - } catch (ClassNotFoundException e) { - // ClassNotFoundException thrown if class not found - // from the non-null parent class loader - } - - if (c == null) { - // If still not found, then invoke findClass in order - // to find the class. - c = findClass(name); - } - } - if (resolve) { - resolveClass(c); - } - return c; - } - } - - /** - * Returns the lock object for class loading operations. - * For backward compatibility, the default implementation of this method - * behaves as follows. If this ClassLoader object is registered as - * parallel capable, the method returns a dedicated object associated - * with the specified class name. Otherwise, the method returns this - * ClassLoader object. </p> - * - * @param className - * The name of the to-be-loaded class - * - * @return the lock for class loading operations - * - * @throws NullPointerException - * If registered as parallel capable and <tt>className</tt> is null - * - * @see #loadClass(String, boolean) - * - * @since 1.7 - */ - protected Object getClassLoadingLock(String className) { - Object lock = this; - if (parallelLockMap != null) { - Object newLock = new Object(); - lock = parallelLockMap.putIfAbsent(className, newLock); - if (lock == null) { - lock = newLock; - } - } - return lock; - } - - // This method is invoked by the virtual machine to load a class. - final Class loadClassInternal(String name) - throws ClassNotFoundException - { - // For backward compatibility, explicitly lock on 'this' when - // the current class loader is not parallel capable. - if (parallelLockMap == null) { - synchronized (this) { - return loadClass(name); - } - } else { - return loadClass(name); - } - } - - // Invoked by the VM after loading class with this loader. - final void checkPackageAccess(Class cls, ProtectionDomain pd) { - final SecurityManager sm = System.getSecurityManager(); - if (sm != null) { - final String name = cls.getName(); - final int i = name.lastIndexOf('.'); - if (i != -1) { - AccessController.doPrivileged(new PrivilegedAction<Void>() { - public Void run() { - sm.checkPackageAccess(name.substring(0, i)); - return null; - } - }, new AccessControlContext(new ProtectionDomain[] {pd})); - } - } - domains.add(pd); - } - - /** - * Finds the class with the specified <a href="#name">binary name</a>. - * This method should be overridden by class loader implementations that - * follow the delegation model for loading classes, and will be invoked by - * the {@link #loadClass <tt>loadClass</tt>} method after checking the - * parent class loader for the requested class. The default implementation - * throws a <tt>ClassNotFoundException</tt>. </p> - * - * @param name - * The <a href="#name">binary name</a> of the class - * - * @return The resulting <tt>Class</tt> object - * - * @throws ClassNotFoundException - * If the class could not be found - * - * @since 1.2 - */ - protected Class<?> findClass(String name) throws ClassNotFoundException { - throw new ClassNotFoundException(name); - } - - /** - * Converts an array of bytes into an instance of class <tt>Class</tt>. - * Before the <tt>Class</tt> can be used it must be resolved. This method - * is deprecated in favor of the version that takes a <a - * href="#name">binary name</a> as its first argument, and is more secure. - * - * @param b - * The bytes that make up the class data. The bytes in positions - * <tt>off</tt> through <tt>off+len-1</tt> should have the format - * of a valid class file as defined by - * <cite>The Java™ Virtual Machine Specification</cite>. - * - * @param off - * The start offset in <tt>b</tt> of the class data - * - * @param len - * The length of the class data - * - * @return The <tt>Class</tt> object that was created from the specified - * class data - * - * @throws ClassFormatError - * If the data did not contain a valid class - * - * @throws IndexOutOfBoundsException - * If either <tt>off</tt> or <tt>len</tt> is negative, or if - * <tt>off+len</tt> is greater than <tt>b.length</tt>. - * - * @throws SecurityException - * If an attempt is made to add this class to a package that - * contains classes that were signed by a different set of - * certificates than this class, or if an attempt is made - * to define a class in a package with a fully-qualified name - * that starts with "{@code java.}". - * - * @see #loadClass(String, boolean) - * @see #resolveClass(Class) - * - * @deprecated Replaced by {@link #defineClass(String, byte[], int, int) - * defineClass(String, byte[], int, int)} - */ - @Deprecated - protected final Class<?> defineClass(byte[] b, int off, int len) - throws ClassFormatError - { - return defineClass(null, b, off, len, null); - } - - /** - * Converts an array of bytes into an instance of class <tt>Class</tt>. - * Before the <tt>Class</tt> can be used it must be resolved. - * - * <p> This method assigns a default {@link java.security.ProtectionDomain - * <tt>ProtectionDomain</tt>} to the newly defined class. The - * <tt>ProtectionDomain</tt> is effectively granted the same set of - * permissions returned when {@link - * java.security.Policy#getPermissions(java.security.CodeSource) - * <tt>Policy.getPolicy().getPermissions(new CodeSource(null, null))</tt>} - * is invoked. The default domain is created on the first invocation of - * {@link #defineClass(String, byte[], int, int) <tt>defineClass</tt>}, - * and re-used on subsequent invocations. - * - * <p> To assign a specific <tt>ProtectionDomain</tt> to the class, use - * the {@link #defineClass(String, byte[], int, int, - * java.security.ProtectionDomain) <tt>defineClass</tt>} method that takes a - * <tt>ProtectionDomain</tt> as one of its arguments. </p> - * - * @param name - * The expected <a href="#name">binary name</a> of the class, or - * <tt>null</tt> if not known - * - * @param b - * The bytes that make up the class data. The bytes in positions - * <tt>off</tt> through <tt>off+len-1</tt> should have the format - * of a valid class file as defined by - * <cite>The Java™ Virtual Machine Specification</cite>. - * - * @param off - * The start offset in <tt>b</tt> of the class data - * - * @param len - * The length of the class data - * - * @return The <tt>Class</tt> object that was created from the specified - * class data. - * - * @throws ClassFormatError - * If the data did not contain a valid class - * - * @throws IndexOutOfBoundsException - * If either <tt>off</tt> or <tt>len</tt> is negative, or if - * <tt>off+len</tt> is greater than <tt>b.length</tt>. - * - * @throws SecurityException - * If an attempt is made to add this class to a package that - * contains classes that were signed by a different set of - * certificates than this class (which is unsigned), or if - * <tt>name</tt> begins with "<tt>java.</tt>". - * - * @see #loadClass(String, boolean) - * @see #resolveClass(Class) - * @see java.security.CodeSource - * @see java.security.SecureClassLoader - * - * @since 1.1 - */ - protected final Class<?> defineClass(String name, byte[] b, int off, int len) - throws ClassFormatError - { - return defineClass(name, b, off, len, null); - } - - /* Determine protection domain, and check that: - - not define java.* class, - - signer of this class matches signers for the rest of the classes in - package. - */ - private ProtectionDomain preDefineClass(String name, - ProtectionDomain pd) - { - if (!checkName(name)) - throw new NoClassDefFoundError("IllegalName: " + name); - - if ((name != null) && name.startsWith("java.")) { - throw new SecurityException - ("Prohibited package name: " + - name.substring(0, name.lastIndexOf('.'))); - } - if (pd == null) { - pd = defaultDomain; - } - - if (name != null) checkCerts(name, pd.getCodeSource()); - - return pd; - } - - private String defineClassSourceLocation(ProtectionDomain pd) - { - CodeSource cs = pd.getCodeSource(); - String source = null; - if (cs != null && cs.getLocation() != null) { - source = cs.getLocation().toString(); - } - return source; - } - - private Class defineTransformedClass(String name, byte[] b, int off, int len, - ProtectionDomain pd, - ClassFormatError cfe, String source) - throws ClassFormatError - { - // Class format error - try to transform the bytecode and - // define the class again - // - ClassFileTransformer[] transformers = - ClassFileTransformer.getTransformers(); - Class c = null; - - if (transformers != null) { - for (ClassFileTransformer transformer : transformers) { - try { - // Transform byte code using transformer - byte[] tb = transformer.transform(b, off, len); - c = defineClass1(name, tb, 0, tb.length, - pd, source); - break; - } catch (ClassFormatError cfe2) { - // If ClassFormatError occurs, try next transformer - } - } - } - - // Rethrow original ClassFormatError if unable to transform - // bytecode to well-formed - // - if (c == null) - throw cfe; - - return c; - } - - private void postDefineClass(Class c, ProtectionDomain pd) - { - if (pd.getCodeSource() != null) { - Certificate certs[] = pd.getCodeSource().getCertificates(); - if (certs != null) - setSigners(c, certs); - } - } - - /** - * Converts an array of bytes into an instance of class <tt>Class</tt>, - * with an optional <tt>ProtectionDomain</tt>. If the domain is - * <tt>null</tt>, then a default domain will be assigned to the class as - * specified in the documentation for {@link #defineClass(String, byte[], - * int, int)}. Before the class can be used it must be resolved. - * - * <p> The first class defined in a package determines the exact set of - * certificates that all subsequent classes defined in that package must - * contain. The set of certificates for a class is obtained from the - * {@link java.security.CodeSource <tt>CodeSource</tt>} within the - * <tt>ProtectionDomain</tt> of the class. Any classes added to that - * package must contain the same set of certificates or a - * <tt>SecurityException</tt> will be thrown. Note that if - * <tt>name</tt> is <tt>null</tt>, this check is not performed. - * You should always pass in the <a href="#name">binary name</a> of the - * class you are defining as well as the bytes. This ensures that the - * class you are defining is indeed the class you think it is. - * - * <p> The specified <tt>name</tt> cannot begin with "<tt>java.</tt>", since - * all classes in the "<tt>java.*</tt> packages can only be defined by the - * bootstrap class loader. If <tt>name</tt> is not <tt>null</tt>, it - * must be equal to the <a href="#name">binary name</a> of the class - * specified by the byte array "<tt>b</tt>", otherwise a {@link - * <tt>NoClassDefFoundError</tt>} will be thrown. </p> - * - * @param name - * The expected <a href="#name">binary name</a> of the class, or - * <tt>null</tt> if not known - * - * @param b - * The bytes that make up the class data. The bytes in positions - * <tt>off</tt> through <tt>off+len-1</tt> should have the format - * of a valid class file as defined by - * <cite>The Java™ Virtual Machine Specification</cite>. - * - * @param off - * The start offset in <tt>b</tt> of the class data - * - * @param len - * The length of the class data - * - * @param protectionDomain - * The ProtectionDomain of the class - * - * @return The <tt>Class</tt> object created from the data, - * and optional <tt>ProtectionDomain</tt>. - * - * @throws ClassFormatError - * If the data did not contain a valid class - * - * @throws NoClassDefFoundError - * If <tt>name</tt> is not equal to the <a href="#name">binary - * name</a> of the class specified by <tt>b</tt> - * - * @throws IndexOutOfBoundsException - * If either <tt>off</tt> or <tt>len</tt> is negative, or if - * <tt>off+len</tt> is greater than <tt>b.length</tt>. - * - * @throws SecurityException - * If an attempt is made to add this class to a package that - * contains classes that were signed by a different set of - * certificates than this class, or if <tt>name</tt> begins with - * "<tt>java.</tt>". - */ - protected final Class<?> defineClass(String name, byte[] b, int off, int len, - ProtectionDomain protectionDomain) - throws ClassFormatError - { - check(); - protectionDomain = preDefineClass(name, protectionDomain); - - Class c = null; - String source = defineClassSourceLocation(protectionDomain); - - try { - c = defineClass1(name, b, off, len, protectionDomain, source); - } catch (ClassFormatError cfe) { - c = defineTransformedClass(name, b, off, len, protectionDomain, cfe, - source); - } - - postDefineClass(c, protectionDomain); - return c; - } - - /** - * Converts a {@link java.nio.ByteBuffer <tt>ByteBuffer</tt>} - * into an instance of class <tt>Class</tt>, - * with an optional <tt>ProtectionDomain</tt>. If the domain is - * <tt>null</tt>, then a default domain will be assigned to the class as - * specified in the documentation for {@link #defineClass(String, byte[], - * int, int)}. Before the class can be used it must be resolved. - * - * <p>The rules about the first class defined in a package determining the - * set of certificates for the package, and the restrictions on class names - * are identical to those specified in the documentation for {@link - * #defineClass(String, byte[], int, int, ProtectionDomain)}. - * - * <p> An invocation of this method of the form - * <i>cl</i><tt>.defineClass(</tt><i>name</i><tt>,</tt> - * <i>bBuffer</i><tt>,</tt> <i>pd</i><tt>)</tt> yields exactly the same - * result as the statements - * - * <blockquote><tt> - * ...<br> - * byte[] temp = new byte[</tt><i>bBuffer</i><tt>.{@link - * java.nio.ByteBuffer#remaining remaining}()];<br> - * </tt><i>bBuffer</i><tt>.{@link java.nio.ByteBuffer#get(byte[]) - * get}(temp);<br> - * return {@link #defineClass(String, byte[], int, int, ProtectionDomain) - * </tt><i>cl</i><tt>.defineClass}(</tt><i>name</i><tt>, temp, 0, - * temp.length, </tt><i>pd</i><tt>);<br> - * </tt></blockquote> - * - * @param name - * The expected <a href="#name">binary name</a>. of the class, or - * <tt>null</tt> if not known - * - * @param b - * The bytes that make up the class data. The bytes from positions - * <tt>b.position()</tt> through <tt>b.position() + b.limit() -1 - * </tt> should have the format of a valid class file as defined by - * <cite>The Java™ Virtual Machine Specification</cite>. - * - * @param protectionDomain - * The ProtectionDomain of the class, or <tt>null</tt>. - * - * @return The <tt>Class</tt> object created from the data, - * and optional <tt>ProtectionDomain</tt>. - * - * @throws ClassFormatError - * If the data did not contain a valid class. - * - * @throws NoClassDefFoundError - * If <tt>name</tt> is not equal to the <a href="#name">binary - * name</a> of the class specified by <tt>b</tt> - * - * @throws SecurityException - * If an attempt is made to add this class to a package that - * contains classes that were signed by a different set of - * certificates than this class, or if <tt>name</tt> begins with - * "<tt>java.</tt>". - * - * @see #defineClass(String, byte[], int, int, ProtectionDomain) - * - * @since 1.5 - */ - protected final Class<?> defineClass(String name, java.nio.ByteBuffer b, - ProtectionDomain protectionDomain) - throws ClassFormatError - { - check(); - - int len = b.remaining(); - - // Use byte[] if not a direct ByteBufer: - if (!b.isDirect()) { - if (b.hasArray()) { - return defineClass(name, b.array(), - b.position() + b.arrayOffset(), len, - protectionDomain); - } else { - // no array, or read-only array - byte[] tb = new byte[len]; - b.get(tb); // get bytes out of byte buffer. - return defineClass(name, tb, 0, len, protectionDomain); - } - } - - protectionDomain = preDefineClass(name, protectionDomain); - - Class c = null; - String source = defineClassSourceLocation(protectionDomain); - - try { - c = defineClass2(name, b, b.position(), len, protectionDomain, - source); - } catch (ClassFormatError cfe) { - byte[] tb = new byte[len]; - b.get(tb); // get bytes out of byte buffer. - c = defineTransformedClass(name, tb, 0, len, protectionDomain, cfe, - source); - } - - postDefineClass(c, protectionDomain); - return c; - } - - private native Class defineClass0(String name, byte[] b, int off, int len, - ProtectionDomain pd); - - private native Class defineClass1(String name, byte[] b, int off, int len, - ProtectionDomain pd, String source); - - private native Class defineClass2(String name, java.nio.ByteBuffer b, - int off, int len, ProtectionDomain pd, - String source); - - // true if the name is null or has the potential to be a valid binary name - static boolean checkName(String name) { - if ((name == null) || (name.length() == 0)) - return true; - if ((name.indexOf('/') != -1) - || (!VM.allowArraySyntax() && (name.charAt(0) == '['))) - return false; - return true; - } - - private void checkCerts(String name, CodeSource cs) { - int i = name.lastIndexOf('.'); - String pname = (i == -1) ? "" : name.substring(0, i); - - Certificate[] certs = null; - if (cs != null) { - certs = cs.getCertificates(); - } - Certificate[] pcerts = null; - if (parallelLockMap == null) { - synchronized (this) { - pcerts = package2certs.get(pname); - if (pcerts == null) { - package2certs.put(pname, (certs == null? nocerts:certs)); - } - } - } else { - pcerts = ((ConcurrentHashMap<String, Certificate[]>)package2certs). - putIfAbsent(pname, (certs == null? nocerts:certs)); - } - if (pcerts != null && !compareCerts(pcerts, certs)) { - throw new SecurityException("class \""+ name + - "\"'s signer information does not match signer information of other classes in the same package"); - } - } - - /** - * check to make sure the certs for the new class (certs) are the same as - * the certs for the first class inserted in the package (pcerts) - */ - private boolean compareCerts(Certificate[] pcerts, - Certificate[] certs) - { - // certs can be null, indicating no certs. - if ((certs == null) || (certs.length == 0)) { - return pcerts.length == 0; - } - - // the length must be the same at this point - if (certs.length != pcerts.length) - return false; - - // go through and make sure all the certs in one array - // are in the other and vice-versa. - boolean match; - for (int i = 0; i < certs.length; i++) { - match = false; - for (int j = 0; j < pcerts.length; j++) { - if (certs[i].equals(pcerts[j])) { - match = true; - break; - } - } - if (!match) return false; - } - - // now do the same for pcerts - for (int i = 0; i < pcerts.length; i++) { - match = false; - for (int j = 0; j < certs.length; j++) { - if (pcerts[i].equals(certs[j])) { - match = true; - break; - } - } - if (!match) return false; - } - - return true; - } - - /** - * Links the specified class. This (misleadingly named) method may be - * used by a class loader to link a class. If the class <tt>c</tt> has - * already been linked, then this method simply returns. Otherwise, the - * class is linked as described in the "Execution" chapter of - * <cite>The Java™ Language Specification</cite>. - * </p> - * - * @param c - * The class to link - * - * @throws NullPointerException - * If <tt>c</tt> is <tt>null</tt>. - * - * @see #defineClass(String, byte[], int, int) - */ - protected final void resolveClass(Class<?> c) { - check(); - resolveClass0(c); - } - - private native void resolveClass0(Class c); - - /** - * Finds a class with the specified <a href="#name">binary name</a>, - * loading it if necessary. - * - * <p> This method loads the class through the system class loader (see - * {@link #getSystemClassLoader()}). The <tt>Class</tt> object returned - * might have more than one <tt>ClassLoader</tt> associated with it. - * Subclasses of <tt>ClassLoader</tt> need not usually invoke this method, - * because most class loaders need to override just {@link - * #findClass(String)}. </p> - * - * @param name - * The <a href="#name">binary name</a> of the class - * - * @return The <tt>Class</tt> object for the specified <tt>name</tt> - * - * @throws ClassNotFoundException - * If the class could not be found - * - * @see #ClassLoader(ClassLoader) - * @see #getParent() - */ - protected final Class<?> findSystemClass(String name) - throws ClassNotFoundException - { - check(); - ClassLoader system = getSystemClassLoader(); - if (system == null) { - if (!checkName(name)) - throw new ClassNotFoundException(name); - Class cls = findBootstrapClass(name); - if (cls == null) { - throw new ClassNotFoundException(name); - } - return cls; - } - return system.loadClass(name); - } - - /** - * Returns a class loaded by the bootstrap class loader; - * or return null if not found. - */ - private Class findBootstrapClassOrNull(String name) - { - check(); - if (!checkName(name)) return null; - - return findBootstrapClass(name); - } - - // return null if not found - private native Class findBootstrapClass(String name); - - // Check to make sure the class loader has been initialized. - private void check() { - if (!initialized) { - throw new SecurityException("ClassLoader object not initialized"); - } - } - - /** - * Returns the class with the given <a href="#name">binary name</a> if this - * loader has been recorded by the Java virtual machine as an initiating - * loader of a class with that <a href="#name">binary name</a>. Otherwise - * <tt>null</tt> is returned. </p> - * - * @param name - * The <a href="#name">binary name</a> of the class - * - * @return The <tt>Class</tt> object, or <tt>null</tt> if the class has - * not been loaded - * - * @since 1.1 - */ - protected final Class<?> findLoadedClass(String name) { - check(); - if (!checkName(name)) - return null; - return findLoadedClass0(name); - } - - private native final Class findLoadedClass0(String name); - - /** - * Sets the signers of a class. This should be invoked after defining a - * class. </p> - * - * @param c - * The <tt>Class</tt> object - * - * @param signers - * The signers for the class - * - * @since 1.1 - */ - protected final void setSigners(Class<?> c, Object[] signers) { - check(); - c.setSigners(signers); - } - - - // -- Resource -- - - /** - * Finds the resource with the given name. A resource is some data - * (images, audio, text, etc) that can be accessed by class code in a way - * that is independent of the location of the code. - * - * <p> The name of a resource is a '<tt>/</tt>'-separated path name that - * identifies the resource. - * - * <p> This method will first search the parent class loader for the - * resource; if the parent is <tt>null</tt> the path of the class loader - * built-in to the virtual machine is searched. That failing, this method - * will invoke {@link #findResource(String)} to find the resource. </p> - * - * @param name - * The resource name - * - * @return A <tt>URL</tt> object for reading the resource, or - * <tt>null</tt> if the resource could not be found or the invoker - * doesn't have adequate privileges to get the resource. - * - * @since 1.1 - */ - public URL getResource(String name) { - URL url; - if (parent != null) { - url = parent.getResource(name); - } else { - url = getBootstrapResource(name); - } - if (url == null) { - url = findResource(name); - } - return url; - } - - /** - * Finds all the resources with the given name. A resource is some data - * (images, audio, text, etc) that can be accessed by class code in a way - * that is independent of the location of the code. - * - * <p>The name of a resource is a <tt>/</tt>-separated path name that - * identifies the resource. - * - * <p> The search order is described in the documentation for {@link - * #getResource(String)}. </p> - * - * @param name - * The resource name - * - * @return An enumeration of {@link java.net.URL <tt>URL</tt>} objects for - * the resource. If no resources could be found, the enumeration - * will be empty. Resources that the class loader doesn't have - * access to will not be in the enumeration. - * - * @throws IOException - * If I/O errors occur - * - * @see #findResources(String) - * - * @since 1.2 - */ - public Enumeration<URL> getResources(String name) throws IOException { - Enumeration[] tmp = new Enumeration[2]; - if (parent != null) { - tmp[0] = parent.getResources(name); - } else { - tmp[0] = getBootstrapResources(name); - } - tmp[1] = findResources(name); - - return new CompoundEnumeration<>(tmp); - } - - /** - * Finds the resource with the given name. Class loader implementations - * should override this method to specify where to find resources. </p> - * - * @param name - * The resource name - * - * @return A <tt>URL</tt> object for reading the resource, or - * <tt>null</tt> if the resource could not be found - * - * @since 1.2 - */ - protected URL findResource(String name) { - return null; - } - - /** - * Returns an enumeration of {@link java.net.URL <tt>URL</tt>} objects - * representing all the resources with the given name. Class loader - * implementations should override this method to specify where to load - * resources from. </p> - * - * @param name - * The resource name - * - * @return An enumeration of {@link java.net.URL <tt>URL</tt>} objects for - * the resources - * - * @throws IOException - * If I/O errors occur - * - * @since 1.2 - */ - protected Enumeration<URL> findResources(String name) throws IOException { - return java.util.Collections.emptyEnumeration(); - } - - /** - * Registers the caller as parallel capable.</p> - * The registration succeeds if and only if all of the following - * conditions are met: <br> - * 1. no instance of the caller has been created</p> - * 2. all of the super classes (except class Object) of the caller are - * registered as parallel capable</p> - * Note that once a class loader is registered as parallel capable, there - * is no way to change it back. </p> - * - * @return true if the caller is successfully registered as - * parallel capable and false if otherwise. - * - * @since 1.7 - */ - @CallerSensitive - protected static boolean registerAsParallelCapable() { - Class<? extends ClassLoader> callerClass = - Reflection.getCallerClass().asSubclass(ClassLoader.class); - return ParallelLoaders.register(callerClass); - } - - /** - * Find a resource of the specified name from the search path used to load - * classes. This method locates the resource through the system class - * loader (see {@link #getSystemClassLoader()}). </p> - * - * @param name - * The resource name - * - * @return A {@link java.net.URL <tt>URL</tt>} object for reading the - * resource, or <tt>null</tt> if the resource could not be found - * - * @since 1.1 - */ - public static URL getSystemResource(String name) { - ClassLoader system = getSystemClassLoader(); - if (system == null) { - return getBootstrapResource(name); - } - return system.getResource(name); - } - - /** - * Finds all resources of the specified name from the search path used to - * load classes. The resources thus found are returned as an - * {@link java.util.Enumeration <tt>Enumeration</tt>} of {@link - * java.net.URL <tt>URL</tt>} objects. - * - * <p> The search order is described in the documentation for {@link - * #getSystemResource(String)}. </p> - * - * @param name - * The resource name - * - * @return An enumeration of resource {@link java.net.URL <tt>URL</tt>} - * objects - * - * @throws IOException - * If I/O errors occur - - * @since 1.2 - */ - public static Enumeration<URL> getSystemResources(String name) - throws IOException - { - ClassLoader system = getSystemClassLoader(); - if (system == null) { - return getBootstrapResources(name); - } - return system.getResources(name); - } - - /** - * Find resources from the VM's built-in classloader. - */ - private static native URL getBootstrapResource(String name); - - /** - * Find resources from the VM's built-in classloader. - */ - private static native Enumeration<URL> getBootstrapResources(String name) - throws IOException; - - // Returns the URLClassPath that is used for finding system resources. - static URLClassPath getBootstrapClassPath() { - return sun.misc.Launcher.getBootstrapClassPath(); - } - - - /** - * Returns an input stream for reading the specified resource. - * - * <p> The search order is described in the documentation for {@link - * #getResource(String)}. </p> - * - * @param name - * The resource name - * - * @return An input stream for reading the resource, or <tt>null</tt> - * if the resource could not be found - * - * @since 1.1 - */ - public InputStream getResourceAsStream(String name) { - URL url = getResource(name); - try { - return url != null ? url.openStream() : null; - } catch (IOException e) { - return null; - } - } - - /** - * Open for reading, a resource of the specified name from the search path - * used to load classes. This method locates the resource through the - * system class loader (see {@link #getSystemClassLoader()}). </p> - * - * @param name - * The resource name - * - * @return An input stream for reading the resource, or <tt>null</tt> - * if the resource could not be found - * - * @since 1.1 - */ - public static InputStream getSystemResourceAsStream(String name) { - URL url = getSystemResource(name); - try { - return url != null ? url.openStream() : null; - } catch (IOException e) { - return null; - } - } - - - // -- Hierarchy -- - - /** - * Returns the parent class loader for delegation. Some implementations may - * use <tt>null</tt> to represent the bootstrap class loader. This method - * will return <tt>null</tt> in such implementations if this class loader's - * parent is the bootstrap class loader. - * - * <p> If a security manager is present, and the invoker's class loader is - * not <tt>null</tt> and is not an ancestor of this class loader, then this - * method invokes the security manager's {@link - * SecurityManager#checkPermission(java.security.Permission) - * <tt>checkPermission</tt>} method with a {@link - * RuntimePermission#RuntimePermission(String) - * <tt>RuntimePermission("getClassLoader")</tt>} permission to verify - * access to the parent class loader is permitted. If not, a - * <tt>SecurityException</tt> will be thrown. </p> - * - * @return The parent <tt>ClassLoader</tt> - * - * @throws SecurityException - * If a security manager exists and its <tt>checkPermission</tt> - * method doesn't allow access to this class loader's parent class - * loader. - * - * @since 1.2 - */ - @CallerSensitive - public final ClassLoader getParent() { - if (parent == null) - return null; - SecurityManager sm = System.getSecurityManager(); - if (sm != null) { - checkClassLoaderPermission(parent, Reflection.getCallerClass()); - } - return parent; - } - - /** - * Returns the system class loader for delegation. This is the default - * delegation parent for new <tt>ClassLoader</tt> instances, and is - * typically the class loader used to start the application. - * - * <p> This method is first invoked early in the runtime's startup - * sequence, at which point it creates the system class loader and sets it - * as the context class loader of the invoking <tt>Thread</tt>. - * - * <p> The default system class loader is an implementation-dependent - * instance of this class. - * - * <p> If the system property "<tt>java.system.class.loader</tt>" is defined - * when this method is first invoked then the value of that property is - * taken to be the name of a class that will be returned as the system - * class loader. The class is loaded using the default system class loader - * and must define a public constructor that takes a single parameter of - * type <tt>ClassLoader</tt> which is used as the delegation parent. An - * instance is then created using this constructor with the default system - * class loader as the parameter. The resulting class loader is defined - * to be the system class loader. - * - * <p> If a security manager is present, and the invoker's class loader is - * not <tt>null</tt> and the invoker's class loader is not the same as or - * an ancestor of the system class loader, then this method invokes the - * security manager's {@link - * SecurityManager#checkPermission(java.security.Permission) - * <tt>checkPermission</tt>} method with a {@link - * RuntimePermission#RuntimePermission(String) - * <tt>RuntimePermission("getClassLoader")</tt>} permission to verify - * access to the system class loader. If not, a - * <tt>SecurityException</tt> will be thrown. </p> - * - * @return The system <tt>ClassLoader</tt> for delegation, or - * <tt>null</tt> if none - * - * @throws SecurityException - * If a security manager exists and its <tt>checkPermission</tt> - * method doesn't allow access to the system class loader. - * - * @throws IllegalStateException - * If invoked recursively during the construction of the class - * loader specified by the "<tt>java.system.class.loader</tt>" - * property. - * - * @throws Error - * If the system property "<tt>java.system.class.loader</tt>" - * is defined but the named class could not be loaded, the - * provider class does not define the required constructor, or an - * exception is thrown by that constructor when it is invoked. The - * underlying cause of the error can be retrieved via the - * {@link Throwable#getCause()} method. - * - * @revised 1.4 - */ - @CallerSensitive - public static ClassLoader getSystemClassLoader() { - initSystemClassLoader(); - if (scl == null) { - return null; - } - SecurityManager sm = System.getSecurityManager(); - if (sm != null) { - checkClassLoaderPermission(scl, Reflection.getCallerClass()); - } - return scl; - } - - private static synchronized void initSystemClassLoader() { - if (!sclSet) { - if (scl != null) - throw new IllegalStateException("recursive invocation"); - sun.misc.Launcher l = sun.misc.Launcher.getLauncher(); - if (l != null) { - Throwable oops = null; - scl = l.getClassLoader(); - try { - scl = AccessController.doPrivileged( - new SystemClassLoaderAction(scl)); - } catch (PrivilegedActionException pae) { - oops = pae.getCause(); - if (oops instanceof InvocationTargetException) { - oops = oops.getCause(); - } - } - if (oops != null) { - if (oops instanceof Error) { - throw (Error) oops; - } else { - // wrap the exception - throw new Error(oops); - } - } - } - sclSet = true; - } - } - - // Returns true if the specified class loader can be found in this class - // loader's delegation chain. - boolean isAncestor(ClassLoader cl) { - ClassLoader acl = this; - do { - acl = acl.parent; - if (cl == acl) { - return true; - } - } while (acl != null); - return false; - } - - // Tests if class loader access requires "getClassLoader" permission - // check. A class loader 'from' can access class loader 'to' if - // class loader 'from' is same as class loader 'to' or an ancestor - // of 'to'. The class loader in a system domain can access - // any class loader. - private static boolean needsClassLoaderPermissionCheck(ClassLoader from, - ClassLoader to) - { - if (from == to) - return false; - - if (from == null) - return false; - - return !to.isAncestor(from); - } - - // Returns the class's class loader, or null if none. - static ClassLoader getClassLoader(Class<?> caller) { - // This can be null if the VM is requesting it - if (caller == null) { - return null; - } - // Circumvent security check since this is package-private - return caller.getClassLoader0(); - } - - static void checkClassLoaderPermission(ClassLoader cl, Class<?> caller) { - SecurityManager sm = System.getSecurityManager(); - if (sm != null) { - // caller can be null if the VM is requesting it - ClassLoader ccl = getClassLoader(caller); - if (needsClassLoaderPermissionCheck(ccl, cl)) { - sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION); - } - } - } - - // The class loader for the system - // @GuardedBy("ClassLoader.class") - private static ClassLoader scl; - - // Set to true once the system class loader has been set - // @GuardedBy("ClassLoader.class") - private static boolean sclSet; - - - // -- Package -- - - /** - * Defines a package by name in this <tt>ClassLoader</tt>. This allows - * class loaders to define the packages for their classes. Packages must - * be created before the class is defined, and package names must be - * unique within a class loader and cannot be redefined or changed once - * created. </p> - * - * @param name - * The package name - * - * @param specTitle - * The specification title - * - * @param specVersion - * The specification version - * - * @param specVendor - * The specification vendor - * - * @param implTitle - * The implementation title - * - * @param implVersion - * The implementation version - * - * @param implVendor - * The implementation vendor - * - * @param sealBase - * If not <tt>null</tt>, then this package is sealed with - * respect to the given code source {@link java.net.URL - * <tt>URL</tt>} object. Otherwise, the package is not sealed. - * - * @return The newly defined <tt>Package</tt> object - * - * @throws IllegalArgumentException - * If package name duplicates an existing package either in this - * class loader or one of its ancestors - * - * @since 1.2 - */ - protected Package definePackage(String name, String specTitle, - String specVersion, String specVendor, - String implTitle, String implVersion, - String implVendor, URL sealBase) - throws IllegalArgumentException - { - synchronized (packages) { - Package pkg = getPackage(name); - if (pkg != null) { - throw new IllegalArgumentException(name); - } - pkg = new Package(name, specTitle, specVersion, specVendor, - implTitle, implVersion, implVendor, - sealBase, this); - packages.put(name, pkg); - return pkg; - } - } - - /** - * Returns a <tt>Package</tt> that has been defined by this class loader - * or any of its ancestors. </p> - * - * @param name - * The package name - * - * @return The <tt>Package</tt> corresponding to the given name, or - * <tt>null</tt> if not found - * - * @since 1.2 - */ - protected Package getPackage(String name) { - Package pkg; - synchronized (packages) { - pkg = packages.get(name); - } - if (pkg == null) { - if (parent != null) { - pkg = parent.getPackage(name); - } else { - pkg = Package.getSystemPackage(name); - } - if (pkg != null) { - synchronized (packages) { - Package pkg2 = packages.get(name); - if (pkg2 == null) { - packages.put(name, pkg); - } else { - pkg = pkg2; - } - } - } - } - return pkg; - } - - /** - * Returns all of the <tt>Packages</tt> defined by this class loader and - * its ancestors. </p> - * - * @return The array of <tt>Package</tt> objects defined by this - * <tt>ClassLoader</tt> - * - * @since 1.2 - */ - protected Package[] getPackages() { - Map<String, Package> map; - synchronized (packages) { - map = new HashMap<>(packages); - } - Package[] pkgs; - if (parent != null) { - pkgs = parent.getPackages(); - } else { - pkgs = Package.getSystemPackages(); - } - if (pkgs != null) { - for (int i = 0; i < pkgs.length; i++) { - String pkgName = pkgs[i].getName(); - if (map.get(pkgName) == null) { - map.put(pkgName, pkgs[i]); - } - } - } - return map.values().toArray(new Package[map.size()]); - } - - - // -- Native library access -- - - /** - * Returns the absolute path name of a native library. The VM invokes this - * method to locate the native libraries that belong to classes loaded with - * this class loader. If this method returns <tt>null</tt>, the VM - * searches the library along the path specified as the - * "<tt>java.library.path</tt>" property. </p> - * - * @param libname - * The library name - * - * @return The absolute path of the native library - * - * @see System#loadLibrary(String) - * @see System#mapLibraryName(String) - * - * @since 1.2 - */ - protected String findLibrary(String libname) { - return null; - } - - /** - * The inner class NativeLibrary denotes a loaded native library instance. - * Every classloader contains a vector of loaded native libraries in the - * private field <tt>nativeLibraries</tt>. The native libraries loaded - * into the system are entered into the <tt>systemNativeLibraries</tt> - * vector. - * - * <p> Every native library requires a particular version of JNI. This is - * denoted by the private <tt>jniVersion</tt> field. This field is set by - * the VM when it loads the library, and used by the VM to pass the correct - * version of JNI to the native methods. </p> - * - * @see ClassLoader - * @since 1.2 - */ - static class NativeLibrary { - // opaque handle to native library, used in native code. - long handle; - // the version of JNI environment the native library requires. - private int jniVersion; - // the class from which the library is loaded, also indicates - // the loader this native library belongs. - Class fromClass; - // the canonicalized name of the native library. - String name; - - native void load(String name); - native long find(String name); - native void unload(); - - public NativeLibrary(Class fromClass, String name) { - this.name = name; - this.fromClass = fromClass; - } - - protected void finalize() { - synchronized (loadedLibraryNames) { - if (fromClass.getClassLoader() != null && handle != 0) { - /* remove the native library name */ - int size = loadedLibraryNames.size(); - for (int i = 0; i < size; i++) { - if (name.equals(loadedLibraryNames.elementAt(i))) { - loadedLibraryNames.removeElementAt(i); - break; - } - } - /* unload the library. */ - ClassLoader.nativeLibraryContext.push(this); - try { - unload(); - } finally { - ClassLoader.nativeLibraryContext.pop(); - } - } - } - } - // Invoked in the VM to determine the context class in - // JNI_Load/JNI_Unload - static Class getFromClass() { - return ClassLoader.nativeLibraryContext.peek().fromClass; - } - } - - // All native library names we've loaded. - private static Vector<String> loadedLibraryNames = new Vector<>(); - - // Native libraries belonging to system classes. - private static Vector<NativeLibrary> systemNativeLibraries - = new Vector<>(); - - // Native libraries associated with the class loader. - private Vector<NativeLibrary> nativeLibraries = new Vector<>(); - - // native libraries being loaded/unloaded. - private static Stack<NativeLibrary> nativeLibraryContext = new Stack<>(); - - // The paths searched for libraries - private static String usr_paths[]; - private static String sys_paths[]; - - private static String[] initializePath(String ldpath) { - String ps = File.pathSeparator; - int ldlen = ldpath.length(); - int i, j, n; - // Count the separators in the path - i = ldpath.indexOf(ps); - n = 0; - while (i >= 0) { - n++; - i = ldpath.indexOf(ps, i + 1); - } - - // allocate the array of paths - n :'s = n + 1 path elements - String[] paths = new String[n + 1]; - - // Fill the array with paths from the ldpath - n = i = 0; - j = ldpath.indexOf(ps); - while (j >= 0) { - if (j - i > 0) { - paths[n++] = ldpath.substring(i, j); - } else if (j - i == 0) { - paths[n++] = "."; - } - i = j + 1; - j = ldpath.indexOf(ps, i); - } - paths[n] = ldpath.substring(i, ldlen); - return paths; - } - - private static String java_library_path; - private static String sun_boot_library_path; - - static void initializeLibraryPaths(java.util.Properties props) - { - java_library_path = props.getProperty("java.library.path", ""); - sun_boot_library_path = props.getProperty("sun.boot.library.path", ""); - } - - // Invoked in the java.lang.Runtime class to implement load and loadLibrary. - static void loadLibrary(Class fromClass, String name, - boolean isAbsolute) { - ClassLoader loader = - (fromClass == null) ? null : fromClass.getClassLoader(); - if (sys_paths == null) { - usr_paths = initializePath(java_library_path); - sys_paths = initializePath(sun_boot_library_path); - } - if (isAbsolute) { - if (loadLibrary0(fromClass, new File(name))) { - return; - } - throw new UnsatisfiedLinkError("Can't load library: " + name); - } - if (loader != null) { - String libfilename = loader.findLibrary(name); - if (libfilename != null) { - File libfile = new File(libfilename); - if (!libfile.isAbsolute()) { - throw new UnsatisfiedLinkError( - "ClassLoader.findLibrary failed to return an absolute path: " + libfilename); - } - if (loadLibrary0(fromClass, libfile)) { - return; - } - throw new UnsatisfiedLinkError("Can't load " + libfilename); - } - } - for (int i = 0 ; i < sys_paths.length ; i++) { - File libfile = new File(sys_paths[i], System.mapLibraryName(name)); - if (loadLibrary0(fromClass, libfile)) { - return; - } - } - if (loader != null) { - for (int i = 0 ; i < usr_paths.length ; i++) { - File libfile = new File(usr_paths[i], - System.mapLibraryName(name)); - if (loadLibrary0(fromClass, libfile)) { - return; - } - } - } - // Oops, it failed - throw new UnsatisfiedLinkError("no " + name + " in java.library.path"); - } - - private static boolean loadLibrary0(Class fromClass, final File file) { - if (loadLibrary1(fromClass, file)) { - return true; - } - final File libfile = ClassLoaderHelper.mapAlternativeName(file); - if (libfile != null && loadLibrary1(fromClass, libfile)) { - return true; - } - return false; - } - - private static boolean loadLibrary1(Class fromClass, final File file) { - boolean exists = AccessController.doPrivileged( - new PrivilegedAction<Object>() { - public Object run() { - return file.exists() ? Boolean.TRUE : null; - }}) - != null; - if (!exists) { - return false; - } - String name; - try { - name = file.getCanonicalPath(); - } catch (IOException e) { - return false; - } - ClassLoader loader = - (fromClass == null) ? null : fromClass.getClassLoader(); - Vector<NativeLibrary> libs = - loader != null ? loader.nativeLibraries : systemNativeLibraries; - synchronized (libs) { - int size = libs.size(); - for (int i = 0; i < size; i++) { - NativeLibrary lib = libs.elementAt(i); - if (name.equals(lib.name)) { - return true; - } - } - - synchronized (loadedLibraryNames) { - if (loadedLibraryNames.contains(name)) { - throw new UnsatisfiedLinkError - ("Native Library " + - name + - " already loaded in another classloader"); - } - /* If the library is being loaded (must be by the same thread, - * because Runtime.load and Runtime.loadLibrary are - * synchronous). The reason is can occur is that the JNI_OnLoad - * function can cause another loadLibrary invocation. - * - * Thus we can use a static stack to hold the list of libraries - * we are loading. - * - * If there is a pending load operation for the library, we - * immediately return success; otherwise, we raise - * UnsatisfiedLinkError. - */ - int n = nativeLibraryContext.size(); - for (int i = 0; i < n; i++) { - NativeLibrary lib = nativeLibraryContext.elementAt(i); - if (name.equals(lib.name)) { - if (loader == lib.fromClass.getClassLoader()) { - return true; - } else { - throw new UnsatisfiedLinkError - ("Native Library " + - name + - " is being loaded in another classloader"); - } - } - } - NativeLibrary lib = new NativeLibrary(fromClass, name); - nativeLibraryContext.push(lib); - try { - lib.load(name); - } finally { - nativeLibraryContext.pop(); - } - if (lib.handle != 0) { - loadedLibraryNames.addElement(name); - libs.addElement(lib); - return true; - } - return false; - } - } - } - - // Invoked in the VM class linking code. - static long findNative(ClassLoader loader, String name) { - Vector<NativeLibrary> libs = - loader != null ? loader.nativeLibraries : systemNativeLibraries; - synchronized (libs) { - int size = libs.size(); - for (int i = 0; i < size; i++) { - NativeLibrary lib = libs.elementAt(i); - long entry = lib.find(name); - if (entry != 0) - return entry; - } - } - return 0; - } - - - // -- Assertion management -- - - final Object assertionLock; - - // The default toggle for assertion checking. - // @GuardedBy("assertionLock") - private boolean defaultAssertionStatus = false; - - // Maps String packageName to Boolean package default assertion status Note - // that the default package is placed under a null map key. If this field - // is null then we are delegating assertion status queries to the VM, i.e., - // none of this ClassLoader's assertion status modification methods have - // been invoked. - // @GuardedBy("assertionLock") - private Map<String, Boolean> packageAssertionStatus = null; - - // Maps String fullyQualifiedClassName to Boolean assertionStatus If this - // field is null then we are delegating assertion status queries to the VM, - // i.e., none of this ClassLoader's assertion status modification methods - // have been invoked. - // @GuardedBy("assertionLock") - Map<String, Boolean> classAssertionStatus = null; - - /** - * Sets the default assertion status for this class loader. This setting - * determines whether classes loaded by this class loader and initialized - * in the future will have assertions enabled or disabled by default. - * This setting may be overridden on a per-package or per-class basis by - * invoking {@link #setPackageAssertionStatus(String, boolean)} or {@link - * #setClassAssertionStatus(String, boolean)}. </p> - * - * @param enabled - * <tt>true</tt> if classes loaded by this class loader will - * henceforth have assertions enabled by default, <tt>false</tt> - * if they will have assertions disabled by default. - * - * @since 1.4 - */ - public void setDefaultAssertionStatus(boolean enabled) { - synchronized (assertionLock) { - if (classAssertionStatus == null) - initializeJavaAssertionMaps(); - - defaultAssertionStatus = enabled; - } - } - - /** - * Sets the package default assertion status for the named package. The - * package default assertion status determines the assertion status for - * classes initialized in the future that belong to the named package or - * any of its "subpackages". - * - * <p> A subpackage of a package named p is any package whose name begins - * with "<tt>p.</tt>". For example, <tt>javax.swing.text</tt> is a - * subpackage of <tt>javax.swing</tt>, and both <tt>java.util</tt> and - * <tt>java.lang.reflect</tt> are subpackages of <tt>java</tt>. - * - * <p> In the event that multiple package defaults apply to a given class, - * the package default pertaining to the most specific package takes - * precedence over the others. For example, if <tt>javax.lang</tt> and - * <tt>javax.lang.reflect</tt> both have package defaults associated with - * them, the latter package default applies to classes in - * <tt>javax.lang.reflect</tt>. - * - * <p> Package defaults take precedence over the class loader's default - * assertion status, and may be overridden on a per-class basis by invoking - * {@link #setClassAssertionStatus(String, boolean)}. </p> - * - * @param packageName - * The name of the package whose package default assertion status - * is to be set. A <tt>null</tt> value indicates the unnamed - * package that is "current" - * (see section 7.4.2 of - * <cite>The Java™ Language Specification</cite>.) - * - * @param enabled - * <tt>true</tt> if classes loaded by this classloader and - * belonging to the named package or any of its subpackages will - * have assertions enabled by default, <tt>false</tt> if they will - * have assertions disabled by default. - * - * @since 1.4 - */ - public void setPackageAssertionStatus(String packageName, - boolean enabled) { - synchronized (assertionLock) { - if (packageAssertionStatus == null) - initializeJavaAssertionMaps(); - - packageAssertionStatus.put(packageName, enabled); - } - } - - /** - * Sets the desired assertion status for the named top-level class in this - * class loader and any nested classes contained therein. This setting - * takes precedence over the class loader's default assertion status, and - * over any applicable per-package default. This method has no effect if - * the named class has already been initialized. (Once a class is - * initialized, its assertion status cannot change.) - * - * <p> If the named class is not a top-level class, this invocation will - * have no effect on the actual assertion status of any class. </p> - * - * @param className - * The fully qualified class name of the top-level class whose - * assertion status is to be set. - * - * @param enabled - * <tt>true</tt> if the named class is to have assertions - * enabled when (and if) it is initialized, <tt>false</tt> if the - * class is to have assertions disabled. - * - * @since 1.4 - */ - public void setClassAssertionStatus(String className, boolean enabled) { - synchronized (assertionLock) { - if (classAssertionStatus == null) - initializeJavaAssertionMaps(); - - classAssertionStatus.put(className, enabled); - } - } - - /** - * Sets the default assertion status for this class loader to - * <tt>false</tt> and discards any package defaults or class assertion - * status settings associated with the class loader. This method is - * provided so that class loaders can be made to ignore any command line or - * persistent assertion status settings and "start with a clean slate." - * </p> - * - * @since 1.4 - */ - public void clearAssertionStatus() { - /* - * Whether or not "Java assertion maps" are initialized, set - * them to empty maps, effectively ignoring any present settings. - */ - synchronized (assertionLock) { - classAssertionStatus = new HashMap<>(); - packageAssertionStatus = new HashMap<>(); - defaultAssertionStatus = false; - } - } - - /** - * Returns the assertion status that would be assigned to the specified - * class if it were to be initialized at the time this method is invoked. - * If the named class has had its assertion status set, the most recent - * setting will be returned; otherwise, if any package default assertion - * status pertains to this class, the most recent setting for the most - * specific pertinent package default assertion status is returned; - * otherwise, this class loader's default assertion status is returned. - * </p> - * - * @param className - * The fully qualified class name of the class whose desired - * assertion status is being queried. - * - * @return The desired assertion status of the specified class. - * - * @see #setClassAssertionStatus(String, boolean) - * @see #setPackageAssertionStatus(String, boolean) - * @see #setDefaultAssertionStatus(boolean) - * - * @since 1.4 - */ - boolean desiredAssertionStatus(String className) { - synchronized (assertionLock) { - // assert classAssertionStatus != null; - // assert packageAssertionStatus != null; - - // Check for a class entry - Boolean result = classAssertionStatus.get(className); - if (result != null) - return result.booleanValue(); - - // Check for most specific package entry - int dotIndex = className.lastIndexOf("."); - if (dotIndex < 0) { // default package - result = packageAssertionStatus.get(null); - if (result != null) - return result.booleanValue(); - } - while(dotIndex > 0) { - className = className.substring(0, dotIndex); - result = packageAssertionStatus.get(className); - if (result != null) - return result.booleanValue(); - dotIndex = className.lastIndexOf(".", dotIndex-1); - } - - // Return the classloader default - return defaultAssertionStatus; - } - } - - // Set up the assertions with information provided by the VM. - // Note: Should only be called inside a synchronized block - private void initializeJavaAssertionMaps() { - // assert Thread.holdsLock(assertionLock); - - classAssertionStatus = new HashMap<>(); - packageAssertionStatus = new HashMap<>(); - AssertionStatusDirectives directives = retrieveDirectives(); - - for(int i = 0; i < directives.classes.length; i++) - classAssertionStatus.put(directives.classes[i], - directives.classEnabled[i]); - - for(int i = 0; i < directives.packages.length; i++) - packageAssertionStatus.put(directives.packages[i], - directives.packageEnabled[i]); - - defaultAssertionStatus = directives.deflt; - } - - // Retrieves the assertion directives from the VM. - private static native AssertionStatusDirectives retrieveDirectives(); - - // [IKVM] equivalent of HotSpot's java_lang_ClassLoader::is_trusted_loader() - static boolean isTrustedLoader(ClassLoader loader) { - ClassLoader cl = scl; - while (cl != null) { - if (cl == loader) return true; - cl = cl.parent; - } - return false; - } -} - - -class SystemClassLoaderAction - implements PrivilegedExceptionAction<ClassLoader> { - private ClassLoader parent; - - SystemClassLoaderAction(ClassLoader parent) { - this.parent = parent; - } - - public ClassLoader run() throws Exception { - String cls = System.getProperty("java.system.class.loader"); - if (cls == null) { - return parent; - } - - Constructor ctor = Class.forName(cls, true, parent) - .getDeclaredConstructor(new Class[] { ClassLoader.class }); - ClassLoader sys = (ClassLoader) ctor.newInstance( - new Object[] { parent }); - Thread.currentThread().setContextClassLoader(sys); - return sys; - } -} |