2262 lines
84 KiB
Java
2262 lines
84 KiB
Java
/*
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* Copyright (c) 1994, 2011, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package java.lang;
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import java.io.InputStream;
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import java.io.IOException;
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import java.io.File;
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import java.lang.reflect.Constructor;
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import java.lang.reflect.InvocationTargetException;
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import java.net.MalformedURLException;
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import java.net.URL;
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import java.security.AccessController;
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import java.security.AccessControlContext;
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import java.security.CodeSource;
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import java.security.Policy;
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import java.security.PrivilegedAction;
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import java.security.PrivilegedActionException;
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import java.security.PrivilegedExceptionAction;
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import java.security.ProtectionDomain;
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import java.security.cert.Certificate;
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import java.util.Collections;
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import java.util.Enumeration;
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import java.util.HashMap;
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import java.util.HashSet;
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import java.util.Set;
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import java.util.Stack;
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import java.util.Map;
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import java.util.Vector;
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import java.util.Hashtable;
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import java.util.WeakHashMap;
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import java.util.concurrent.ConcurrentHashMap;
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import sun.misc.ClassFileTransformer;
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import sun.misc.CompoundEnumeration;
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import sun.misc.Resource;
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import sun.misc.URLClassPath;
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import sun.misc.VM;
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import sun.reflect.CallerSensitive;
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import sun.reflect.Reflection;
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import sun.security.util.SecurityConstants;
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/**
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* A class loader is an object that is responsible for loading classes. The
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* class <tt>ClassLoader</tt> is an abstract class. Given the <a
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* href="#name">binary name</a> of a class, a class loader should attempt to
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* locate or generate data that constitutes a definition for the class. A
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* typical strategy is to transform the name into a file name and then read a
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* "class file" of that name from a file system.
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*
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* <p> Every {@link Class <tt>Class</tt>} object contains a {@link
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* Class#getClassLoader() reference} to the <tt>ClassLoader</tt> that defined
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* it.
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*
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* <p> <tt>Class</tt> objects for array classes are not created by class
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* loaders, but are created automatically as required by the Java runtime.
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* The class loader for an array class, as returned by {@link
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* Class#getClassLoader()} is the same as the class loader for its element
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* type; if the element type is a primitive type, then the array class has no
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* class loader.
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*
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* <p> Applications implement subclasses of <tt>ClassLoader</tt> in order to
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* extend the manner in which the Java virtual machine dynamically loads
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* classes.
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*
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* <p> Class loaders may typically be used by security managers to indicate
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* security domains.
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*
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* <p> The <tt>ClassLoader</tt> class uses a delegation model to search for
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* classes and resources. Each instance of <tt>ClassLoader</tt> has an
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* associated parent class loader. When requested to find a class or
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* resource, a <tt>ClassLoader</tt> instance will delegate the search for the
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* class or resource to its parent class loader before attempting to find the
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* class or resource itself. The virtual machine's built-in class loader,
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* called the "bootstrap class loader", does not itself have a parent but may
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* serve as the parent of a <tt>ClassLoader</tt> instance.
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*
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* <p> Class loaders that support concurrent loading of classes are known as
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* <em>parallel capable</em> class loaders and are required to register
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* themselves at their class initialization time by invoking the
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* {@link
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* #registerAsParallelCapable <tt>ClassLoader.registerAsParallelCapable</tt>}
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* method. Note that the <tt>ClassLoader</tt> class is registered as parallel
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* capable by default. However, its subclasses still need to register themselves
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* if they are parallel capable. <br>
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* In environments in which the delegation model is not strictly
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* hierarchical, class loaders need to be parallel capable, otherwise class
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* loading can lead to deadlocks because the loader lock is held for the
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* duration of the class loading process (see {@link #loadClass
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* <tt>loadClass</tt>} methods).
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*
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* <p> Normally, the Java virtual machine loads classes from the local file
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* system in a platform-dependent manner. For example, on UNIX systems, the
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* virtual machine loads classes from the directory defined by the
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* <tt>CLASSPATH</tt> environment variable.
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*
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* <p> However, some classes may not originate from a file; they may originate
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* from other sources, such as the network, or they could be constructed by an
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* application. The method {@link #defineClass(String, byte[], int, int)
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* <tt>defineClass</tt>} converts an array of bytes into an instance of class
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* <tt>Class</tt>. Instances of this newly defined class can be created using
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* {@link Class#newInstance <tt>Class.newInstance</tt>}.
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*
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* <p> The methods and constructors of objects created by a class loader may
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* reference other classes. To determine the class(es) referred to, the Java
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* virtual machine invokes the {@link #loadClass <tt>loadClass</tt>} method of
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* the class loader that originally created the class.
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*
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* <p> For example, an application could create a network class loader to
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* download class files from a server. Sample code might look like:
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*
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* <blockquote><pre>
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* ClassLoader loader = new NetworkClassLoader(host, port);
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* Object main = loader.loadClass("Main", true).newInstance();
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* . . .
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* </pre></blockquote>
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*
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* <p> The network class loader subclass must define the methods {@link
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* #findClass <tt>findClass</tt>} and <tt>loadClassData</tt> to load a class
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* from the network. Once it has downloaded the bytes that make up the class,
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* it should use the method {@link #defineClass <tt>defineClass</tt>} to
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* create a class instance. A sample implementation is:
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*
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* <blockquote><pre>
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* class NetworkClassLoader extends ClassLoader {
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* String host;
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* int port;
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*
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* public Class findClass(String name) {
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* byte[] b = loadClassData(name);
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* return defineClass(name, b, 0, b.length);
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* }
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*
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* private byte[] loadClassData(String name) {
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* // load the class data from the connection
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* . . .
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* }
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* }
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* </pre></blockquote>
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*
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* <h4> <a name="name">Binary names</a> </h4>
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*
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* <p> Any class name provided as a {@link String} parameter to methods in
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* <tt>ClassLoader</tt> must be a binary name as defined by
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* <cite>The Java™ Language Specification</cite>.
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*
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* <p> Examples of valid class names include:
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* <blockquote><pre>
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* "java.lang.String"
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* "javax.swing.JSpinner$DefaultEditor"
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* "java.security.KeyStore$Builder$FileBuilder$1"
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* "java.net.URLClassLoader$3$1"
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* </pre></blockquote>
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*
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* @see #resolveClass(Class)
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* @since 1.0
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*/
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public abstract class ClassLoader {
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// If initialization succeed this is set to true and security checks will
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// succeed. Otherwise the object is not initialized and the object is
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// useless.
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private final boolean initialized;
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// The parent class loader for delegation
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// Note: VM hardcoded the offset of this field, thus all new fields
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// must be added *after* it.
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private final ClassLoader parent;
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/**
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* Encapsulates the set of parallel capable loader types.
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*/
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private static class ParallelLoaders {
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private ParallelLoaders() {}
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// the set of parallel capable loader types
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private static final Set<Class<? extends ClassLoader>> loaderTypes =
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Collections.newSetFromMap(
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new WeakHashMap<Class<? extends ClassLoader>, Boolean>());
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static {
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synchronized (loaderTypes) { loaderTypes.add(ClassLoader.class); }
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}
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/**
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* Registers the given class loader type as parallel capabale.
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* Returns {@code true} is successfully registered; {@code false} if
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* loader's super class is not registered.
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*/
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static boolean register(Class<? extends ClassLoader> c) {
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synchronized (loaderTypes) {
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if (loaderTypes.contains(c.getSuperclass())) {
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// register the class loader as parallel capable
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// if and only if all of its super classes are.
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// Note: given current classloading sequence, if
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// the immediate super class is parallel capable,
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// all the super classes higher up must be too.
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loaderTypes.add(c);
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return true;
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} else {
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return false;
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}
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}
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}
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/**
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* Returns {@code true} if the given class loader type is
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* registered as parallel capable.
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*/
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static boolean isRegistered(Class<? extends ClassLoader> c) {
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synchronized (loaderTypes) {
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return loaderTypes.contains(c);
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}
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}
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}
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// Maps class name to the corresponding lock object when the current
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// class loader is parallel capable.
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// Note: VM also uses this field to decide if the current class loader
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// is parallel capable and the appropriate lock object for class loading.
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private final ConcurrentHashMap<String, Object> parallelLockMap;
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// Hashtable that maps packages to certs
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private final Map <String, Certificate[]> package2certs;
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// Shared among all packages with unsigned classes
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private static final Certificate[] nocerts = new Certificate[0];
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// The classes loaded by this class loader. The only purpose of this table
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// is to keep the classes from being GC'ed until the loader is GC'ed.
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private final Vector<Class<?>> classes = new Vector<>();
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// The "default" domain. Set as the default ProtectionDomain on newly
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// created classes.
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private final ProtectionDomain defaultDomain =
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new ProtectionDomain(new CodeSource(null, (Certificate[]) null),
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null, this, null);
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// The initiating protection domains for all classes loaded by this loader
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private final Set<ProtectionDomain> domains;
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// Invoked by the VM to record every loaded class with this loader.
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void addClass(Class c) {
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classes.addElement(c);
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}
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// The packages defined in this class loader. Each package name is mapped
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// to its corresponding Package object.
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// @GuardedBy("itself")
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private final HashMap<String, Package> packages = new HashMap<>();
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@ikvm.lang.Internal
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public static final ClassLoader DUMMY = new ClassLoader(false) { };
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ClassLoader(boolean ignored)
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{
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// [IKVM] This constructor is IKVM specific and only used to construct DUMMY.
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// Note that this body is replaced in map.xml with an empty body as
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// we don't want to execute any of the instance field initializers.
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this((Void)null, (ClassLoader)null);
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}
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private static Void checkCreateClassLoader() {
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SecurityManager security = System.getSecurityManager();
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if (security != null) {
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security.checkCreateClassLoader();
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}
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return null;
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}
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// [IKVM] this normally private constructor is also used by ikvm.runtime.AssemblyClassLoader
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// to construct an assembly class loader without doing a security check
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@ikvm.lang.Internal
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protected ClassLoader(Void unused, ClassLoader parent) {
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if (parent != null) {
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parent.check();
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}
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this.parent = parent;
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if (ParallelLoaders.isRegistered(this.getClass())) {
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parallelLockMap = new ConcurrentHashMap<>();
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package2certs = new ConcurrentHashMap<>();
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domains =
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Collections.synchronizedSet(new HashSet<ProtectionDomain>());
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assertionLock = new Object();
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} else {
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// no finer-grained lock; lock on the classloader instance
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parallelLockMap = null;
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package2certs = new Hashtable<>();
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domains = new HashSet<>();
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assertionLock = this;
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}
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initialized = true;
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}
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/**
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* Creates a new class loader using the specified parent class loader for
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* delegation.
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*
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* <p> If there is a security manager, its {@link
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* SecurityManager#checkCreateClassLoader()
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* <tt>checkCreateClassLoader</tt>} method is invoked. This may result in
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* a security exception. </p>
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*
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* @param parent
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* The parent class loader
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*
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* @throws SecurityException
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* If a security manager exists and its
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* <tt>checkCreateClassLoader</tt> method doesn't allow creation
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* of a new class loader.
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*
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* @since 1.2
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*/
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protected ClassLoader(ClassLoader parent) {
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this(checkCreateClassLoader(), parent);
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}
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/**
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* Creates a new class loader using the <tt>ClassLoader</tt> returned by
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* the method {@link #getSystemClassLoader()
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* <tt>getSystemClassLoader()</tt>} as the parent class loader.
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*
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* <p> If there is a security manager, its {@link
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* SecurityManager#checkCreateClassLoader()
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* <tt>checkCreateClassLoader</tt>} method is invoked. This may result in
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* a security exception. </p>
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*
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* @throws SecurityException
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* If a security manager exists and its
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* <tt>checkCreateClassLoader</tt> method doesn't allow creation
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* of a new class loader.
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*/
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protected ClassLoader() {
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this(checkCreateClassLoader(), getSystemClassLoader());
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}
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// -- Class --
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/**
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* Loads the class with the specified <a href="#name">binary name</a>.
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* This method searches for classes in the same manner as the {@link
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* #loadClass(String, boolean)} method. It is invoked by the Java virtual
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* machine to resolve class references. Invoking this method is equivalent
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* to invoking {@link #loadClass(String, boolean) <tt>loadClass(name,
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* false)</tt>}. </p>
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*
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* @param name
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* The <a href="#name">binary name</a> of the class
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*
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* @return The resulting <tt>Class</tt> object
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*
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* @throws ClassNotFoundException
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* If the class was not found
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*/
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public Class<?> loadClass(String name) throws ClassNotFoundException {
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return loadClass(name, false);
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}
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/**
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* Loads the class with the specified <a href="#name">binary name</a>. The
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* default implementation of this method searches for classes in the
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* following order:
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*
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* <p><ol>
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*
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* <li><p> Invoke {@link #findLoadedClass(String)} to check if the class
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* has already been loaded. </p></li>
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*
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* <li><p> Invoke the {@link #loadClass(String) <tt>loadClass</tt>} method
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* on the parent class loader. If the parent is <tt>null</tt> the class
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* loader built-in to the virtual machine is used, instead. </p></li>
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*
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* <li><p> Invoke the {@link #findClass(String)} method to find the
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* class. </p></li>
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*
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* </ol>
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*
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* <p> If the class was found using the above steps, and the
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* <tt>resolve</tt> flag is true, this method will then invoke the {@link
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* #resolveClass(Class)} method on the resulting <tt>Class</tt> object.
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*
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* <p> Subclasses of <tt>ClassLoader</tt> are encouraged to override {@link
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* #findClass(String)}, rather than this method. </p>
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*
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* <p> Unless overridden, this method synchronizes on the result of
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* {@link #getClassLoadingLock <tt>getClassLoadingLock</tt>} method
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* during the entire class loading process.
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*
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* @param name
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* The <a href="#name">binary name</a> of the class
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*
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* @param resolve
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* If <tt>true</tt> then resolve the class
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*
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* @return The resulting <tt>Class</tt> object
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*
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* @throws ClassNotFoundException
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* If the class could not be found
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*/
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protected Class<?> loadClass(String name, boolean resolve)
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throws ClassNotFoundException
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{
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synchronized (getClassLoadingLock(name)) {
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// First, check if the class has already been loaded
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Class c = findLoadedClass(name);
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if (c == null) {
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try {
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if (parent != null) {
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c = parent.loadClass(name, false);
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} else {
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c = findBootstrapClassOrNull(name);
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}
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} catch (ClassNotFoundException e) {
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// ClassNotFoundException thrown if class not found
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// from the non-null parent class loader
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}
|
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if (c == null) {
|
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// If still not found, then invoke findClass in order
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// to find the class.
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c = findClass(name);
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}
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}
|
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if (resolve) {
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resolveClass(c);
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}
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return c;
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}
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}
|
|
|
|
/**
|
|
* Returns the lock object for class loading operations.
|
|
* For backward compatibility, the default implementation of this method
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|
* behaves as follows. If this ClassLoader object is registered as
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* parallel capable, the method returns a dedicated object associated
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* with the specified class name. Otherwise, the method returns this
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* ClassLoader object. </p>
|
|
*
|
|
* @param className
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|
* The name of the to-be-loaded class
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|
*
|
|
* @return the lock for class loading operations
|
|
*
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|
* @throws NullPointerException
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|
* If registered as parallel capable and <tt>className</tt> is null
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*
|
|
* @see #loadClass(String, boolean)
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*
|
|
* @since 1.7
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|
*/
|
|
protected Object getClassLoadingLock(String className) {
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Object lock = this;
|
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if (parallelLockMap != null) {
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Object newLock = new Object();
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lock = parallelLockMap.putIfAbsent(className, newLock);
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if (lock == null) {
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lock = newLock;
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}
|
|
}
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|
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;
|
|
}
|
|
}
|