jaroslav@601: /*
jaroslav@601: * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
jaroslav@601: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jaroslav@601: *
jaroslav@601: * This code is free software; you can redistribute it and/or modify it
jaroslav@601: * under the terms of the GNU General Public License version 2 only, as
jaroslav@601: * published by the Free Software Foundation. Oracle designates this
jaroslav@601: * particular file as subject to the "Classpath" exception as provided
jaroslav@601: * by Oracle in the LICENSE file that accompanied this code.
jaroslav@601: *
jaroslav@601: * This code is distributed in the hope that it will be useful, but WITHOUT
jaroslav@601: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jaroslav@601: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
jaroslav@601: * version 2 for more details (a copy is included in the LICENSE file that
jaroslav@601: * accompanied this code).
jaroslav@601: *
jaroslav@601: * You should have received a copy of the GNU General Public License version
jaroslav@601: * 2 along with this work; if not, write to the Free Software Foundation,
jaroslav@601: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jaroslav@601: *
jaroslav@601: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jaroslav@601: * or visit www.oracle.com if you need additional information or have any
jaroslav@601: * questions.
jaroslav@601: */
jaroslav@601:
jaroslav@1378: package org.apidesign.bck2brwsr.emul.reflect;
jaroslav@601:
jaroslav@1378: import java.io.ByteArrayOutputStream;
jaroslav@1378: import java.io.DataOutputStream;
jaroslav@1378: import java.io.IOException;
jaroslav@1378: import java.io.OutputStream;
jaroslav@1378: import java.lang.ref.Reference;
jaroslav@1378: import java.lang.ref.WeakReference;
jaroslav@1378: import java.lang.reflect.Array;
jaroslav@1378: import java.lang.reflect.Constructor;
jaroslav@1378: import java.lang.reflect.InvocationHandler;
jaroslav@1378: import java.lang.reflect.InvocationTargetException;
jaroslav@1378: import java.lang.reflect.Method;
jaroslav@1378: import java.lang.reflect.Modifier;
jaroslav@1378: import java.util.ArrayList;
jaroslav@1378: import java.util.Arrays;
jaroslav@1378: import java.util.Collections;
jaroslav@1378: import java.util.HashMap;
jaroslav@1378: import java.util.HashSet;
jaroslav@1378: import java.util.LinkedList;
jaroslav@1378: import java.util.Map;
jaroslav@1378: import java.util.Set;
jaroslav@1378: import java.util.List;
jaroslav@1378: import java.util.ListIterator;
jaroslav@1378: import java.util.WeakHashMap;
jaroslav@1378: import org.apidesign.bck2brwsr.core.JavaScriptBody;
jaroslav@1378: import org.apidesign.bck2brwsr.emul.reflect.MethodImpl;
jaroslav@601:
jaroslav@601: /**
jaroslav@601: * {@code Proxy} provides static methods for creating dynamic proxy
jaroslav@601: * classes and instances, and it is also the superclass of all
jaroslav@601: * dynamic proxy classes created by those methods.
jaroslav@601: *
jaroslav@601: * To create a proxy for some interface {@code Foo}:
jaroslav@601: *
jaroslav@601: * InvocationHandler handler = new MyInvocationHandler(...);
jaroslav@601: * Class proxyClass = Proxy.getProxyClass(
jaroslav@601: * Foo.class.getClassLoader(), new Class[] { Foo.class });
jaroslav@601: * Foo f = (Foo) proxyClass.
jaroslav@601: * getConstructor(new Class[] { InvocationHandler.class }).
jaroslav@601: * newInstance(new Object[] { handler });
jaroslav@601: *
jaroslav@601: * or more simply:
jaroslav@601: *
jaroslav@601: * Foo f = (Foo) Proxy.newProxyInstance(Foo.class.getClassLoader(),
jaroslav@601: * new Class[] { Foo.class },
jaroslav@601: * handler);
jaroslav@601: *
jaroslav@601: *
jaroslav@601: * A dynamic proxy class (simply referred to as a proxy
jaroslav@601: * class below) is a class that implements a list of interfaces
jaroslav@601: * specified at runtime when the class is created, with behavior as
jaroslav@601: * described below.
jaroslav@601: *
jaroslav@601: * A proxy interface is such an interface that is implemented
jaroslav@601: * by a proxy class.
jaroslav@601: *
jaroslav@601: * A proxy instance is an instance of a proxy class.
jaroslav@601: *
jaroslav@601: * Each proxy instance has an associated invocation handler
jaroslav@601: * object, which implements the interface {@link InvocationHandler}.
jaroslav@601: * A method invocation on a proxy instance through one of its proxy
jaroslav@601: * interfaces will be dispatched to the {@link InvocationHandler#invoke
jaroslav@601: * invoke} method of the instance's invocation handler, passing the proxy
jaroslav@601: * instance, a {@code java.lang.reflect.Method} object identifying
jaroslav@601: * the method that was invoked, and an array of type {@code Object}
jaroslav@601: * containing the arguments. The invocation handler processes the
jaroslav@601: * encoded method invocation as appropriate and the result that it
jaroslav@601: * returns will be returned as the result of the method invocation on
jaroslav@601: * the proxy instance.
jaroslav@601: *
jaroslav@601: *
A proxy class has the following properties:
jaroslav@601: *
jaroslav@601: *
jaroslav@601: * - Proxy classes are public, final, and not abstract.
jaroslav@601: *
jaroslav@601: *
- The unqualified name of a proxy class is unspecified. The space
jaroslav@601: * of class names that begin with the string {@code "$Proxy"}
jaroslav@601: * should be, however, reserved for proxy classes.
jaroslav@601: *
jaroslav@601: *
- A proxy class extends {@code java.lang.reflect.Proxy}.
jaroslav@601: *
jaroslav@601: *
- A proxy class implements exactly the interfaces specified at its
jaroslav@601: * creation, in the same order.
jaroslav@601: *
jaroslav@601: *
- If a proxy class implements a non-public interface, then it will
jaroslav@601: * be defined in the same package as that interface. Otherwise, the
jaroslav@601: * package of a proxy class is also unspecified. Note that package
jaroslav@601: * sealing will not prevent a proxy class from being successfully defined
jaroslav@601: * in a particular package at runtime, and neither will classes already
jaroslav@601: * defined by the same class loader and the same package with particular
jaroslav@601: * signers.
jaroslav@601: *
jaroslav@601: *
- Since a proxy class implements all of the interfaces specified at
jaroslav@601: * its creation, invoking {@code getInterfaces} on its
jaroslav@601: * {@code Class} object will return an array containing the same
jaroslav@601: * list of interfaces (in the order specified at its creation), invoking
jaroslav@601: * {@code getMethods} on its {@code Class} object will return
jaroslav@601: * an array of {@code Method} objects that include all of the
jaroslav@601: * methods in those interfaces, and invoking {@code getMethod} will
jaroslav@601: * find methods in the proxy interfaces as would be expected.
jaroslav@601: *
jaroslav@601: *
- The {@link Proxy#isProxyClass Proxy.isProxyClass} method will
jaroslav@601: * return true if it is passed a proxy class-- a class returned by
jaroslav@601: * {@code Proxy.getProxyClass} or the class of an object returned by
jaroslav@601: * {@code Proxy.newProxyInstance}-- and false otherwise.
jaroslav@601: *
jaroslav@601: *
- The {@code java.security.ProtectionDomain} of a proxy class
jaroslav@601: * is the same as that of system classes loaded by the bootstrap class
jaroslav@601: * loader, such as {@code java.lang.Object}, because the code for a
jaroslav@601: * proxy class is generated by trusted system code. This protection
jaroslav@601: * domain will typically be granted
jaroslav@601: * {@code java.security.AllPermission}.
jaroslav@601: *
jaroslav@601: *
- Each proxy class has one public constructor that takes one argument,
jaroslav@601: * an implementation of the interface {@link InvocationHandler}, to set
jaroslav@601: * the invocation handler for a proxy instance. Rather than having to use
jaroslav@601: * the reflection API to access the public constructor, a proxy instance
jaroslav@601: * can be also be created by calling the {@link Proxy#newProxyInstance
jaroslav@601: * Proxy.newProxyInstance} method, which combines the actions of calling
jaroslav@601: * {@link Proxy#getProxyClass Proxy.getProxyClass} with invoking the
jaroslav@601: * constructor with an invocation handler.
jaroslav@601: *
jaroslav@601: *
jaroslav@601: * A proxy instance has the following properties:
jaroslav@601: *
jaroslav@601: *
jaroslav@601: *
jaroslav@601: * Methods Duplicated in Multiple Proxy Interfaces
jaroslav@601: *
jaroslav@601: * When two or more interfaces of a proxy class contain a method with
jaroslav@601: * the same name and parameter signature, the order of the proxy class's
jaroslav@601: * interfaces becomes significant. When such a duplicate method
jaroslav@601: * is invoked on a proxy instance, the {@code Method} object passed
jaroslav@601: * to the invocation handler will not necessarily be the one whose
jaroslav@601: * declaring class is assignable from the reference type of the interface
jaroslav@601: * that the proxy's method was invoked through. This limitation exists
jaroslav@601: * because the corresponding method implementation in the generated proxy
jaroslav@601: * class cannot determine which interface it was invoked through.
jaroslav@601: * Therefore, when a duplicate method is invoked on a proxy instance,
jaroslav@601: * the {@code Method} object for the method in the foremost interface
jaroslav@601: * that contains the method (either directly or inherited through a
jaroslav@601: * superinterface) in the proxy class's list of interfaces is passed to
jaroslav@601: * the invocation handler's {@code invoke} method, regardless of the
jaroslav@601: * reference type through which the method invocation occurred.
jaroslav@601: *
jaroslav@601: *
If a proxy interface contains a method with the same name and
jaroslav@601: * parameter signature as the {@code hashCode}, {@code equals},
jaroslav@601: * or {@code toString} methods of {@code java.lang.Object},
jaroslav@601: * when such a method is invoked on a proxy instance, the
jaroslav@601: * {@code Method} object passed to the invocation handler will have
jaroslav@601: * {@code java.lang.Object} as its declaring class. In other words,
jaroslav@601: * the public, non-final methods of {@code java.lang.Object}
jaroslav@601: * logically precede all of the proxy interfaces for the determination of
jaroslav@601: * which {@code Method} object to pass to the invocation handler.
jaroslav@601: *
jaroslav@601: *
Note also that when a duplicate method is dispatched to an
jaroslav@601: * invocation handler, the {@code invoke} method may only throw
jaroslav@601: * checked exception types that are assignable to one of the exception
jaroslav@601: * types in the {@code throws} clause of the method in all of
jaroslav@601: * the proxy interfaces that it can be invoked through. If the
jaroslav@601: * {@code invoke} method throws a checked exception that is not
jaroslav@601: * assignable to any of the exception types declared by the method in one
jaroslav@601: * of the proxy interfaces that it can be invoked through, then an
jaroslav@601: * unchecked {@code UndeclaredThrowableException} will be thrown by
jaroslav@601: * the invocation on the proxy instance. This restriction means that not
jaroslav@601: * all of the exception types returned by invoking
jaroslav@601: * {@code getExceptionTypes} on the {@code Method} object
jaroslav@601: * passed to the {@code invoke} method can necessarily be thrown
jaroslav@601: * successfully by the {@code invoke} method.
jaroslav@601: *
jaroslav@601: * @author Peter Jones
jaroslav@601: * @see InvocationHandler
jaroslav@601: * @since 1.3
jaroslav@601: */
jaroslav@1378: public final class ProxyImpl implements java.io.Serializable {
jaroslav@601:
jaroslav@601: private static final long serialVersionUID = -2222568056686623797L;
jaroslav@601:
jaroslav@1378: /** prefix for all proxy class names */
jaroslav@1378: private final static String proxyClassNamePrefix = "$Proxy";
jaroslav@601:
jaroslav@1378: /** parameter types of a proxy class constructor */
jaroslav@1378: private final static Class[] constructorParams =
jaroslav@1378: { InvocationHandler.class };
jaroslav@1378:
jaroslav@1378: /** maps a class loader to the proxy class cache for that loader */
jaroslav@1378: private static Map, Object>> loaderToCache
jaroslav@1378: = new WeakHashMap<>();
jaroslav@1378:
jaroslav@1378: /** marks that a particular proxy class is currently being generated */
jaroslav@1378: private static Object pendingGenerationMarker = new Object();
jaroslav@1378:
jaroslav@1378: /** next number to use for generation of unique proxy class names */
jaroslav@1378: private static long nextUniqueNumber = 0;
jaroslav@1378: private static Object nextUniqueNumberLock = new Object();
jaroslav@1378:
jaroslav@1378: /** set of all generated proxy classes, for isProxyClass implementation */
jaroslav@1378: private static Map, Void> proxyClasses =
jaroslav@1378: Collections.synchronizedMap(new WeakHashMap, Void>());
jaroslav@601:
jaroslav@601: /**
jaroslav@601: * the invocation handler for this proxy instance.
jaroslav@601: * @serial
jaroslav@601: */
jaroslav@601: protected InvocationHandler h;
jaroslav@601:
jaroslav@601: /**
jaroslav@601: * Prohibits instantiation.
jaroslav@601: */
jaroslav@1378: private ProxyImpl() {
jaroslav@601: }
jaroslav@601:
jaroslav@601: /**
jaroslav@601: * Constructs a new {@code Proxy} instance from a subclass
jaroslav@601: * (typically, a dynamic proxy class) with the specified value
jaroslav@601: * for its invocation handler.
jaroslav@601: *
jaroslav@601: * @param h the invocation handler for this proxy instance
jaroslav@601: */
jaroslav@1378: protected ProxyImpl(InvocationHandler h) {
jaroslav@601: this.h = h;
jaroslav@601: }
jaroslav@601:
jaroslav@601: /**
jaroslav@601: * Returns the {@code java.lang.Class} object for a proxy class
jaroslav@601: * given a class loader and an array of interfaces. The proxy class
jaroslav@601: * will be defined by the specified class loader and will implement
jaroslav@601: * all of the supplied interfaces. If a proxy class for the same
jaroslav@601: * permutation of interfaces has already been defined by the class
jaroslav@601: * loader, then the existing proxy class will be returned; otherwise,
jaroslav@601: * a proxy class for those interfaces will be generated dynamically
jaroslav@601: * and defined by the class loader.
jaroslav@601: *
jaroslav@601: * There are several restrictions on the parameters that may be
jaroslav@601: * passed to {@code Proxy.getProxyClass}:
jaroslav@601: *
jaroslav@601: *
jaroslav@601: *
jaroslav@601: * If any of these restrictions are violated,
jaroslav@601: * {@code Proxy.getProxyClass} will throw an
jaroslav@601: * {@code IllegalArgumentException}. If the {@code interfaces}
jaroslav@601: * array argument or any of its elements are {@code null}, a
jaroslav@601: * {@code NullPointerException} will be thrown.
jaroslav@601: *
jaroslav@601: *
Note that the order of the specified proxy interfaces is
jaroslav@601: * significant: two requests for a proxy class with the same combination
jaroslav@601: * of interfaces but in a different order will result in two distinct
jaroslav@601: * proxy classes.
jaroslav@601: *
jaroslav@601: * @param loader the class loader to define the proxy class
jaroslav@601: * @param interfaces the list of interfaces for the proxy class
jaroslav@601: * to implement
jaroslav@601: * @return a proxy class that is defined in the specified class loader
jaroslav@601: * and that implements the specified interfaces
jaroslav@601: * @throws IllegalArgumentException if any of the restrictions on the
jaroslav@601: * parameters that may be passed to {@code getProxyClass}
jaroslav@601: * are violated
jaroslav@601: * @throws NullPointerException if the {@code interfaces} array
jaroslav@601: * argument or any of its elements are {@code null}
jaroslav@601: */
jaroslav@601: public static Class getProxyClass(ClassLoader loader,
jaroslav@601: Class... interfaces)
jaroslav@601: throws IllegalArgumentException
jaroslav@601: {
jaroslav@1378: if (interfaces.length > 65535) {
jaroslav@1378: throw new IllegalArgumentException("interface limit exceeded");
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: Class proxyClass = null;
jaroslav@1378:
jaroslav@1378: /* collect interface names to use as key for proxy class cache */
jaroslav@1378: String[] interfaceNames = new String[interfaces.length];
jaroslav@1378:
jaroslav@1378: // for detecting duplicates
jaroslav@1378: Set> interfaceSet = new HashSet<>();
jaroslav@1378:
jaroslav@1378: for (int i = 0; i < interfaces.length; i++) {
jaroslav@1378: /*
jaroslav@1378: * Verify that the class loader resolves the name of this
jaroslav@1378: * interface to the same Class object.
jaroslav@1378: */
jaroslav@1378: String interfaceName = interfaces[i].getName();
jaroslav@1378: Class interfaceClass = null;
jaroslav@1378: try {
jaroslav@1378: interfaceClass = Class.forName(interfaceName, false, loader);
jaroslav@1378: } catch (ClassNotFoundException e) {
jaroslav@1378: }
jaroslav@1378: if (interfaceClass != interfaces[i]) {
jaroslav@1378: throw new IllegalArgumentException(
jaroslav@1378: interfaces[i] + " is not visible from class loader");
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Verify that the Class object actually represents an
jaroslav@1378: * interface.
jaroslav@1378: */
jaroslav@1378: if (!interfaceClass.isInterface()) {
jaroslav@1378: throw new IllegalArgumentException(
jaroslav@1378: interfaceClass.getName() + " is not an interface");
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Verify that this interface is not a duplicate.
jaroslav@1378: */
jaroslav@1378: if (interfaceSet.contains(interfaceClass)) {
jaroslav@1378: throw new IllegalArgumentException(
jaroslav@1378: "repeated interface: " + interfaceClass.getName());
jaroslav@1378: }
jaroslav@1378: interfaceSet.add(interfaceClass);
jaroslav@1378:
jaroslav@1378: interfaceNames[i] = interfaceName;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Using string representations of the proxy interfaces as
jaroslav@1378: * keys in the proxy class cache (instead of their Class
jaroslav@1378: * objects) is sufficient because we require the proxy
jaroslav@1378: * interfaces to be resolvable by name through the supplied
jaroslav@1378: * class loader, and it has the advantage that using a string
jaroslav@1378: * representation of a class makes for an implicit weak
jaroslav@1378: * reference to the class.
jaroslav@1378: */
jaroslav@1378: List key = Arrays.asList(interfaceNames);
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Find or create the proxy class cache for the class loader.
jaroslav@1378: */
jaroslav@1378: Map, Object> cache;
jaroslav@1378: synchronized (loaderToCache) {
jaroslav@1378: cache = loaderToCache.get(loader);
jaroslav@1378: if (cache == null) {
jaroslav@1378: cache = new HashMap<>();
jaroslav@1378: loaderToCache.put(loader, cache);
jaroslav@1378: }
jaroslav@1378: /*
jaroslav@1378: * This mapping will remain valid for the duration of this
jaroslav@1378: * method, without further synchronization, because the mapping
jaroslav@1378: * will only be removed if the class loader becomes unreachable.
jaroslav@1378: */
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Look up the list of interfaces in the proxy class cache using
jaroslav@1378: * the key. This lookup will result in one of three possible
jaroslav@1378: * kinds of values:
jaroslav@1378: * null, if there is currently no proxy class for the list of
jaroslav@1378: * interfaces in the class loader,
jaroslav@1378: * the pendingGenerationMarker object, if a proxy class for the
jaroslav@1378: * list of interfaces is currently being generated,
jaroslav@1378: * or a weak reference to a Class object, if a proxy class for
jaroslav@1378: * the list of interfaces has already been generated.
jaroslav@1378: */
jaroslav@1378: synchronized (cache) {
jaroslav@1378: /*
jaroslav@1378: * Note that we need not worry about reaping the cache for
jaroslav@1378: * entries with cleared weak references because if a proxy class
jaroslav@1378: * has been garbage collected, its class loader will have been
jaroslav@1378: * garbage collected as well, so the entire cache will be reaped
jaroslav@1378: * from the loaderToCache map.
jaroslav@1378: */
jaroslav@1378: do {
jaroslav@1378: Object value = cache.get(key);
jaroslav@1378: if (value instanceof Reference) {
jaroslav@1378: proxyClass = (Class) ((Reference) value).get();
jaroslav@1378: }
jaroslav@1378: if (proxyClass != null) {
jaroslav@1378: // proxy class already generated: return it
jaroslav@1378: return proxyClass;
jaroslav@1378: } else if (value == pendingGenerationMarker) {
jaroslav@1378: // proxy class being generated: wait for it
jaroslav@1378: try {
jaroslav@1378: cache.wait();
jaroslav@1378: } catch (InterruptedException e) {
jaroslav@1378: /*
jaroslav@1378: * The class generation that we are waiting for should
jaroslav@1378: * take a small, bounded time, so we can safely ignore
jaroslav@1378: * thread interrupts here.
jaroslav@1378: */
jaroslav@1378: }
jaroslav@1378: continue;
jaroslav@1378: } else {
jaroslav@1378: /*
jaroslav@1378: * No proxy class for this list of interfaces has been
jaroslav@1378: * generated or is being generated, so we will go and
jaroslav@1378: * generate it now. Mark it as pending generation.
jaroslav@1378: */
jaroslav@1378: cache.put(key, pendingGenerationMarker);
jaroslav@1378: break;
jaroslav@1378: }
jaroslav@1378: } while (true);
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: try {
jaroslav@1378: String proxyPkg = null; // package to define proxy class in
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Record the package of a non-public proxy interface so that the
jaroslav@1378: * proxy class will be defined in the same package. Verify that
jaroslav@1378: * all non-public proxy interfaces are in the same package.
jaroslav@1378: */
jaroslav@1378: for (int i = 0; i < interfaces.length; i++) {
jaroslav@1378: int flags = interfaces[i].getModifiers();
jaroslav@1378: if (!Modifier.isPublic(flags)) {
jaroslav@1378: String name = interfaces[i].getName();
jaroslav@1378: int n = name.lastIndexOf('.');
jaroslav@1378: String pkg = ((n == -1) ? "" : name.substring(0, n + 1));
jaroslav@1378: if (proxyPkg == null) {
jaroslav@1378: proxyPkg = pkg;
jaroslav@1378: } else if (!pkg.equals(proxyPkg)) {
jaroslav@1378: throw new IllegalArgumentException(
jaroslav@1378: "non-public interfaces from different packages");
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: if (proxyPkg == null) { // if no non-public proxy interfaces,
jaroslav@1378: proxyPkg = ""; // use the unnamed package
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: {
jaroslav@1378: /*
jaroslav@1378: * Choose a name for the proxy class to generate.
jaroslav@1378: */
jaroslav@1378: long num;
jaroslav@1378: synchronized (nextUniqueNumberLock) {
jaroslav@1378: num = nextUniqueNumber++;
jaroslav@1378: }
jaroslav@1378: String proxyName = proxyPkg + proxyClassNamePrefix + num;
jaroslav@1378: /*
jaroslav@1378: * Verify that the class loader hasn't already
jaroslav@1378: * defined a class with the chosen name.
jaroslav@1378: */
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Generate the specified proxy class.
jaroslav@1378: */
jaroslav@1378: Generator gen = new Generator(proxyName, interfaces);
jaroslav@1378: final byte[] proxyClassFile = gen.generateClassFile();
jaroslav@1378: try {
jaroslav@1378: proxyClass = defineClass0(loader, proxyName,
jaroslav@1378: proxyClassFile);
jaroslav@1378: } catch (ClassFormatError e) {
jaroslav@1378: /*
jaroslav@1378: * A ClassFormatError here means that (barring bugs in the
jaroslav@1378: * proxy class generation code) there was some other
jaroslav@1378: * invalid aspect of the arguments supplied to the proxy
jaroslav@1378: * class creation (such as virtual machine limitations
jaroslav@1378: * exceeded).
jaroslav@1378: */
jaroslav@1378: throw new IllegalArgumentException(e.toString());
jaroslav@1378: }
jaroslav@1378: gen.fillInMethods(proxyClass);
jaroslav@1378: }
jaroslav@1378: // add to set of all generated proxy classes, for isProxyClass
jaroslav@1378: proxyClasses.put(proxyClass, null);
jaroslav@1378:
jaroslav@1378: } finally {
jaroslav@1378: /*
jaroslav@1378: * We must clean up the "pending generation" state of the proxy
jaroslav@1378: * class cache entry somehow. If a proxy class was successfully
jaroslav@1378: * generated, store it in the cache (with a weak reference);
jaroslav@1378: * otherwise, remove the reserved entry. In all cases, notify
jaroslav@1378: * all waiters on reserved entries in this cache.
jaroslav@1378: */
jaroslav@1378: synchronized (cache) {
jaroslav@1378: if (proxyClass != null) {
jaroslav@1378: cache.put(key, new WeakReference>(proxyClass));
jaroslav@1378: } else {
jaroslav@1378: cache.remove(key);
jaroslav@1378: }
jaroslav@1378: cache.notifyAll();
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: return proxyClass;
jaroslav@601: }
jaroslav@601:
jaroslav@601: /**
jaroslav@601: * Returns an instance of a proxy class for the specified interfaces
jaroslav@601: * that dispatches method invocations to the specified invocation
jaroslav@601: * handler. This method is equivalent to:
jaroslav@601: *
jaroslav@601: * Proxy.getProxyClass(loader, interfaces).
jaroslav@601: * getConstructor(new Class[] { InvocationHandler.class }).
jaroslav@601: * newInstance(new Object[] { handler });
jaroslav@601: *
jaroslav@601: *
jaroslav@601: * {@code Proxy.newProxyInstance} throws
jaroslav@601: * {@code IllegalArgumentException} for the same reasons that
jaroslav@601: * {@code Proxy.getProxyClass} does.
jaroslav@601: *
jaroslav@601: * @param loader the class loader to define the proxy class
jaroslav@601: * @param interfaces the list of interfaces for the proxy class
jaroslav@601: * to implement
jaroslav@601: * @param h the invocation handler to dispatch method invocations to
jaroslav@601: * @return a proxy instance with the specified invocation handler of a
jaroslav@601: * proxy class that is defined by the specified class loader
jaroslav@601: * and that implements the specified interfaces
jaroslav@601: * @throws IllegalArgumentException if any of the restrictions on the
jaroslav@601: * parameters that may be passed to {@code getProxyClass}
jaroslav@601: * are violated
jaroslav@601: * @throws NullPointerException if the {@code interfaces} array
jaroslav@601: * argument or any of its elements are {@code null}, or
jaroslav@601: * if the invocation handler, {@code h}, is
jaroslav@601: * {@code null}
jaroslav@601: */
jaroslav@601: public static Object newProxyInstance(ClassLoader loader,
jaroslav@601: Class[] interfaces,
jaroslav@601: InvocationHandler h)
jaroslav@601: throws IllegalArgumentException
jaroslav@601: {
jaroslav@601: if (h == null) {
jaroslav@601: throw new NullPointerException();
jaroslav@601: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Look up or generate the designated proxy class.
jaroslav@1378: */
jaroslav@1378: Class cl = getProxyClass(loader, interfaces);
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Invoke its constructor with the designated invocation handler.
jaroslav@1378: */
jaroslav@1378: try {
jaroslav@1378: Constructor cons = cl.getConstructor(constructorParams);
jaroslav@1378: return cons.newInstance(new Object[] { h });
jaroslav@1378: } catch (NoSuchMethodException e) {
jaroslav@1378: throw new InternalError(e.toString());
jaroslav@1378: } catch (IllegalAccessException e) {
jaroslav@1378: throw new InternalError(e.toString());
jaroslav@1378: } catch (InstantiationException e) {
jaroslav@1378: throw new InternalError(e.toString());
jaroslav@1378: } catch (InvocationTargetException e) {
jaroslav@1378: throw new InternalError(e.toString());
jaroslav@1378: }
jaroslav@601: }
jaroslav@601:
jaroslav@601: /**
jaroslav@601: * Returns true if and only if the specified class was dynamically
jaroslav@601: * generated to be a proxy class using the {@code getProxyClass}
jaroslav@601: * method or the {@code newProxyInstance} method.
jaroslav@601: *
jaroslav@601: *
The reliability of this method is important for the ability
jaroslav@601: * to use it to make security decisions, so its implementation should
jaroslav@601: * not just test if the class in question extends {@code Proxy}.
jaroslav@601: *
jaroslav@601: * @param cl the class to test
jaroslav@601: * @return {@code true} if the class is a proxy class and
jaroslav@601: * {@code false} otherwise
jaroslav@601: * @throws NullPointerException if {@code cl} is {@code null}
jaroslav@601: */
jaroslav@601: public static boolean isProxyClass(Class cl) {
jaroslav@601: if (cl == null) {
jaroslav@601: throw new NullPointerException();
jaroslav@601: }
jaroslav@601:
jaroslav@1378: return proxyClasses.containsKey(cl);
jaroslav@601: }
jaroslav@601:
jaroslav@601: /**
jaroslav@601: * Returns the invocation handler for the specified proxy instance.
jaroslav@601: *
jaroslav@601: * @param proxy the proxy instance to return the invocation handler for
jaroslav@601: * @return the invocation handler for the proxy instance
jaroslav@601: * @throws IllegalArgumentException if the argument is not a
jaroslav@601: * proxy instance
jaroslav@601: */
jaroslav@601: public static InvocationHandler getInvocationHandler(Object proxy)
jaroslav@601: throws IllegalArgumentException
jaroslav@601: {
jaroslav@601: /*
jaroslav@601: * Verify that the object is actually a proxy instance.
jaroslav@601: */
jaroslav@601: if (!isProxyClass(proxy.getClass())) {
jaroslav@601: throw new IllegalArgumentException("not a proxy instance");
jaroslav@601: }
jaroslav@601:
jaroslav@1378: ProxyImpl p = (ProxyImpl) proxy;
jaroslav@601: return p.h;
jaroslav@601: }
jaroslav@601:
jaroslav@1378: @JavaScriptBody(args = { "ignore", "name", "byteCode" },
jaroslav@1378: body = "return vm._reload(name, byteCode).constructor.$class;"
jaroslav@1378: )
jaroslav@1378: private static native Class defineClass0(
jaroslav@1378: ClassLoader loader, String name, byte[] b
jaroslav@1378: );
jaroslav@1378:
jaroslav@1378: private static class Generator {
jaroslav@1378: /*
jaroslav@1378: * In the comments below, "JVMS" refers to The Java Virtual Machine
jaroslav@1378: * Specification Second Edition and "JLS" refers to the original
jaroslav@1378: * version of The Java Language Specification, unless otherwise
jaroslav@1378: * specified.
jaroslav@1378: */
jaroslav@1378:
jaroslav@1378: /* need 1.6 bytecode */
jaroslav@1378: private static final int CLASSFILE_MAJOR_VERSION = 50;
jaroslav@1378: private static final int CLASSFILE_MINOR_VERSION = 0;
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * beginning of constants copied from
jaroslav@1378: * sun.tools.java.RuntimeConstants (which no longer exists):
jaroslav@1378: */
jaroslav@1378:
jaroslav@1378: /* constant pool tags */
jaroslav@1378: private static final int CONSTANT_UTF8 = 1;
jaroslav@1378: private static final int CONSTANT_UNICODE = 2;
jaroslav@1378: private static final int CONSTANT_INTEGER = 3;
jaroslav@1378: private static final int CONSTANT_FLOAT = 4;
jaroslav@1378: private static final int CONSTANT_LONG = 5;
jaroslav@1378: private static final int CONSTANT_DOUBLE = 6;
jaroslav@1378: private static final int CONSTANT_CLASS = 7;
jaroslav@1378: private static final int CONSTANT_STRING = 8;
jaroslav@1378: private static final int CONSTANT_FIELD = 9;
jaroslav@1378: private static final int CONSTANT_METHOD = 10;
jaroslav@1378: private static final int CONSTANT_INTERFACEMETHOD = 11;
jaroslav@1378: private static final int CONSTANT_NAMEANDTYPE = 12;
jaroslav@1378:
jaroslav@1378: /* access and modifier flags */
jaroslav@1378: private static final int ACC_PUBLIC = 0x00000001;
jaroslav@1378: private static final int ACC_FINAL = 0x00000010;
jaroslav@1378: private static final int ACC_SUPER = 0x00000020;
jaroslav@1378:
jaroslav@1378: // end of constants copied from sun.tools.java.RuntimeConstants
jaroslav@1378: /**
jaroslav@1378: * name of the superclass of proxy classes
jaroslav@1378: */
jaroslav@1378: private final static String superclassName = "java/lang/reflect/Proxy";
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * name of field for storing a proxy instance's invocation handler
jaroslav@1378: */
jaroslav@1378: private final static String handlerFieldName = "h";
jaroslav@1378:
jaroslav@1378: /* preloaded Method objects for methods in java.lang.Object */
jaroslav@1378: private static Method hashCodeMethod;
jaroslav@1378: private static Method equalsMethod;
jaroslav@1378: private static Method toStringMethod;
jaroslav@1378:
jaroslav@1378: static {
jaroslav@1378: try {
jaroslav@1378: hashCodeMethod = Object.class.getMethod("hashCode");
jaroslav@1378: equalsMethod
jaroslav@1378: = Object.class.getMethod("equals", new Class[]{Object.class});
jaroslav@1378: toStringMethod = Object.class.getMethod("toString");
jaroslav@1378: } catch (NoSuchMethodException e) {
jaroslav@1378: throw new IllegalStateException(e.getMessage());
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * name of proxy class
jaroslav@1378: */
jaroslav@1378: private String className;
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * proxy interfaces
jaroslav@1378: */
jaroslav@1378: private Class[] interfaces;
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * constant pool of class being generated
jaroslav@1378: */
jaroslav@1378: private ConstantPool cp = new ConstantPool();
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * maps method signature string to list of ProxyMethod objects for proxy
jaroslav@1378: * methods with that signature
jaroslav@1378: */
jaroslav@1378: private Map> proxyMethods
jaroslav@1378: = new HashMap>();
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * count of ProxyMethod objects added to proxyMethods
jaroslav@1378: */
jaroslav@1378: private int proxyMethodCount = 0;
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Construct a ProxyGenerator to generate a proxy class with the
jaroslav@1378: * specified name and for the given interfaces.
jaroslav@1378: *
jaroslav@1378: * A ProxyGenerator object contains the state for the ongoing generation
jaroslav@1378: * of a particular proxy class.
jaroslav@1378: */
jaroslav@1378: private Generator(String className, Class[] interfaces) {
jaroslav@1378: this.className = className;
jaroslav@1378: this.interfaces = interfaces;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Generate a class file for the proxy class. This method drives the
jaroslav@1378: * class file generation process.
jaroslav@1378: */
jaroslav@1378: private byte[] generateClassFile() {
jaroslav@1378:
jaroslav@1378: /* ============================================================
jaroslav@1378: * Step 1: Assemble ProxyMethod objects for all methods to
jaroslav@1378: * generate proxy dispatching code for.
jaroslav@1378: */
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Record that proxy methods are needed for the hashCode, equals,
jaroslav@1378: * and toString methods of java.lang.Object. This is done before
jaroslav@1378: * the methods from the proxy interfaces so that the methods from
jaroslav@1378: * java.lang.Object take precedence over duplicate methods in the
jaroslav@1378: * proxy interfaces.
jaroslav@1378: */
jaroslav@1378: addProxyMethod(hashCodeMethod, Object.class);
jaroslav@1378: addProxyMethod(equalsMethod, Object.class);
jaroslav@1378: addProxyMethod(toStringMethod, Object.class);
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Now record all of the methods from the proxy interfaces, giving
jaroslav@1378: * earlier interfaces precedence over later ones with duplicate
jaroslav@1378: * methods.
jaroslav@1378: */
jaroslav@1378: for (int i = 0; i < interfaces.length; i++) {
jaroslav@1378: Method[] methods = interfaces[i].getMethods();
jaroslav@1378: for (int j = 0; j < methods.length; j++) {
jaroslav@1378: addProxyMethod(methods[j], interfaces[i]);
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * For each set of proxy methods with the same signature,
jaroslav@1378: * verify that the methods' return types are compatible.
jaroslav@1378: */
jaroslav@1378: for (List sigmethods : proxyMethods.values()) {
jaroslav@1378: checkReturnTypes(sigmethods);
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /* ============================================================
jaroslav@1378: * Step 2: Assemble FieldInfo and MethodInfo structs for all of
jaroslav@1378: * fields and methods in the class we are generating.
jaroslav@1378: */
jaroslav@1378:
jaroslav@1378: // will be done in fillInMethods
jaroslav@1378:
jaroslav@1378: /* ============================================================
jaroslav@1378: * Step 3: Write the final class file.
jaroslav@1378: */
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Make sure that constant pool indexes are reserved for the
jaroslav@1378: * following items before starting to write the final class file.
jaroslav@1378: */
jaroslav@1378: cp.getClass(dotToSlash(className));
jaroslav@1378: cp.getClass(superclassName);
jaroslav@1378: for (int i = 0; i < interfaces.length; i++) {
jaroslav@1378: cp.getClass(dotToSlash(interfaces[i].getName()));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Disallow new constant pool additions beyond this point, since
jaroslav@1378: * we are about to write the final constant pool table.
jaroslav@1378: */
jaroslav@1378: cp.setReadOnly();
jaroslav@1378:
jaroslav@1378: ByteArrayOutputStream bout = new ByteArrayOutputStream();
jaroslav@1378: DataOutputStream dout = new DataOutputStream(bout);
jaroslav@1378:
jaroslav@1378: try {
jaroslav@1378: /*
jaroslav@1378: * Write all the items of the "ClassFile" structure.
jaroslav@1378: * See JVMS section 4.1.
jaroslav@1378: */
jaroslav@1378: // u4 magic;
jaroslav@1378: dout.writeInt(0xCAFEBABE);
jaroslav@1378: // u2 minor_version;
jaroslav@1378: dout.writeShort(CLASSFILE_MINOR_VERSION);
jaroslav@1378: // u2 major_version;
jaroslav@1378: dout.writeShort(CLASSFILE_MAJOR_VERSION);
jaroslav@1378:
jaroslav@1378: cp.write(dout); // (write constant pool)
jaroslav@1378:
jaroslav@1378: // u2 access_flags;
jaroslav@1378: dout.writeShort(ACC_PUBLIC | ACC_FINAL | ACC_SUPER);
jaroslav@1378: // u2 this_class;
jaroslav@1378: dout.writeShort(cp.getClass(dotToSlash(className)));
jaroslav@1378: // u2 super_class;
jaroslav@1378: dout.writeShort(cp.getClass(superclassName));
jaroslav@1378:
jaroslav@1378: // u2 interfaces_count;
jaroslav@1378: dout.writeShort(interfaces.length);
jaroslav@1378: // u2 interfaces[interfaces_count];
jaroslav@1378: for (int i = 0; i < interfaces.length; i++) {
jaroslav@1378: dout.writeShort(cp.getClass(
jaroslav@1378: dotToSlash(interfaces[i].getName())));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: // u2 fields_count;
jaroslav@1378: dout.writeShort(0);
jaroslav@1378:
jaroslav@1378: // u2 methods_count;
jaroslav@1378: dout.writeShort(0);
jaroslav@1378:
jaroslav@1378: // u2 attributes_count;
jaroslav@1378: dout.writeShort(0); // (no ClassFile attributes for proxy classes)
jaroslav@1378:
jaroslav@1378: } catch (IOException e) {
jaroslav@1378: throw new InternalError("unexpected I/O Exception");
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: return bout.toByteArray();
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: @JavaScriptBody(args = { "c", "sig", "method", "primitive" }, body =
jaroslav@1378: "var p = c.cnstr.prototype;\n" +
jaroslav@1378: "p[sig] = function() {\n" +
jaroslav@1378: " var h = this._h();\n" +
jaroslav@1378: " var res = h.invoke__Ljava_lang_Object_2Ljava_lang_Object_2Ljava_lang_reflect_Method_2_3Ljava_lang_Object_2(this, method, arguments);\n" +
jaroslav@1378: " \n" +
jaroslav@1378: " \n" +
jaroslav@1378: " return res;\n" +
jaroslav@1378: "};"
jaroslav@1378: )
jaroslav@1378: private static native void defineMethod(Class proxyClass, String sig, Method method, boolean primitive);
jaroslav@1378:
jaroslav@1378: @JavaScriptBody(args = "c", body =
jaroslav@1378: "var h = c.cnstr.cons__VLjava_lang_reflect_InvocationHandler_2 = function(h) {\n"
jaroslav@1378: + " c.superclass.cnstr.cons__VLjava_lang_reflect_InvocationHandler_2.call(this, h);\n"
jaroslav@1378: + "}\n"
jaroslav@1378: + "h.cls = c.cnstr;\n"
jaroslav@1378: )
jaroslav@1378: private static native void defineConstructor(Class proxyClass);
jaroslav@1378:
jaroslav@1378: final void fillInMethods(Class proxyClass) {
jaroslav@1378: for (List sigmethods : proxyMethods.values()) {
jaroslav@1378: for (ProxyMethod pm : sigmethods) {
jaroslav@1378: String sig = MethodImpl.toSignature(pm.method);
jaroslav@1378: defineMethod(proxyClass, sig, pm.method, pm.method.getReturnType().isPrimitive());
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: defineConstructor(proxyClass);
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Add another method to be proxied, either by creating a new
jaroslav@1378: * ProxyMethod object or augmenting an old one for a duplicate method.
jaroslav@1378: *
jaroslav@1378: * "fromClass" indicates the proxy interface that the method was found
jaroslav@1378: * through, which may be different from (a subinterface of) the method's
jaroslav@1378: * "declaring class". Note that the first Method object passed for a
jaroslav@1378: * given name and descriptor identifies the Method object (and thus the
jaroslav@1378: * declaring class) that will be passed to the invocation handler's
jaroslav@1378: * "invoke" method for a given set of duplicate methods.
jaroslav@1378: */
jaroslav@1378: private void addProxyMethod(Method m, Class fromClass) {
jaroslav@1378: String name = m.getName();
jaroslav@1378: Class[] parameterTypes = m.getParameterTypes();
jaroslav@1378: Class returnType = m.getReturnType();
jaroslav@1378: Class[] exceptionTypes = m.getExceptionTypes();
jaroslav@1378:
jaroslav@1378: String sig = MethodImpl.toSignature(m);
jaroslav@1378: List sigmethods = proxyMethods.get(sig);
jaroslav@1378: if (sigmethods != null) {
jaroslav@1378: for (ProxyMethod pm : sigmethods) {
jaroslav@1378: if (returnType == pm.returnType) {
jaroslav@1378: /*
jaroslav@1378: * Found a match: reduce exception types to the
jaroslav@1378: * greatest set of exceptions that can thrown
jaroslav@1378: * compatibly with the throws clauses of both
jaroslav@1378: * overridden methods.
jaroslav@1378: */
jaroslav@1378: List> legalExceptions = new ArrayList>();
jaroslav@1378: collectCompatibleTypes(
jaroslav@1378: exceptionTypes, pm.exceptionTypes, legalExceptions);
jaroslav@1378: collectCompatibleTypes(
jaroslav@1378: pm.exceptionTypes, exceptionTypes, legalExceptions);
jaroslav@1378: pm.exceptionTypes = new Class[legalExceptions.size()];
jaroslav@1378: pm.exceptionTypes
jaroslav@1378: = legalExceptions.toArray(pm.exceptionTypes);
jaroslav@1378: return;
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: } else {
jaroslav@1378: sigmethods = new ArrayList(3);
jaroslav@1378: proxyMethods.put(sig, sigmethods);
jaroslav@1378: }
jaroslav@1378: sigmethods.add(new ProxyMethod(m, name, parameterTypes, returnType,
jaroslav@1378: exceptionTypes, fromClass));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * For a given set of proxy methods with the same signature, check that
jaroslav@1378: * their return types are compatible according to the Proxy
jaroslav@1378: * specification.
jaroslav@1378: *
jaroslav@1378: * Specifically, if there is more than one such method, then all of the
jaroslav@1378: * return types must be reference types, and there must be one return
jaroslav@1378: * type that is assignable to each of the rest of them.
jaroslav@1378: */
jaroslav@1378: private static void checkReturnTypes(List methods) {
jaroslav@1378: /*
jaroslav@1378: * If there is only one method with a given signature, there
jaroslav@1378: * cannot be a conflict. This is the only case in which a
jaroslav@1378: * primitive (or void) return type is allowed.
jaroslav@1378: */
jaroslav@1378: if (methods.size() < 2) {
jaroslav@1378: return;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * List of return types that are not yet known to be
jaroslav@1378: * assignable from ("covered" by) any of the others.
jaroslav@1378: */
jaroslav@1378: LinkedList> uncoveredReturnTypes = new LinkedList>();
jaroslav@1378:
jaroslav@1378: nextNewReturnType:
jaroslav@1378: for (ProxyMethod pm : methods) {
jaroslav@1378: Class newReturnType = pm.returnType;
jaroslav@1378: if (newReturnType.isPrimitive()) {
jaroslav@1378: throw new IllegalArgumentException(
jaroslav@1378: "methods with same signature "
jaroslav@1378: + getFriendlyMethodSignature(pm.methodName,
jaroslav@1378: pm.parameterTypes)
jaroslav@1378: + " but incompatible return types: "
jaroslav@1378: + newReturnType.getName() + " and others");
jaroslav@1378: }
jaroslav@1378: boolean added = false;
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * Compare the new return type to the existing uncovered
jaroslav@1378: * return types.
jaroslav@1378: */
jaroslav@1378: ListIterator> liter = uncoveredReturnTypes.listIterator();
jaroslav@1378: while (liter.hasNext()) {
jaroslav@1378: Class uncoveredReturnType = liter.next();
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * If an existing uncovered return type is assignable
jaroslav@1378: * to this new one, then we can forget the new one.
jaroslav@1378: */
jaroslav@1378: if (newReturnType.isAssignableFrom(uncoveredReturnType)) {
jaroslav@1378: assert !added;
jaroslav@1378: continue nextNewReturnType;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * If the new return type is assignable to an existing
jaroslav@1378: * uncovered one, then should replace the existing one
jaroslav@1378: * with the new one (or just forget the existing one,
jaroslav@1378: * if the new one has already be put in the list).
jaroslav@1378: */
jaroslav@1378: if (uncoveredReturnType.isAssignableFrom(newReturnType)) {
jaroslav@1378: // (we can assume that each return type is unique)
jaroslav@1378: if (!added) {
jaroslav@1378: liter.set(newReturnType);
jaroslav@1378: added = true;
jaroslav@1378: } else {
jaroslav@1378: liter.remove();
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * If we got through the list of existing uncovered return
jaroslav@1378: * types without an assignability relationship, then add
jaroslav@1378: * the new return type to the list of uncovered ones.
jaroslav@1378: */
jaroslav@1378: if (!added) {
jaroslav@1378: uncoveredReturnTypes.add(newReturnType);
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * We shouldn't end up with more than one return type that is
jaroslav@1378: * not assignable from any of the others.
jaroslav@1378: */
jaroslav@1378: if (uncoveredReturnTypes.size() > 1) {
jaroslav@1378: ProxyMethod pm = methods.get(0);
jaroslav@1378: throw new IllegalArgumentException(
jaroslav@1378: "methods with same signature "
jaroslav@1378: + getFriendlyMethodSignature(pm.methodName, pm.parameterTypes)
jaroslav@1378: + " but incompatible return types: " + uncoveredReturnTypes);
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * A ProxyMethod object represents a proxy method in the proxy class
jaroslav@1378: * being generated: a method whose implementation will encode and
jaroslav@1378: * dispatch invocations to the proxy instance's invocation handler.
jaroslav@1378: */
jaroslav@1378: private class ProxyMethod {
jaroslav@1378:
jaroslav@1378: private final Method method;
jaroslav@1378: public String methodName;
jaroslav@1378: public Class[] parameterTypes;
jaroslav@1378: public Class returnType;
jaroslav@1378: public Class[] exceptionTypes;
jaroslav@1378: public Class fromClass;
jaroslav@1378: public String methodFieldName;
jaroslav@1378:
jaroslav@1378: private ProxyMethod(Method m,
jaroslav@1378: String methodName, Class[] parameterTypes,
jaroslav@1378: Class returnType, Class[] exceptionTypes,
jaroslav@1378: Class fromClass
jaroslav@1378: ) {
jaroslav@1378: this.method = m;
jaroslav@1378: this.methodName = methodName;
jaroslav@1378: this.parameterTypes = parameterTypes;
jaroslav@1378: this.returnType = returnType;
jaroslav@1378: this.exceptionTypes = exceptionTypes;
jaroslav@1378: this.fromClass = fromClass;
jaroslav@1378: this.methodFieldName = "m" + proxyMethodCount++;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /*
jaroslav@1378: * ==================== General Utility Methods ====================
jaroslav@1378: */
jaroslav@1378: /**
jaroslav@1378: * Convert a fully qualified class name that uses '.' as the package
jaroslav@1378: * separator, the external representation used by the Java language and
jaroslav@1378: * APIs, to a fully qualified class name that uses '/' as the package
jaroslav@1378: * separator, the representation used in the class file format (see JVMS
jaroslav@1378: * section 4.2).
jaroslav@1378: */
jaroslav@1378: private static String dotToSlash(String name) {
jaroslav@1378: return name.replace('.', '/');
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Return the list of "parameter descriptor" strings enclosed in
jaroslav@1378: * parentheses corresponding to the given parameter types (in other
jaroslav@1378: * words, a method descriptor without a return descriptor). This string
jaroslav@1378: * is useful for constructing string keys for methods without regard to
jaroslav@1378: * their return type.
jaroslav@1378: */
jaroslav@1378: private static String getParameterDescriptors(Class[] parameterTypes) {
jaroslav@1378: StringBuilder desc = new StringBuilder("(");
jaroslav@1378: for (int i = 0; i < parameterTypes.length; i++) {
jaroslav@1378: desc.append(getFieldType(parameterTypes[i]));
jaroslav@1378: }
jaroslav@1378: desc.append(')');
jaroslav@1378: return desc.toString();
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Return the "field type" string for the given type, appropriate for a
jaroslav@1378: * field descriptor, a parameter descriptor, or a return descriptor
jaroslav@1378: * other than "void". See JVMS section 4.3.2.
jaroslav@1378: */
jaroslav@1378: private static String getFieldType(Class type) {
jaroslav@1378: if (type.isPrimitive()) {
jaroslav@1378: return PrimitiveTypeInfo.get(type).baseTypeString;
jaroslav@1378: } else if (type.isArray()) {
jaroslav@1378: /*
jaroslav@1378: * According to JLS 20.3.2, the getName() method on Class does
jaroslav@1378: * return the VM type descriptor format for array classes (only);
jaroslav@1378: * using that should be quicker than the otherwise obvious code:
jaroslav@1378: *
jaroslav@1378: * return "[" + getTypeDescriptor(type.getComponentType());
jaroslav@1378: */
jaroslav@1378: return type.getName().replace('.', '/');
jaroslav@1378: } else {
jaroslav@1378: return "L" + dotToSlash(type.getName()) + ";";
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Returns a human-readable string representing the signature of a
jaroslav@1378: * method with the given name and parameter types.
jaroslav@1378: */
jaroslav@1378: private static String getFriendlyMethodSignature(String name,
jaroslav@1378: Class[] parameterTypes) {
jaroslav@1378: StringBuilder sig = new StringBuilder(name);
jaroslav@1378: sig.append('(');
jaroslav@1378: for (int i = 0; i < parameterTypes.length; i++) {
jaroslav@1378: if (i > 0) {
jaroslav@1378: sig.append(',');
jaroslav@1378: }
jaroslav@1378: Class parameterType = parameterTypes[i];
jaroslav@1378: int dimensions = 0;
jaroslav@1378: while (parameterType.isArray()) {
jaroslav@1378: parameterType = parameterType.getComponentType();
jaroslav@1378: dimensions++;
jaroslav@1378: }
jaroslav@1378: sig.append(parameterType.getName());
jaroslav@1378: while (dimensions-- > 0) {
jaroslav@1378: sig.append("[]");
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: sig.append(')');
jaroslav@1378: return sig.toString();
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Add to the given list all of the types in the "from" array that are
jaroslav@1378: * not already contained in the list and are assignable to at least one
jaroslav@1378: * of the types in the "with" array.
jaroslav@1378: *
jaroslav@1378: * This method is useful for computing the greatest common set of
jaroslav@1378: * declared exceptions from duplicate methods inherited from different
jaroslav@1378: * interfaces.
jaroslav@1378: */
jaroslav@1378: private static void collectCompatibleTypes(Class[] from,
jaroslav@1378: Class[] with,
jaroslav@1378: List> list) {
jaroslav@1378: for (int i = 0; i < from.length; i++) {
jaroslav@1378: if (!list.contains(from[i])) {
jaroslav@1378: for (int j = 0; j < with.length; j++) {
jaroslav@1378: if (with[j].isAssignableFrom(from[i])) {
jaroslav@1378: list.add(from[i]);
jaroslav@1378: break;
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * A PrimitiveTypeInfo object contains assorted information about a
jaroslav@1378: * primitive type in its public fields. The struct for a particular
jaroslav@1378: * primitive type can be obtained using the static "get" method.
jaroslav@1378: */
jaroslav@1378: private static class PrimitiveTypeInfo {
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * "base type" used in various descriptors (see JVMS section 4.3.2)
jaroslav@1378: */
jaroslav@1378: public String baseTypeString;
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * name of corresponding wrapper class
jaroslav@1378: */
jaroslav@1378: public String wrapperClassName;
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * method descriptor for wrapper class "valueOf" factory method
jaroslav@1378: */
jaroslav@1378: public String wrapperValueOfDesc;
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * name of wrapper class method for retrieving primitive value
jaroslav@1378: */
jaroslav@1378: public String unwrapMethodName;
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * descriptor of same method
jaroslav@1378: */
jaroslav@1378: public String unwrapMethodDesc;
jaroslav@1378:
jaroslav@1378: private static Map table
jaroslav@1378: = new HashMap();
jaroslav@1378:
jaroslav@1378: static {
jaroslav@1378: add(byte.class, Byte.class);
jaroslav@1378: add(char.class, Character.class);
jaroslav@1378: add(double.class, Double.class);
jaroslav@1378: add(float.class, Float.class);
jaroslav@1378: add(int.class, Integer.class);
jaroslav@1378: add(long.class, Long.class);
jaroslav@1378: add(short.class, Short.class);
jaroslav@1378: add(boolean.class, Boolean.class);
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: private static void add(Class primitiveClass, Class wrapperClass) {
jaroslav@1378: table.put(primitiveClass,
jaroslav@1378: new PrimitiveTypeInfo(primitiveClass, wrapperClass));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: private PrimitiveTypeInfo(Class primitiveClass, Class wrapperClass) {
jaroslav@1378: assert primitiveClass.isPrimitive();
jaroslav@1378:
jaroslav@1378: baseTypeString
jaroslav@1378: = Array.newInstance(primitiveClass, 0)
jaroslav@1378: .getClass().getName().substring(1);
jaroslav@1378: wrapperClassName = dotToSlash(wrapperClass.getName());
jaroslav@1378: wrapperValueOfDesc
jaroslav@1378: = "(" + baseTypeString + ")L" + wrapperClassName + ";";
jaroslav@1378: unwrapMethodName = primitiveClass.getName() + "Value";
jaroslav@1378: unwrapMethodDesc = "()" + baseTypeString;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: public static PrimitiveTypeInfo get(Class cl) {
jaroslav@1378: return table.get(cl);
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * A ConstantPool object represents the constant pool of a class file
jaroslav@1378: * being generated. This representation of a constant pool is designed
jaroslav@1378: * specifically for use by ProxyGenerator; in particular, it assumes
jaroslav@1378: * that constant pool entries will not need to be resorted (for example,
jaroslav@1378: * by their type, as the Java compiler does), so that the final index
jaroslav@1378: * value can be assigned and used when an entry is first created.
jaroslav@1378: *
jaroslav@1378: * Note that new entries cannot be created after the constant pool has
jaroslav@1378: * been written to a class file. To prevent such logic errors, a
jaroslav@1378: * ConstantPool instance can be marked "read only", so that further
jaroslav@1378: * attempts to add new entries will fail with a runtime exception.
jaroslav@1378: *
jaroslav@1378: * See JVMS section 4.4 for more information about the constant pool of
jaroslav@1378: * a class file.
jaroslav@1378: */
jaroslav@1378: private static class ConstantPool {
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * list of constant pool entries, in constant pool index order.
jaroslav@1378: *
jaroslav@1378: * This list is used when writing the constant pool to a stream and
jaroslav@1378: * for assigning the next index value. Note that element 0 of this
jaroslav@1378: * list corresponds to constant pool index 1.
jaroslav@1378: */
jaroslav@1378: private List pool = new ArrayList(32);
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * maps constant pool data of all types to constant pool indexes.
jaroslav@1378: *
jaroslav@1378: * This map is used to look up the index of an existing entry for
jaroslav@1378: * values of all types.
jaroslav@1378: */
jaroslav@1378: private Map map = new HashMap(16);
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * true if no new constant pool entries may be added
jaroslav@1378: */
jaroslav@1378: private boolean readOnly = false;
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for a CONSTANT_Utf8 entry.
jaroslav@1378: */
jaroslav@1378: public short getUtf8(String s) {
jaroslav@1378: if (s == null) {
jaroslav@1378: throw new NullPointerException();
jaroslav@1378: }
jaroslav@1378: return getValue(s);
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for a CONSTANT_Integer entry.
jaroslav@1378: */
jaroslav@1378: public short getInteger(int i) {
jaroslav@1378: return getValue(new Integer(i));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for a CONSTANT_Float entry.
jaroslav@1378: */
jaroslav@1378: public short getFloat(float f) {
jaroslav@1378: return getValue(new Float(f));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for a CONSTANT_Class entry.
jaroslav@1378: */
jaroslav@1378: public short getClass(String name) {
jaroslav@1378: short utf8Index = getUtf8(name);
jaroslav@1378: return getIndirect(new IndirectEntry(
jaroslav@1378: CONSTANT_CLASS, utf8Index));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for a CONSTANT_String entry.
jaroslav@1378: */
jaroslav@1378: public short getString(String s) {
jaroslav@1378: short utf8Index = getUtf8(s);
jaroslav@1378: return getIndirect(new IndirectEntry(
jaroslav@1378: CONSTANT_STRING, utf8Index));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for a CONSTANT_FieldRef entry.
jaroslav@1378: */
jaroslav@1378: public short getFieldRef(String className,
jaroslav@1378: String name, String descriptor) {
jaroslav@1378: short classIndex = getClass(className);
jaroslav@1378: short nameAndTypeIndex = getNameAndType(name, descriptor);
jaroslav@1378: return getIndirect(new IndirectEntry(
jaroslav@1378: CONSTANT_FIELD, classIndex, nameAndTypeIndex));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for a CONSTANT_MethodRef entry.
jaroslav@1378: */
jaroslav@1378: public short getMethodRef(String className,
jaroslav@1378: String name, String descriptor) {
jaroslav@1378: short classIndex = getClass(className);
jaroslav@1378: short nameAndTypeIndex = getNameAndType(name, descriptor);
jaroslav@1378: return getIndirect(new IndirectEntry(
jaroslav@1378: CONSTANT_METHOD, classIndex, nameAndTypeIndex));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for a CONSTANT_InterfaceMethodRef entry.
jaroslav@1378: */
jaroslav@1378: public short getInterfaceMethodRef(String className, String name,
jaroslav@1378: String descriptor) {
jaroslav@1378: short classIndex = getClass(className);
jaroslav@1378: short nameAndTypeIndex = getNameAndType(name, descriptor);
jaroslav@1378: return getIndirect(new IndirectEntry(
jaroslav@1378: CONSTANT_INTERFACEMETHOD, classIndex, nameAndTypeIndex));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for a CONSTANT_NameAndType entry.
jaroslav@1378: */
jaroslav@1378: public short getNameAndType(String name, String descriptor) {
jaroslav@1378: short nameIndex = getUtf8(name);
jaroslav@1378: short descriptorIndex = getUtf8(descriptor);
jaroslav@1378: return getIndirect(new IndirectEntry(
jaroslav@1378: CONSTANT_NAMEANDTYPE, nameIndex, descriptorIndex));
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Set this ConstantPool instance to be "read only".
jaroslav@1378: *
jaroslav@1378: * After this method has been called, further requests to get an
jaroslav@1378: * index for a non-existent entry will cause an InternalError to be
jaroslav@1378: * thrown instead of creating of the entry.
jaroslav@1378: */
jaroslav@1378: public void setReadOnly() {
jaroslav@1378: readOnly = true;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Write this constant pool to a stream as part of the class file
jaroslav@1378: * format.
jaroslav@1378: *
jaroslav@1378: * This consists of writing the "constant_pool_count" and
jaroslav@1378: * "constant_pool[]" items of the "ClassFile" structure, as
jaroslav@1378: * described in JVMS section 4.1.
jaroslav@1378: */
jaroslav@1378: public void write(OutputStream out) throws IOException {
jaroslav@1378: DataOutputStream dataOut = new DataOutputStream(out);
jaroslav@1378:
jaroslav@1378: // constant_pool_count: number of entries plus one
jaroslav@1378: dataOut.writeShort(pool.size() + 1);
jaroslav@1378:
jaroslav@1378: for (Entry e : pool) {
jaroslav@1378: e.write(dataOut);
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Add a new constant pool entry and return its index.
jaroslav@1378: */
jaroslav@1378: private short addEntry(Entry entry) {
jaroslav@1378: pool.add(entry);
jaroslav@1378: /*
jaroslav@1378: * Note that this way of determining the index of the
jaroslav@1378: * added entry is wrong if this pool supports
jaroslav@1378: * CONSTANT_Long or CONSTANT_Double entries.
jaroslav@1378: */
jaroslav@1378: if (pool.size() >= 65535) {
jaroslav@1378: throw new IllegalArgumentException(
jaroslav@1378: "constant pool size limit exceeded");
jaroslav@1378: }
jaroslav@1378: return (short) pool.size();
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for an entry of a type that contains a
jaroslav@1378: * direct value. The type of the given object determines the type of
jaroslav@1378: * the desired entry as follows:
jaroslav@1378: *
jaroslav@1378: * java.lang.String CONSTANT_Utf8 java.lang.Integer CONSTANT_Integer
jaroslav@1378: * java.lang.Float CONSTANT_Float java.lang.Long CONSTANT_Long
jaroslav@1378: * java.lang.Double CONSTANT_DOUBLE
jaroslav@1378: */
jaroslav@1378: private short getValue(Object key) {
jaroslav@1378: Short index = map.get(key);
jaroslav@1378: if (index != null) {
jaroslav@1378: return index.shortValue();
jaroslav@1378: } else {
jaroslav@1378: if (readOnly) {
jaroslav@1378: throw new InternalError(
jaroslav@1378: "late constant pool addition: " + key);
jaroslav@1378: }
jaroslav@1378: short i = addEntry(new ValueEntry(key));
jaroslav@1378: map.put(key, new Short(i));
jaroslav@1378: return i;
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Get or assign the index for an entry of a type that contains
jaroslav@1378: * references to other constant pool entries.
jaroslav@1378: */
jaroslav@1378: private short getIndirect(IndirectEntry e) {
jaroslav@1378: Short index = map.get(e);
jaroslav@1378: if (index != null) {
jaroslav@1378: return index.shortValue();
jaroslav@1378: } else {
jaroslav@1378: if (readOnly) {
jaroslav@1378: throw new InternalError("late constant pool addition");
jaroslav@1378: }
jaroslav@1378: short i = addEntry(e);
jaroslav@1378: map.put(e, new Short(i));
jaroslav@1378: return i;
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Entry is the abstact superclass of all constant pool entry types
jaroslav@1378: * that can be stored in the "pool" list; its purpose is to define a
jaroslav@1378: * common method for writing constant pool entries to a class file.
jaroslav@1378: */
jaroslav@1378: private static abstract class Entry {
jaroslav@1378:
jaroslav@1378: public abstract void write(DataOutputStream out)
jaroslav@1378: throws IOException;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * ValueEntry represents a constant pool entry of a type that
jaroslav@1378: * contains a direct value (see the comments for the "getValue"
jaroslav@1378: * method for a list of such types).
jaroslav@1378: *
jaroslav@1378: * ValueEntry objects are not used as keys for their entries in the
jaroslav@1378: * Map "map", so no useful hashCode or equals methods are defined.
jaroslav@1378: */
jaroslav@1378: private static class ValueEntry extends Entry {
jaroslav@1378:
jaroslav@1378: private Object value;
jaroslav@1378:
jaroslav@1378: public ValueEntry(Object value) {
jaroslav@1378: this.value = value;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: public void write(DataOutputStream out) throws IOException {
jaroslav@1378: if (value instanceof String) {
jaroslav@1378: out.writeByte(CONSTANT_UTF8);
jaroslav@1378: out.writeUTF((String) value);
jaroslav@1378: } else if (value instanceof Integer) {
jaroslav@1378: out.writeByte(CONSTANT_INTEGER);
jaroslav@1378: out.writeInt(((Integer) value).intValue());
jaroslav@1378: } else if (value instanceof Float) {
jaroslav@1378: out.writeByte(CONSTANT_FLOAT);
jaroslav@1378: out.writeFloat(((Float) value).floatValue());
jaroslav@1378: } else if (value instanceof Long) {
jaroslav@1378: out.writeByte(CONSTANT_LONG);
jaroslav@1378: out.writeLong(((Long) value).longValue());
jaroslav@1378: } else if (value instanceof Double) {
jaroslav@1378: out.writeDouble(CONSTANT_DOUBLE);
jaroslav@1378: out.writeDouble(((Double) value).doubleValue());
jaroslav@1378: } else {
jaroslav@1378: throw new InternalError("bogus value entry: " + value);
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * IndirectEntry represents a constant pool entry of a type that
jaroslav@1378: * references other constant pool entries, i.e., the following
jaroslav@1378: * types:
jaroslav@1378: *
jaroslav@1378: * CONSTANT_Class, CONSTANT_String, CONSTANT_Fieldref,
jaroslav@1378: * CONSTANT_Methodref, CONSTANT_InterfaceMethodref, and
jaroslav@1378: * CONSTANT_NameAndType.
jaroslav@1378: *
jaroslav@1378: * Each of these entry types contains either one or two indexes of
jaroslav@1378: * other constant pool entries.
jaroslav@1378: *
jaroslav@1378: * IndirectEntry objects are used as the keys for their entries in
jaroslav@1378: * the Map "map", so the hashCode and equals methods are overridden
jaroslav@1378: * to allow matching.
jaroslav@1378: */
jaroslav@1378: private static class IndirectEntry extends Entry {
jaroslav@1378:
jaroslav@1378: private int tag;
jaroslav@1378: private short index0;
jaroslav@1378: private short index1;
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Construct an IndirectEntry for a constant pool entry type
jaroslav@1378: * that contains one index of another entry.
jaroslav@1378: */
jaroslav@1378: public IndirectEntry(int tag, short index) {
jaroslav@1378: this.tag = tag;
jaroslav@1378: this.index0 = index;
jaroslav@1378: this.index1 = 0;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: /**
jaroslav@1378: * Construct an IndirectEntry for a constant pool entry type
jaroslav@1378: * that contains two indexes for other entries.
jaroslav@1378: */
jaroslav@1378: public IndirectEntry(int tag, short index0, short index1) {
jaroslav@1378: this.tag = tag;
jaroslav@1378: this.index0 = index0;
jaroslav@1378: this.index1 = index1;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: public void write(DataOutputStream out) throws IOException {
jaroslav@1378: out.writeByte(tag);
jaroslav@1378: out.writeShort(index0);
jaroslav@1378: /*
jaroslav@1378: * If this entry type contains two indexes, write
jaroslav@1378: * out the second, too.
jaroslav@1378: */
jaroslav@1378: if (tag == CONSTANT_FIELD
jaroslav@1378: || tag == CONSTANT_METHOD
jaroslav@1378: || tag == CONSTANT_INTERFACEMETHOD
jaroslav@1378: || tag == CONSTANT_NAMEANDTYPE) {
jaroslav@1378: out.writeShort(index1);
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: public int hashCode() {
jaroslav@1378: return tag + index0 + index1;
jaroslav@1378: }
jaroslav@1378:
jaroslav@1378: public boolean equals(Object obj) {
jaroslav@1378: if (obj instanceof IndirectEntry) {
jaroslav@1378: IndirectEntry other = (IndirectEntry) obj;
jaroslav@1378: if (tag == other.tag
jaroslav@1378: && index0 == other.index0 && index1 == other.index1) {
jaroslav@1378: return true;
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: return false;
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378: }
jaroslav@1378:
jaroslav@601: }