| /* |
| * Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package java.rmi.server; |
| |
| import java.io.InvalidObjectException; |
| import java.lang.reflect.InvocationHandler; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Proxy; |
| import java.rmi.Remote; |
| import java.rmi.UnexpectedException; |
| import java.rmi.activation.Activatable; |
| import java.util.Map; |
| import java.util.WeakHashMap; |
| import sun.rmi.server.Util; |
| import sun.rmi.server.WeakClassHashMap; |
| |
| /** |
| * An implementation of the <code>InvocationHandler</code> interface for |
| * use with Java Remote Method Invocation (Java RMI). This invocation |
| * handler can be used in conjunction with a dynamic proxy instance as a |
| * replacement for a pregenerated stub class. |
| * |
| * <p>Applications are not expected to use this class directly. A remote |
| * object exported to use a dynamic proxy with {@link UnicastRemoteObject} |
| * or {@link Activatable} has an instance of this class as that proxy's |
| * invocation handler. |
| * |
| * @author Ann Wollrath |
| * @since 1.5 |
| **/ |
| public class RemoteObjectInvocationHandler |
| extends RemoteObject |
| implements InvocationHandler |
| { |
| private static final long serialVersionUID = 2L; |
| |
| /** |
| * A weak hash map, mapping classes to weak hash maps that map |
| * method objects to method hashes. |
| **/ |
| private static final MethodToHash_Maps methodToHash_Maps = |
| new MethodToHash_Maps(); |
| |
| /** |
| * Creates a new <code>RemoteObjectInvocationHandler</code> constructed |
| * with the specified <code>RemoteRef</code>. |
| * |
| * @param ref the remote ref |
| * |
| * @throws NullPointerException if <code>ref</code> is <code>null</code> |
| **/ |
| public RemoteObjectInvocationHandler(RemoteRef ref) { |
| super(ref); |
| if (ref == null) { |
| throw new NullPointerException(); |
| } |
| } |
| |
| /** |
| * Processes a method invocation made on the encapsulating |
| * proxy instance, <code>proxy</code>, and returns the result. |
| * |
| * <p><code>RemoteObjectInvocationHandler</code> implements this method |
| * as follows: |
| * |
| * <p>If <code>method</code> is one of the following methods, it |
| * is processed as described below: |
| * |
| * <ul> |
| * |
| * <li>{@link Object#hashCode Object.hashCode}: Returns the hash |
| * code value for the proxy. |
| * |
| * <li>{@link Object#equals Object.equals}: Returns <code>true</code> |
| * if the argument (<code>args[0]</code>) is an instance of a dynamic |
| * proxy class and this invocation handler is equal to the invocation |
| * handler of that argument, and returns <code>false</code> otherwise. |
| * |
| * <li>{@link Object#toString Object.toString}: Returns a string |
| * representation of the proxy. |
| * </ul> |
| * |
| * <p>Otherwise, a remote call is made as follows: |
| * |
| * <ul> |
| * <li>If <code>proxy</code> is not an instance of the interface |
| * {@link Remote}, then an {@link IllegalArgumentException} is thrown. |
| * |
| * <li>Otherwise, the {@link RemoteRef#invoke invoke} method is invoked |
| * on this invocation handler's <code>RemoteRef</code>, passing |
| * <code>proxy</code>, <code>method</code>, <code>args</code>, and the |
| * method hash (defined in section 8.3 of the "Java Remote Method |
| * Invocation (RMI) Specification") for <code>method</code>, and the |
| * result is returned. |
| * |
| * <li>If an exception is thrown by <code>RemoteRef.invoke</code> and |
| * that exception is a checked exception that is not assignable to any |
| * exception in the <code>throws</code> clause of the method |
| * implemented by the <code>proxy</code>'s class, then that exception |
| * is wrapped in an {@link UnexpectedException} and the wrapped |
| * exception is thrown. Otherwise, the exception thrown by |
| * <code>invoke</code> is thrown by this method. |
| * </ul> |
| * |
| * <p>The semantics of this method are unspecified if the |
| * arguments could not have been produced by an instance of some |
| * valid dynamic proxy class containing this invocation handler. |
| * |
| * @param proxy the proxy instance that the method was invoked on |
| * @param method the <code>Method</code> instance corresponding to the |
| * interface method invoked on the proxy instance |
| * @param args an array of objects containing the values of the |
| * arguments passed in the method invocation on the proxy instance, or |
| * <code>null</code> if the method takes no arguments |
| * @return the value to return from the method invocation on the proxy |
| * instance |
| * @throws Throwable the exception to throw from the method invocation |
| * on the proxy instance |
| **/ |
| public Object invoke(Object proxy, Method method, Object[] args) |
| throws Throwable |
| { |
| if (method.getDeclaringClass() == Object.class) { |
| return invokeObjectMethod(proxy, method, args); |
| } else { |
| return invokeRemoteMethod(proxy, method, args); |
| } |
| } |
| |
| /** |
| * Handles java.lang.Object methods. |
| **/ |
| private Object invokeObjectMethod(Object proxy, |
| Method method, |
| Object[] args) |
| { |
| String name = method.getName(); |
| |
| if (name.equals("hashCode")) { |
| return hashCode(); |
| |
| } else if (name.equals("equals")) { |
| Object obj = args[0]; |
| return |
| proxy == obj || |
| (obj != null && |
| Proxy.isProxyClass(obj.getClass()) && |
| equals(Proxy.getInvocationHandler(obj))); |
| |
| } else if (name.equals("toString")) { |
| return proxyToString(proxy); |
| |
| } else { |
| throw new IllegalArgumentException( |
| "unexpected Object method: " + method); |
| } |
| } |
| |
| /** |
| * Handles remote methods. |
| **/ |
| private Object invokeRemoteMethod(Object proxy, |
| Method method, |
| Object[] args) |
| throws Exception |
| { |
| try { |
| if (!(proxy instanceof Remote)) { |
| throw new IllegalArgumentException( |
| "proxy not Remote instance"); |
| } |
| return ref.invoke((Remote) proxy, method, args, |
| getMethodHash(method)); |
| } catch (Exception e) { |
| if (!(e instanceof RuntimeException)) { |
| Class<?> cl = proxy.getClass(); |
| try { |
| method = cl.getMethod(method.getName(), |
| method.getParameterTypes()); |
| } catch (NoSuchMethodException nsme) { |
| throw (IllegalArgumentException) |
| new IllegalArgumentException().initCause(nsme); |
| } |
| Class<?> thrownType = e.getClass(); |
| for (Class<?> declaredType : method.getExceptionTypes()) { |
| if (declaredType.isAssignableFrom(thrownType)) { |
| throw e; |
| } |
| } |
| e = new UnexpectedException("unexpected exception", e); |
| } |
| throw e; |
| } |
| } |
| |
| /** |
| * Returns a string representation for a proxy that uses this invocation |
| * handler. |
| **/ |
| private String proxyToString(Object proxy) { |
| Class<?>[] interfaces = proxy.getClass().getInterfaces(); |
| if (interfaces.length == 0) { |
| return "Proxy[" + this + "]"; |
| } |
| String iface = interfaces[0].getName(); |
| if (iface.equals("java.rmi.Remote") && interfaces.length > 1) { |
| iface = interfaces[1].getName(); |
| } |
| int dot = iface.lastIndexOf('.'); |
| if (dot >= 0) { |
| iface = iface.substring(dot + 1); |
| } |
| return "Proxy[" + iface + "," + this + "]"; |
| } |
| |
| /** |
| * @throws InvalidObjectException unconditionally |
| **/ |
| private void readObjectNoData() throws InvalidObjectException { |
| throw new InvalidObjectException("no data in stream; class: " + |
| this.getClass().getName()); |
| } |
| |
| /** |
| * Returns the method hash for the specified method. Subsequent calls |
| * to "getMethodHash" passing the same method argument should be faster |
| * since this method caches internally the result of the method to |
| * method hash mapping. The method hash is calculated using the |
| * "computeMethodHash" method. |
| * |
| * @param method the remote method |
| * @return the method hash for the specified method |
| */ |
| private static long getMethodHash(Method method) { |
| return methodToHash_Maps.get(method.getDeclaringClass()).get(method); |
| } |
| |
| /** |
| * A weak hash map, mapping classes to weak hash maps that map |
| * method objects to method hashes. |
| **/ |
| private static class MethodToHash_Maps |
| extends WeakClassHashMap<Map<Method,Long>> |
| { |
| MethodToHash_Maps() {} |
| |
| protected Map<Method,Long> computeValue(Class<?> remoteClass) { |
| return new WeakHashMap<Method,Long>() { |
| public synchronized Long get(Object key) { |
| Long hash = super.get(key); |
| if (hash == null) { |
| Method method = (Method) key; |
| hash = Util.computeMethodHash(method); |
| put(method, hash); |
| } |
| return hash; |
| } |
| }; |
| } |
| } |
| } |