1/*
2 * Javassist, a Java-bytecode translator toolkit.
3 * Copyright (C) 1999-2007 Shigeru Chiba. All Rights Reserved.
4 *
5 * The contents of this file are subject to the Mozilla Public License Version
6 * 1.1 (the "License"); you may not use this file except in compliance with
7 * the License.  Alternatively, the contents of this file may be used under
8 * the terms of the GNU Lesser General Public License Version 2.1 or later.
9 *
10 * Software distributed under the License is distributed on an "AS IS" basis,
11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 * for the specific language governing rights and limitations under the
13 * License.
14 */
15
16package javassist.util.proxy;
17
18import java.lang.reflect.Method;
19
20/**
21 * The interface implemented by the invocation handler of a proxy
22 * instance.
23 *
24 * @see ProxyFactory#setHandler(MethodHandler)
25 */
26public interface MethodHandler {
27    /**
28     * Is called when a method is invoked on a proxy instance associated
29     * with this handler.  This method must process that method invocation.
30     *
31     * @param self          the proxy instance.
32     * @param thisMethod    the overridden method declared in the super
33     *                      class or interface.
34     * @param proceed       the forwarder method for invoking the overridden
35     *                      method.  It is null if the overridden mehtod is
36     *                      abstract or declared in the interface.
37     * @param args          an array of objects containing the values of
38     *                      the arguments passed in the method invocation
39     *                      on the proxy instance.  If a parameter type is
40     *                      a primitive type, the type of the array element
41     *                      is a wrapper class.
42     * @return              the resulting value of the method invocation.
43     *
44     * @throws Throwable    if the method invocation fails.
45     */
46    Object invoke(Object self, Method thisMethod, Method proceed,
47                  Object[] args) throws Throwable;
48}
49