/hudson-core/src/main/java/hudson/util/InvocationInterceptor.java

 1/*
 2 * The MIT License
 3 * 
 4 * Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi
 5 * 
 6 * Permission is hereby granted, free of charge, to any person obtaining a copy
 7 * of this software and associated documentation files (the "Software"), to deal
 8 * in the Software without restriction, including without limitation the rights
 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 * 
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 * 
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24package hudson.util;
25
26import java.lang.reflect.Method;
27import java.lang.reflect.InvocationHandler;
28
29/**
30 * Interceptor around {@link InvocationHandler}.
31 *
32 * @author Kohsuke Kawaguchi
33 * @since 1.232
34 */
35public interface InvocationInterceptor {
36    /**
37     * This method can intercept the invocation of {@link InvocationHandler} either before or after
38     * the invocation happens.
39     *
40     * <p>
41     * The general coding pattern is:
42     *
43     * <pre>
44     * Object invoke(Object proxy, Method method, Object[] args, InvocationHandler delegate) {
45     *   ... do pre-invocation work ...
46     *   ret = delegate.invoke(proxy,method,args);
47     *   ... do post-invocation work ...
48     *   return ret;
49     * }
50     * </pre>
51     *
52     * <p>
53     * But the implementation may choose to skip calling the 'delegate' object, alter arguments,
54     * and alter the return value. 
55     */
56    public Object invoke(Object proxy, Method method, Object[] args, InvocationHandler delegate) throws Throwable;
57}