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Java > Open Source Codes > com > google > inject > InterceptorStackCallback


1 /**
2  * Copyright (C) 2006 Google Inc.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17 package com.google.inject;
18
19 import java.lang.reflect.AccessibleObject JavaDoc;
20 import java.lang.reflect.Method JavaDoc;
21 import java.util.List JavaDoc;
22 import net.sf.cglib.proxy.MethodProxy;
23 import org.aopalliance.intercept.MethodInterceptor;
24 import org.aopalliance.intercept.MethodInvocation;
25
26 /**
27  * Intercepts a method with a stack of interceptors.
28  *
29  * @author crazybob@google.com (Bob Lee)
30  */
31 class InterceptorStackCallback implements net.sf.cglib.proxy.MethodInterceptor {
32
33   final MethodInterceptor[] interceptors;
34   final Method JavaDoc method;
35
36   public InterceptorStackCallback(Method JavaDoc method,
37       List JavaDoc<MethodInterceptor> interceptors) {
38     this.method = method;
39     this.interceptors
40         = interceptors.toArray(new MethodInterceptor[interceptors.size()]);
41   }
42
43   public Object JavaDoc intercept(Object JavaDoc proxy, Method JavaDoc method, Object JavaDoc[] arguments,
44       MethodProxy methodProxy) throws Throwable JavaDoc {
45     return new InterceptedMethodInvocation(proxy, methodProxy, arguments)
46         .proceed();
47   }
48
49   class InterceptedMethodInvocation implements MethodInvocation {
50
51     final Object JavaDoc proxy;
52     final Object JavaDoc[] arguments;
53     final MethodProxy methodProxy;
54     int index = -1;
55
56     public InterceptedMethodInvocation(Object JavaDoc proxy, MethodProxy methodProxy,
57         Object JavaDoc[] arguments) {
58       this.proxy = proxy;
59       this.methodProxy = methodProxy;
60       this.arguments = arguments;
61     }
62
63     public Object JavaDoc proceed() throws Throwable JavaDoc {
64       try {
65         index++;
66         return index == interceptors.length
67             ? methodProxy.invokeSuper(proxy, arguments)
68             : interceptors[index].invoke(this);
69       }
70       finally {
71         index--;
72       }
73     }
74
75     public Method JavaDoc getMethod() {
76       return method;
77     }
78
79     public Object JavaDoc[] getArguments() {
80       return arguments;
81     }
82
83     public Object JavaDoc getThis() {
84       return proxy;
85     }
86
87     public AccessibleObject JavaDoc getStaticPart() {
88       return getMethod();
89     }
90   }
91 }
92
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