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Java > Open Source Codes > org > apache > catalina > util > CustomObjectInputStream


1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one or more
3  * contributor license agreements. See the NOTICE file distributed with
4  * this work for additional information regarding copyright ownership.
5  * The ASF licenses this file to You under the Apache License, Version 2.0
6  * (the "License"); you may not use this file except in compliance with
7  * the License. You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17
18 package org.apache.catalina.util;
19
20 import java.io.InputStream JavaDoc;
21 import java.io.IOException JavaDoc;
22 import java.io.ObjectInputStream JavaDoc;
23 import java.io.ObjectStreamClass JavaDoc;
24 import java.lang.reflect.Proxy JavaDoc;
25
26 /**
27  * Custom subclass of <code>ObjectInputStream</code> that loads from the
28  * class loader for this web application. This allows classes defined only
29  * with the web application to be found correctly.
30  *
31  * @author Craig R. McClanahan
32  * @author Bip Thelin
33  * @version $Revision: 467222 $, $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
34  */
35
36 public final class CustomObjectInputStream
37     extends ObjectInputStream JavaDoc {
38
39
40     /**
41      * The class loader we will use to resolve classes.
42      */
43     private ClassLoader JavaDoc classLoader = null;
44
45
46     /**
47      * Construct a new instance of CustomObjectInputStream
48      *
49      * @param stream The input stream we will read from
50      * @param classLoader The class loader used to instantiate objects
51      *
52      * @exception IOException if an input/output error occurs
53      */
54     public CustomObjectInputStream(InputStream JavaDoc stream,
55                                    ClassLoader JavaDoc classLoader)
56         throws IOException JavaDoc {
57
58         super(stream);
59         this.classLoader = classLoader;
60     }
61
62
63     /**
64      * Load the local class equivalent of the specified stream class
65      * description, by using the class loader assigned to this Context.
66      *
67      * @param classDesc Class description from the input stream
68      *
69      * @exception ClassNotFoundException if this class cannot be found
70      * @exception IOException if an input/output error occurs
71      */
72     public Class JavaDoc resolveClass(ObjectStreamClass JavaDoc classDesc)
73         throws ClassNotFoundException JavaDoc, IOException JavaDoc {
74         try {
75             return Class.forName(classDesc.getName(), false, classLoader);
76         } catch (ClassNotFoundException JavaDoc e) {
77             // Try also the superclass because of primitive types
78 return super.resolveClass(classDesc);
79         }
80     }
81
82
83     /**
84      * Return a proxy class that implements the interfaces named in a proxy
85      * class descriptor. Do this using the class loader assigned to this
86      * Context.
87      */
88     protected Class JavaDoc resolveProxyClass(String JavaDoc[] interfaces)
89         throws IOException JavaDoc, ClassNotFoundException JavaDoc {
90
91         Class JavaDoc[] cinterfaces = new Class JavaDoc[interfaces.length];
92         for (int i = 0; i < interfaces.length; i++)
93             cinterfaces[i] = classLoader.loadClass(interfaces[i]);
94
95         try {
96             return Proxy.getProxyClass(classLoader, cinterfaces);
97         } catch (IllegalArgumentException JavaDoc e) {
98             throw new ClassNotFoundException JavaDoc(null, e);
99         }
100     }
101
102 }
103
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