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Java > Open Source Codes > org > apache > commons > httpclient > server > StreamProxy


1 /*
2  * $Header: /home/cvs/jakarta-commons/httpclient/src/test/org/apache/commons/httpclient/server/StreamProxy.java,v 1.1.2.2 2004/02/22 18:21:18 olegk Exp $
3  * $Revision: 1.1.2.2 $
4  * $Date: 2004/02/22 18:21:18 $
5  *
6  * ====================================================================
7  *
8  * Copyright 1999-2004 The Apache Software Foundation
9  *
10  * Licensed under the Apache License, Version 2.0 (the "License");
11  * you may not use this file except in compliance with the License.
12  * You may obtain a copy of the License at
13  *
14  * http://www.apache.org/licenses/LICENSE-2.0
15  *
16  * Unless required by applicable law or agreed to in writing, software
17  * distributed under the License is distributed on an "AS IS" BASIS,
18  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19  * See the License for the specific language governing permissions and
20  * limitations under the License.
21  * ====================================================================
22  *
23  * This software consists of voluntary contributions made by many
24  * individuals on behalf of the Apache Software Foundation. For more
25  * information on the Apache Software Foundation, please see
26  * <http://www.apache.org/>.
27  *
28  * [Additional notices, if required by prior licensing conditions]
29  *
30  */
31
32 package org.apache.commons.httpclient.server;
33
34 import java.io.IOException JavaDoc;
35 import java.io.InputStream JavaDoc;
36 import java.io.OutputStream JavaDoc;
37
38 /**
39  * Pipes all data of an input stream through to an output stream asynchronously.
40  * Instances of this class are thread safe.
41  *
42  * @author Ortwin Glueck
43  */
44 class StreamProxy {
45     private InputStream JavaDoc in;
46     private OutputStream JavaDoc out;
47     private Pump pump = new Pump();
48     private Thread JavaDoc pumpThread = new Thread JavaDoc(pump, "Stream copier");
49     private int state = 0;
50   
51     public StreamProxy(InputStream JavaDoc in, OutputStream JavaDoc out) {
52         this.in = in;
53         this.out = out;
54     }
55     
56     public synchronized void start() {
57         if (state != 0) throw new IllegalStateException JavaDoc("Can not start again.");
58         state = 1;
59         pumpThread.start();
60     }
61     
62     /**
63      * Returns immediately. The object must not be used again.
64      */
65     public void abort() {
66         if (state != 1) return;
67         state = 2;
68         pumpThread.interrupt();
69         dispose();
70     }
71     
72     /**
73      * Blocks until all data has been copied. Basically calls the
74      * join method on the pump thread.
75      * @throws InterruptedException
76      */
77     public void block() throws InterruptedException JavaDoc {
78         if (state != 1) throw new IllegalStateException JavaDoc("Can not block before started");
79         pumpThread.join();
80     }
81     
82     private void dispose() {
83         pumpThread = null;
84         pump = null;
85         in = null;
86         out = null;
87     }
88
89     private class Pump implements Runnable JavaDoc {
90
91         public void run() {
92             byte[] buffer = new byte[10000];
93             try {
94                 while (!Thread.interrupted()) {
95                     int len;
96                     while ((len = in.read(buffer)) != -1) {
97                         out.write(buffer, 0, len);
98                         out.flush();
99                     }
100                 }
101             } catch(IOException JavaDoc e) {
102                 /* expected if parties close connection */
103                 e.printStackTrace();
104             } finally {
105                 dispose();
106             }
107         }
108         
109     }
110 }
111
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