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Java > Open Source Codes > org > apache > commons > httpclient > DefaultHttpMethodRetryHandler


1 /*
2  * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/DefaultHttpMethodRetryHandler.java,v 1.3 2004/12/20 11:47:46 olegk Exp $
3  * $Revision: 480424 $
4  * $Date: 2006-11-29 05:56:49 +0000 (Wed, 29 Nov 2006) $
5  *
6  * ====================================================================
7  *
8  * Licensed to the Apache Software Foundation (ASF) under one or more
9  * contributor license agreements. See the NOTICE file distributed with
10  * this work for additional information regarding copyright ownership.
11  * The ASF licenses this file to You under the Apache License, Version 2.0
12  * (the "License"); you may not use this file except in compliance with
13  * the License. You may obtain a copy of the License at
14  *
15  * http://www.apache.org/licenses/LICENSE-2.0
16  *
17  * Unless required by applicable law or agreed to in writing, software
18  * distributed under the License is distributed on an "AS IS" BASIS,
19  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20  * See the License for the specific language governing permissions and
21  * limitations under the License.
22  * ====================================================================
23  *
24  * This software consists of voluntary contributions made by many
25  * individuals on behalf of the Apache Software Foundation. For more
26  * information on the Apache Software Foundation, please see
27  * <http://www.apache.org/>.
28  *
29  */
30
31 package org.apache.commons.httpclient;
32
33 import java.io.IOException JavaDoc;
34 import java.io.InterruptedIOException JavaDoc;
35 import java.net.NoRouteToHostException JavaDoc;
36 import java.net.UnknownHostException JavaDoc;
37
38 /**
39  * The default {@link HttpMethodRetryHandler} used by {@link HttpMethod}s.
40  *
41  * @author Michael Becke
42  * @author <a HREF="mailto:oleg -at- ural.ru">Oleg Kalnichevski</a>
43  */
44 public class DefaultHttpMethodRetryHandler implements HttpMethodRetryHandler {
45
46
47     private static Class JavaDoc SSL_HANDSHAKE_EXCEPTION = null;
48     
49     static {
50         try {
51             SSL_HANDSHAKE_EXCEPTION = Class.forName("javax.net.ssl.SSLHandshakeException");
52         } catch (ClassNotFoundException JavaDoc ignore) {
53         }
54     }
55     /** the number of times a method will be retried */
56     private int retryCount;
57     
58     /** Whether or not methods that have successfully sent their request will be retried */
59     private boolean requestSentRetryEnabled;
60     
61     /**
62      * Creates a new DefaultHttpMethodRetryHandler.
63      * @param retryCount the number of times a method will be retried
64      * @param requestSentRetryEnabled if true, methods that have successfully sent their request will be retried
65      */
66     public DefaultHttpMethodRetryHandler(int retryCount, boolean requestSentRetryEnabled) {
67         super();
68         this.retryCount = retryCount;
69         this.requestSentRetryEnabled = requestSentRetryEnabled;
70     }
71     
72     /**
73      * Creates a new DefaultHttpMethodRetryHandler that retries up to 3 times
74      * but does not retry methods that have successfully sent their requests.
75      */
76     public DefaultHttpMethodRetryHandler() {
77         this(3, false);
78     }
79     /**
80      * Used <code>retryCount</code> and <code>requestSentRetryEnabled</code> to determine
81      * if the given method should be retried.
82      *
83      * @see HttpMethodRetryHandler#retryMethod(HttpMethod, IOException, int)
84      */
85     public boolean retryMethod(
86         final HttpMethod method,
87         final IOException JavaDoc exception,
88         int executionCount) {
89         if (method == null) {
90             throw new IllegalArgumentException JavaDoc("HTTP method may not be null");
91         }
92         if (exception == null) {
93             throw new IllegalArgumentException JavaDoc("Exception parameter may not be null");
94         }
95         // HttpMethod interface is the WORST thing ever done to HttpClient
96 if (method instanceof HttpMethodBase) {
97             if (((HttpMethodBase)method).isAborted()) {
98                 return false;
99             }
100         }
101         if (executionCount > this.retryCount) {
102             // Do not retry if over max retry count
103 return false;
104         }
105         if (exception instanceof NoHttpResponseException) {
106             // Retry if the server dropped connection on us
107 return true;
108         }
109         if (exception instanceof InterruptedIOException JavaDoc) {
110             // Timeout
111 return false;
112         }
113         if (exception instanceof UnknownHostException JavaDoc) {
114             // Unknown host
115 return false;
116         }
117         if (exception instanceof NoRouteToHostException JavaDoc) {
118             // Host unreachable
119 return false;
120         }
121         if (SSL_HANDSHAKE_EXCEPTION != null && SSL_HANDSHAKE_EXCEPTION.isInstance(exception)) {
122             // SSL handshake exception
123 return false;
124         }
125         if (!method.isRequestSent() || this.requestSentRetryEnabled) {
126             // Retry if the request has not been sent fully or
127 // if it's OK to retry methods that have been sent
128 return true;
129         }
130         // otherwise do not retry
131 return false;
132     }
133     
134     /**
135      * @return <code>true</code> if this handler will retry methods that have
136      * successfully sent their request, <code>false</code> otherwise
137      */
138     public boolean isRequestSentRetryEnabled() {
139         return requestSentRetryEnabled;
140     }
141
142     /**
143      * @return the maximum number of times a method will be retried
144      */
145     public int getRetryCount() {
146         return retryCount;
147     }
148 }
149
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