1 /* 2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/impl/client/DefaultHttpRequestRetryHandler.java $ 3 * $Revision: 652726 $ 4 * $Date: 2008-05-01 18:16:51 -0700 (Thu, 01 May 2008) $ 5 * 6 * ==================================================================== 7 * Licensed to the Apache Software Foundation (ASF) under one 8 * or more contributor license agreements. See the NOTICE file 9 * distributed with this work for additional information 10 * regarding copyright ownership. The ASF licenses this file 11 * to you under the Apache License, Version 2.0 (the 12 * "License"); you may not use this file except in compliance 13 * with 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, 18 * software distributed under the License is distributed on an 19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 20 * KIND, either express or implied. See the License for the 21 * specific language governing permissions and limitations 22 * under the License. 23 * ==================================================================== 24 * 25 * This software consists of voluntary contributions made by many 26 * individuals on behalf of the Apache Software Foundation. For more 27 * information on the Apache Software Foundation, please see 28 * <http://www.apache.org/>. 29 * 30 */ 31 32 package org.apache.http.impl.client; 33 34 import java.io.IOException; 35 import java.io.InterruptedIOException; 36 import java.net.UnknownHostException; 37 38 import javax.net.ssl.SSLHandshakeException; 39 40 import org.apache.http.NoHttpResponseException; 41 import org.apache.http.client.HttpRequestRetryHandler; 42 import org.apache.http.protocol.HttpContext; 43 import org.apache.http.protocol.ExecutionContext; 44 45 /** 46 * The default {@link HttpRequestRetryHandler} used by request executors. 47 * 48 * @author Michael Becke 49 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a> 50 */ 51 public class DefaultHttpRequestRetryHandler implements HttpRequestRetryHandler { 52 53 /** the number of times a method will be retried */ 54 private final int retryCount; 55 56 /** Whether or not methods that have successfully sent their request will be retried */ 57 private final boolean requestSentRetryEnabled; 58 59 /** 60 * Default constructor 61 */ DefaultHttpRequestRetryHandler(int retryCount, boolean requestSentRetryEnabled)62 public DefaultHttpRequestRetryHandler(int retryCount, boolean requestSentRetryEnabled) { 63 super(); 64 this.retryCount = retryCount; 65 this.requestSentRetryEnabled = requestSentRetryEnabled; 66 } 67 68 /** 69 * Default constructor 70 */ DefaultHttpRequestRetryHandler()71 public DefaultHttpRequestRetryHandler() { 72 this(3, false); 73 } 74 /** 75 * Used <code>retryCount</code> and <code>requestSentRetryEnabled</code> to determine 76 * if the given method should be retried. 77 */ retryRequest( final IOException exception, int executionCount, final HttpContext context)78 public boolean retryRequest( 79 final IOException exception, 80 int executionCount, 81 final HttpContext context) { 82 if (exception == null) { 83 throw new IllegalArgumentException("Exception parameter may not be null"); 84 } 85 if (context == null) { 86 throw new IllegalArgumentException("HTTP context may not be null"); 87 } 88 if (executionCount > this.retryCount) { 89 // Do not retry if over max retry count 90 return false; 91 } 92 if (exception instanceof NoHttpResponseException) { 93 // Retry if the server dropped connection on us 94 return true; 95 } 96 if (exception instanceof InterruptedIOException) { 97 // Timeout 98 return false; 99 } 100 if (exception instanceof UnknownHostException) { 101 // Unknown host 102 return false; 103 } 104 if (exception instanceof SSLHandshakeException) { 105 // SSL handshake exception 106 return false; 107 } 108 Boolean b = (Boolean) 109 context.getAttribute(ExecutionContext.HTTP_REQ_SENT); 110 boolean sent = (b != null && b.booleanValue()); 111 if (!sent || this.requestSentRetryEnabled) { 112 // Retry if the request has not been sent fully or 113 // if it's OK to retry methods that have been sent 114 return true; 115 } 116 // otherwise do not retry 117 return false; 118 } 119 120 /** 121 * @return <code>true</code> if this handler will retry methods that have 122 * successfully sent their request, <code>false</code> otherwise 123 */ isRequestSentRetryEnabled()124 public boolean isRequestSentRetryEnabled() { 125 return requestSentRetryEnabled; 126 } 127 128 /** 129 * @return the maximum number of times a method will be retried 130 */ getRetryCount()131 public int getRetryCount() { 132 return retryCount; 133 } 134 } 135