1 /*
2  * ====================================================================
3  * Licensed to the Apache Software Foundation (ASF) under one
4  * or more contributor license agreements.  See the NOTICE file
5  * distributed with this work for additional information
6  * regarding copyright ownership.  The ASF licenses this file
7  * to you under the Apache License, Version 2.0 (the
8  * "License"); you may not use this file except in compliance
9  * with the License.  You may obtain a copy of the License at
10  *
11  *   http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing,
14  * software distributed under the License is distributed on an
15  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16  * KIND, either express or implied.  See the License for the
17  * specific language governing permissions and limitations
18  * under the License.
19  * ====================================================================
20  *
21  * This software consists of voluntary contributions made by many
22  * individuals on behalf of the Apache Software Foundation.  For more
23  * information on the Apache Software Foundation, please see
24  * <http://www.apache.org/>.
25  *
26  */
27
28 package org.apache.http.impl.execchain;
29
30 import java.io.IOException;
31
32 import org.apache.commons.logging.Log;
33 import org.apache.commons.logging.LogFactory;
34 import org.apache.http.Header;
35 import org.apache.http.HttpException;
36 import org.apache.http.NoHttpResponseException;
37 import org.apache.http.annotation.Contract;
38 import org.apache.http.annotation.ThreadingBehavior;
39 import org.apache.http.client.HttpRequestRetryHandler;
40 import org.apache.http.client.NonRepeatableRequestException;
41 import org.apache.http.client.methods.CloseableHttpResponse;
42 import org.apache.http.client.methods.HttpExecutionAware;
43 import org.apache.http.client.methods.HttpRequestWrapper;
44 import org.apache.http.client.protocol.HttpClientContext;
45 import org.apache.http.conn.routing.HttpRoute;
46 import org.apache.http.util.Args;
47
48 /**
49  * Request executor in the request execution chain that is responsible
50  * for making a decision whether a request failed due to an I/O error
51  * should be re-executed.
52  * <p>
53  * Further responsibilities such as communication with the opposite
54  * endpoint is delegated to the next executor in the request execution
55  * chain.
56  * </p>
57  *
58  * @since 4.3
59  */
60 @Contract(threading = ThreadingBehavior.IMMUTABLE_CONDITIONAL)
61 public class RetryExec implements ClientExecChain {
62
63     private final Log log = LogFactory.getLog(getClass());
64
65     private final ClientExecChain requestExecutor;
66     private final HttpRequestRetryHandler retryHandler;
67
68     public RetryExec(
69             final ClientExecChain requestExecutor,
70             final HttpRequestRetryHandler retryHandler) {
71         Args.notNull(requestExecutor, "HTTP request executor");
72         Args.notNull(retryHandler, "HTTP request retry handler");
73         this.requestExecutor = requestExecutor;
74         this.retryHandler = retryHandler;
75     }
76
77     @Override
78     public CloseableHttpResponse execute(
79             final HttpRoute route,
80             final HttpRequestWrapper request,
81             final HttpClientContext context,
82             final HttpExecutionAware execAware) throws IOException, HttpException {
83         Args.notNull(route, "HTTP route");
84         Args.notNull(request, "HTTP request");
85         Args.notNull(context, "HTTP context");
86         final Header[] origheaders = request.getAllHeaders();
87         for (int execCount = 1;; execCount++) {
88             try {
89                 return this.requestExecutor.execute(route, request, context, execAware);
90             } catch (final IOException ex) {
91                 if (execAware != null && execAware.isAborted()) {
92                     this.log.debug("Request has been aborted");
93                     throw ex;
94                 }
95                 if (retryHandler.retryRequest(ex, execCount, context)) {
96                     if (this.log.isInfoEnabled()) {
97                         this.log.info("I/O exception ("+ ex.getClass().getName() +
98                                 ") caught when processing request to "
99                                 + route +
100                                 ": "
101                                 + ex.getMessage());
102                     }
103                     if (this.log.isDebugEnabled()) {
104                         this.log.debug(ex.getMessage(), ex);
105                     }
106                     if (!RequestEntityProxy.isRepeatable(request)) {
107                         this.log.debug("Cannot retry non-repeatable request");
108                         throw new NonRepeatableRequestException("Cannot retry request " +
109                                 "with a non-repeatable request entity", ex);
110                     }
111                     request.setHeaders(origheaders);
112                     if (this.log.isInfoEnabled()) {
113                         this.log.info("Retrying request to " + route);
114                     }
115                 } else {
116                     if (ex instanceof NoHttpResponseException) {
117                         final NoHttpResponseException updatedex = new NoHttpResponseException(
118                                 route.getTargetHost().toHostString() + " failed to respond");
119                         updatedex.setStackTrace(ex.getStackTrace());
120                         throw updatedex;
121                     }
122                     throw ex;
123                 }
124             }
125         }
126     }
127
128 }
129