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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.client;
29  
30  import java.util.Locale;
31  import java.util.Map;
32  import java.util.concurrent.ConcurrentHashMap;
33  
34  import org.apache.http.HttpRequest;
35  import org.apache.http.annotation.Immutable;
36  
37  /**
38   * {@link org.apache.http.client.HttpRequestRetryHandler} which assumes
39   * that all requested HTTP methods which should be idempotent according
40   * to RFC-2616 are in fact idempotent and can be retried.
41   * <p>
42   * According to RFC-2616 section 9.1.2 the idempotent HTTP methods are:
43   * GET, HEAD, PUT, DELETE, OPTIONS, and TRACE
44   * </p>
45   *
46   * @since 4.2
47   */
48  @Immutable
49  public class StandardHttpRequestRetryHandler extends DefaultHttpRequestRetryHandler {
50  
51      private final Map<String, Boolean> idempotentMethods;
52  
53      /**
54       * Default constructor
55       */
56      public StandardHttpRequestRetryHandler(final int retryCount, final boolean requestSentRetryEnabled) {
57          super(retryCount, requestSentRetryEnabled);
58          this.idempotentMethods = new ConcurrentHashMap<String, Boolean>();
59          this.idempotentMethods.put("GET", Boolean.TRUE);
60          this.idempotentMethods.put("HEAD", Boolean.TRUE);
61          this.idempotentMethods.put("PUT", Boolean.TRUE);
62          this.idempotentMethods.put("DELETE", Boolean.TRUE);
63          this.idempotentMethods.put("OPTIONS", Boolean.TRUE);
64          this.idempotentMethods.put("TRACE", Boolean.TRUE);
65      }
66  
67      /**
68       * Default constructor
69       */
70      public StandardHttpRequestRetryHandler() {
71          this(3, false);
72      }
73  
74      @Override
75      protected boolean handleAsIdempotent(final HttpRequest request) {
76          final String method = request.getRequestLine().getMethod().toUpperCase(Locale.ROOT);
77          final Boolean b = this.idempotentMethods.get(method);
78          return b != null && b.booleanValue();
79      }
80  
81  }