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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  package org.apache.hc.client5.http.impl.classic;
28  
29  import java.net.ConnectException;
30  import java.net.SocketTimeoutException;
31  
32  import org.apache.hc.client5.http.classic.ConnectionBackoffStrategy;
33  import org.apache.hc.core5.annotation.Experimental;
34  import org.apache.hc.core5.http.HttpResponse;
35  import org.apache.hc.core5.http.HttpStatus;
36  
37  /**
38   * This {@link ConnectionBackoffStrategy} backs off either for a raw
39   * network socket or connection timeout or if the server explicitly
40   * sends a 429 (Too Many Requests) or a 503 (Service Unavailable) response.
41   *
42   * @since 4.2
43   */
44  @Experimental
45  public class DefaultBackoffStrategy implements ConnectionBackoffStrategy {
46  
47      @Override
48      public boolean shouldBackoff(final Throwable t) {
49          return t instanceof SocketTimeoutException || t instanceof ConnectException;
50      }
51  
52      @Override
53      public boolean shouldBackoff(final HttpResponse response) {
54          return response.getCode() == HttpStatus.SC_TOO_MANY_REQUESTS ||
55              response.getCode() == HttpStatus.SC_SERVICE_UNAVAILABLE;
56      }
57  
58  }