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 org.apache.http.HttpResponse;
31 import org.apache.http.HttpStatus;
32 import org.apache.http.annotation.Contract;
33 import org.apache.http.annotation.ThreadingBehavior;
34 import org.apache.http.client.ServiceUnavailableRetryStrategy;
35 import org.apache.http.protocol.HttpContext;
36 import org.apache.http.util.Args;
37
38 /**
39 * Default implementation of the {@link ServiceUnavailableRetryStrategy} interface.
40 * that retries {@code 503} (Service Unavailable) responses for a fixed number of times
41 * at a fixed interval.
42 *
43 * @since 4.2
44 */
45 @Contract(threading = ThreadingBehavior.IMMUTABLE)
46 public class DefaultServiceUnavailableRetryStrategy implements ServiceUnavailableRetryStrategy {
47
48 /**
49 * Maximum number of allowed retries if the server responds with a HTTP code
50 * in our retry code list. Default value is 1.
51 */
52 private final int maxRetries;
53
54 /**
55 * Retry interval between subsequent requests, in milliseconds. Default
56 * value is 1 second.
57 */
58 private final long retryInterval;
59
60 public DefaultServiceUnavailableRetryStrategy(final int maxRetries, final int retryInterval) {
61 super();
62 Args.positive(maxRetries, "Max retries");
63 Args.positive(retryInterval, "Retry interval");
64 this.maxRetries = maxRetries;
65 this.retryInterval = retryInterval;
66 }
67
68 public DefaultServiceUnavailableRetryStrategy() {
69 this(1, 1000);
70 }
71
72 @Override
73 public boolean retryRequest(final HttpResponse response, final int executionCount, final HttpContext context) {
74 return executionCount <= maxRetries &&
75 response.getStatusLine().getStatusCode() == HttpStatus.SC_SERVICE_UNAVAILABLE;
76 }
77
78 @Override
79 public long getRetryInterval() {
80 return retryInterval;
81 }
82
83 }