001/* 002 * ==================================================================== 003 * Licensed to the Apache Software Foundation (ASF) under one 004 * or more contributor license agreements. See the NOTICE file 005 * distributed with this work for additional information 006 * regarding copyright ownership. The ASF licenses this file 007 * to you under the Apache License, Version 2.0 (the 008 * "License"); you may not use this file except in compliance 009 * with the License. You may obtain a copy of the License at 010 * 011 * http://www.apache.org/licenses/LICENSE-2.0 012 * 013 * Unless required by applicable law or agreed to in writing, 014 * software distributed under the License is distributed on an 015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 016 * KIND, either express or implied. See the License for the 017 * specific language governing permissions and limitations 018 * under the License. 019 * ==================================================================== 020 * 021 * This software consists of voluntary contributions made by many 022 * individuals on behalf of the Apache Software Foundation. For more 023 * information on the Apache Software Foundation, please see 024 * <http://www.apache.org/>. 025 * 026 */ 027 028package org.apache.http.impl.client; 029 030import org.apache.http.HttpResponse; 031import org.apache.http.HttpStatus; 032import org.apache.http.annotation.Contract; 033import org.apache.http.annotation.ThreadingBehavior; 034import org.apache.http.client.ServiceUnavailableRetryStrategy; 035import org.apache.http.protocol.HttpContext; 036import org.apache.http.util.Args; 037 038/** 039 * Default implementation of the {@link ServiceUnavailableRetryStrategy} interface. 040 * that retries {@code 503} (Service Unavailable) responses for a fixed number of times 041 * at a fixed interval. 042 * 043 * @since 4.2 044 */ 045@Contract(threading = ThreadingBehavior.IMMUTABLE) 046public class DefaultServiceUnavailableRetryStrategy implements ServiceUnavailableRetryStrategy { 047 048 /** 049 * Maximum number of allowed retries if the server responds with a HTTP code 050 * in our retry code list. Default value is 1. 051 */ 052 private final int maxRetries; 053 054 /** 055 * Retry interval between subsequent requests, in milliseconds. Default 056 * value is 1 second. 057 */ 058 private final long retryInterval; 059 060 public DefaultServiceUnavailableRetryStrategy(final int maxRetries, final int retryInterval) { 061 super(); 062 Args.positive(maxRetries, "Max retries"); 063 Args.positive(retryInterval, "Retry interval"); 064 this.maxRetries = maxRetries; 065 this.retryInterval = retryInterval; 066 } 067 068 public DefaultServiceUnavailableRetryStrategy() { 069 this(1, 1000); 070 } 071 072 @Override 073 public boolean retryRequest(final HttpResponse response, final int executionCount, final HttpContext context) { 074 return executionCount <= maxRetries && 075 response.getStatusLine().getStatusCode() == HttpStatus.SC_SERVICE_UNAVAILABLE; 076 } 077 078 @Override 079 public long getRetryInterval() { 080 return retryInterval; 081 } 082 083}