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; 029 030import org.apache.http.protocol.HttpContext; 031 032/** 033 * Interface for deciding whether a connection can be re-used for 034 * subsequent requests and should be kept alive. 035 * <p> 036 * Implementations of this interface must be thread-safe. Access to shared 037 * data must be synchronized as methods of this interface may be executed 038 * from multiple threads. 039 * 040 * @since 4.0 041 */ 042public interface ConnectionReuseStrategy { 043 044 /** 045 * Decides whether a connection can be kept open after a request. 046 * If this method returns {@code false}, the caller MUST 047 * close the connection to correctly comply with the HTTP protocol. 048 * If it returns {@code true}, the caller SHOULD attempt to 049 * keep the connection open for reuse with another request. 050 * <p> 051 * One can use the HTTP context to retrieve additional objects that 052 * may be relevant for the keep-alive strategy: the actual HTTP 053 * connection, the original HTTP request, target host if known, 054 * number of times the connection has been reused already and so on. 055 * </p> 056 * <p> 057 * If the connection is already closed, {@code false} is returned. 058 * The stale connection check MUST NOT be triggered by a 059 * connection reuse strategy. 060 * </p> 061 * 062 * @param response 063 * The last response received over that connection. 064 * @param context the context in which the connection is being 065 * used. 066 * 067 * @return {@code true} if the connection is allowed to be reused, or 068 * {@code false} if it MUST NOT be reused 069 */ 070 boolean keepAlive(HttpResponse response, HttpContext context); 071 072}