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.protocol; 029 030import java.io.IOException; 031 032import org.apache.http.HttpException; 033import org.apache.http.HttpRequest; 034import org.apache.http.HttpRequestInterceptor; 035import org.apache.http.annotation.ThreadingBehavior; 036import org.apache.http.annotation.Contract; 037import org.apache.http.util.Args; 038 039/** 040 * RequestConnControl is responsible for adding {@code Connection} header 041 * to the outgoing requests, which is essential for managing persistence of 042 * {@code HTTP/1.0} connections. This interceptor is recommended for 043 * client side protocol processors. 044 * 045 * @since 4.0 046 */ 047@Contract(threading = ThreadingBehavior.IMMUTABLE) 048public class RequestConnControl implements HttpRequestInterceptor { 049 050 public RequestConnControl() { 051 super(); 052 } 053 054 @Override 055 public void process(final HttpRequest request, final HttpContext context) 056 throws HttpException, IOException { 057 Args.notNull(request, "HTTP request"); 058 059 final String method = request.getRequestLine().getMethod(); 060 if (method.equalsIgnoreCase("CONNECT")) { 061 return; 062 } 063 064 if (!request.containsHeader(HTTP.CONN_DIRECTIVE)) { 065 // Default policy is to keep connection alive 066 // whenever possible 067 request.addHeader(HTTP.CONN_DIRECTIVE, HTTP.CONN_KEEP_ALIVE); 068 } 069 } 070 071}