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.protocol; 29 30 import java.io.IOException; 31 32 import org.apache.http.HttpException; 33 import org.apache.http.HttpRequest; 34 import org.apache.http.HttpRequestInterceptor; 35 import org.apache.http.annotation.ThreadingBehavior; 36 import org.apache.http.annotation.Contract; 37 import org.apache.http.util.Args; 38 39 /** 40 * RequestConnControl is responsible for adding {@code Connection} header 41 * to the outgoing requests, which is essential for managing persistence of 42 * {@code HTTP/1.0} connections. This interceptor is recommended for 43 * client side protocol processors. 44 * 45 * @since 4.0 46 */ 47 @Contract(threading = ThreadingBehavior.IMMUTABLE) 48 public class RequestConnControl implements HttpRequestInterceptor { 49 50 public RequestConnControl() { 51 super(); 52 } 53 54 @Override 55 public void process(final HttpRequest request, final HttpContext context) 56 throws HttpException, IOException { 57 Args.notNull(request, "HTTP request"); 58 59 final String method = request.getRequestLine().getMethod(); 60 if (method.equalsIgnoreCase("CONNECT")) { 61 return; 62 } 63 64 if (!request.containsHeader(HTTP.CONN_DIRECTIVE)) { 65 // Default policy is to keep connection alive 66 // whenever possible 67 request.addHeader(HTTP.CONN_DIRECTIVE, HTTP.CONN_KEEP_ALIVE); 68 } 69 } 70 71 }