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.HttpResponse; 034import org.apache.http.HttpResponseInterceptor; 035import org.apache.http.annotation.ThreadingBehavior; 036import org.apache.http.annotation.Contract; 037import org.apache.http.util.Args; 038 039/** 040 * ResponseServer is responsible for adding {@code Server} header. This 041 * interceptor is recommended for server side protocol processors. 042 * 043 * @since 4.0 044 */ 045@Contract(threading = ThreadingBehavior.IMMUTABLE) 046public class ResponseServer implements HttpResponseInterceptor { 047 048 private final String originServer; 049 050 /** 051 * @since 4.3 052 */ 053 public ResponseServer(final String originServer) { 054 super(); 055 this.originServer = originServer; 056 } 057 058 public ResponseServer() { 059 this(null); 060 } 061 062 @Override 063 public void process(final HttpResponse response, final HttpContext context) 064 throws HttpException, IOException { 065 Args.notNull(response, "HTTP response"); 066 if (!response.containsHeader(HTTP.SERVER_HEADER)) { 067 if (this.originServer != null) { 068 response.addHeader(HTTP.SERVER_HEADER, this.originServer); 069 } 070 } 071 } 072 073}