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.HttpStatus; 036import org.apache.http.annotation.ThreadingBehavior; 037import org.apache.http.annotation.Contract; 038import org.apache.http.util.Args; 039 040/** 041 * ResponseDate is responsible for adding {@code Date} header to the 042 * outgoing responses. This interceptor is recommended for server side protocol 043 * processors. 044 * 045 * @since 4.0 046 */ 047@Contract(threading = ThreadingBehavior.SAFE) 048public class ResponseDate implements HttpResponseInterceptor { 049 050 private static final HttpDateGenerator DATE_GENERATOR = new HttpDateGenerator(); 051 052 public ResponseDate() { 053 super(); 054 } 055 056 @Override 057 public void process(final HttpResponse response, final HttpContext context) 058 throws HttpException, IOException { 059 Args.notNull(response, "HTTP response"); 060 final int status = response.getStatusLine().getStatusCode(); 061 if ((status >= HttpStatus.SC_OK) && 062 !response.containsHeader(HTTP.DATE_HEADER)) { 063 final String httpdate = DATE_GENERATOR.getCurrentDate(); 064 response.setHeader(HTTP.DATE_HEADER, httpdate); 065 } 066 } 067 068}