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.HttpEntity; 033import org.apache.http.HttpEntityEnclosingRequest; 034import org.apache.http.HttpException; 035import org.apache.http.HttpRequest; 036import org.apache.http.HttpRequestInterceptor; 037import org.apache.http.HttpVersion; 038import org.apache.http.ProtocolVersion; 039import org.apache.http.annotation.ThreadingBehavior; 040import org.apache.http.annotation.Contract; 041import org.apache.http.params.CoreProtocolPNames; 042import org.apache.http.util.Args; 043 044/** 045 * RequestExpectContinue is responsible for enabling the 'expect-continue' 046 * handshake by adding {@code Expect} header. This interceptor is 047 * recommended for client side protocol processors. 048 * 049 * @since 4.0 050 */ 051@Contract(threading = ThreadingBehavior.IMMUTABLE) 052@SuppressWarnings("deprecation") 053public class RequestExpectContinue implements HttpRequestInterceptor { 054 055 private final boolean activeByDefault; 056 057 /** 058 * @deprecated (4.3) use {@link org.apache.http.protocol.RequestExpectContinue#RequestExpectContinue(boolean)} 059 */ 060 @Deprecated 061 public RequestExpectContinue() { 062 this(false); 063 } 064 065 /** 066 * @since 4.3 067 */ 068 public RequestExpectContinue(final boolean activeByDefault) { 069 super(); 070 this.activeByDefault = activeByDefault; 071 } 072 073 @Override 074 public void process(final HttpRequest request, final HttpContext context) 075 throws HttpException, IOException { 076 Args.notNull(request, "HTTP request"); 077 078 if (!request.containsHeader(HTTP.EXPECT_DIRECTIVE)) { 079 if (request instanceof HttpEntityEnclosingRequest) { 080 final ProtocolVersion ver = request.getRequestLine().getProtocolVersion(); 081 final HttpEntity entity = ((HttpEntityEnclosingRequest)request).getEntity(); 082 // Do not send the expect header if request body is known to be empty 083 if (entity != null 084 && entity.getContentLength() != 0 && !ver.lessEquals(HttpVersion.HTTP_1_0)) { 085 final boolean active = request.getParams().getBooleanParameter( 086 CoreProtocolPNames.USE_EXPECT_CONTINUE, this.activeByDefault); 087 if (active) { 088 request.addHeader(HTTP.EXPECT_DIRECTIVE, HTTP.EXPECT_CONTINUE); 089 } 090 } 091 } 092 } 093 } 094 095}