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.nio.protocol; 029 030import java.io.Closeable; 031import java.io.IOException; 032 033import org.apache.http.HttpResponse; 034import org.apache.http.nio.ContentEncoder; 035import org.apache.http.nio.IOControl; 036import org.apache.http.protocol.HttpContext; 037 038/** 039 * {@code HttpAsyncResponseProducer} is a callback interface whose methods 040 * get invoked to generate an HTTP response message and to stream message 041 * content to a non-blocking HTTP connection on the server side. 042 * 043 * @since 4.2 044 */ 045public interface HttpAsyncResponseProducer extends Closeable { 046 047 /** 048 * Invoked to generate a HTTP response message head. 049 * 050 * @return HTTP response message. 051 */ 052 HttpResponse generateResponse(); 053 054 /** 055 * Invoked to write out a chunk of content to the {@link ContentEncoder}. 056 * The {@link IOControl} interface can be used to suspend output event 057 * notifications if the producer is temporarily unable to produce more content. 058 * <p> 059 * When all content is finished, the producer <b>MUST</b> call 060 * {@link ContentEncoder#complete()}. Failure to do so may cause the entity 061 * to be incorrectly delimited. 062 * <p> 063 * Please note that the {@link ContentEncoder} object is not thread-safe and 064 * should only be used within the context of this method call. 065 * The {@link IOControl} object can be shared and used on other thread 066 * to resume output event notifications when more content is made available. 067 * 068 * @param encoder content encoder. 069 * @param ioctrl I/O control of the underlying connection. 070 * @throws IOException in case of an I/O error 071 */ 072 void produceContent(ContentEncoder encoder, IOControl ioctrl) throws IOException; 073 074 /** 075 * Invoked to signal that the response has been fully written out. 076 * 077 * @param context HTTP context 078 */ 079 void responseCompleted(HttpContext context); 080 081 /** 082 * Invoked to signal that the response processing terminated abnormally. 083 * 084 * @param ex exception 085 */ 086 void failed(Exception ex); 087 088}