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.nio.protocol; 29 30 import java.io.Closeable; 31 import java.io.IOException; 32 33 import org.apache.http.HttpResponse; 34 import org.apache.http.nio.ContentEncoder; 35 import org.apache.http.nio.IOControl; 36 import org.apache.http.protocol.HttpContext; 37 38 /** 39 * {@code HttpAsyncResponseProducer} is a callback interface whose methods 40 * get invoked to generate an HTTP response message and to stream message 41 * content to a non-blocking HTTP connection on the server side. 42 * 43 * @since 4.2 44 */ 45 public interface HttpAsyncResponseProducer extends Closeable { 46 47 /** 48 * Invoked to generate a HTTP response message head. 49 * 50 * @return HTTP response message. 51 */ 52 HttpResponse generateResponse(); 53 54 /** 55 * Invoked to write out a chunk of content to the {@link ContentEncoder}. 56 * The {@link IOControl} interface can be used to suspend output event 57 * notifications if the producer is temporarily unable to produce more content. 58 * <p> 59 * When all content is finished, the producer <b>MUST</b> call 60 * {@link ContentEncoder#complete()}. Failure to do so may cause the entity 61 * to be incorrectly delimited. 62 * <p> 63 * Please note that the {@link ContentEncoder} object is not thread-safe and 64 * should only be used within the context of this method call. 65 * The {@link IOControl} object can be shared and used on other thread 66 * to resume output event notifications when more content is made available. 67 * 68 * @param encoder content encoder. 69 * @param ioControl I/O control of the underlying connection. 70 * @throws IOException in case of an I/O error 71 */ 72 void produceContent(ContentEncoder encoder, IOControl ioControl) throws IOException; 73 74 /** 75 * Invoked to signal that the response has been fully written out. 76 * 77 * @param context HTTP context 78 */ 79 void responseCompleted(HttpContext context); 80 81 /** 82 * Invoked to signal that the response processing terminated abnormally. 83 * 84 * @param ex exception 85 */ 86 void failed(Exception ex); 87 88 }