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.IOException;
31
32 import org.apache.http.HttpEntity;
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.nio.entity.EntityAsyncContentProducer;
37 import org.apache.http.nio.entity.HttpAsyncContentProducer;
38 import org.apache.http.protocol.HttpContext;
39 import org.apache.http.util.Args;
40
41 /**
42 * Basic implementation of {@link HttpAsyncResponseProducer}. The producer
43 * can make use of the {@link HttpAsyncContentProducer} interface to
44 * efficiently stream out message content to the underlying non-blocking HTTP
45 * connection, if it is implemented by the {@link HttpEntity} inclosed in
46 * the response.
47 *
48 * @see HttpAsyncContentProducer
49 *
50 * @since 4.2
51 */
52 public class BasicAsyncResponseProducer implements HttpAsyncResponseProducer {
53
54 private final HttpResponse response;
55 private final HttpAsyncContentProducer producer;
56
57 /**
58 * Creates a producer that can be used to transmit the given response
59 * message. The given content producer will be used to stream out message
60 * content. Please note that the response message is expected to enclose
61 * an {@link HttpEntity} whose properties are consistent with the behavior
62 * of the content producer.
63 *
64 * @param response response message.
65 * @param producer response content producer.
66 */
67 protected BasicAsyncResponseProducer(
68 final HttpResponse response,
69 final HttpAsyncContentProducer producer) {
70 super();
71 Args.notNull(response, "HTTP response");
72 Args.notNull(producer, "HTTP content producer");
73 this.response = response;
74 this.producer = producer;
75 }
76
77 /**
78 * Creates a producer that can be used to transmit the given response
79 * message. If the response message encloses an {@link HttpEntity}
80 * it is also expected to implement {@link HttpAsyncContentProducer}.
81 *
82 * @param response response message.
83 */
84 public BasicAsyncResponseProducer(final HttpResponse response) {
85 super();
86 Args.notNull(response, "HTTP response");
87 this.response = response;
88 final HttpEntity entity = response.getEntity();
89 if (entity != null) {
90 if (entity instanceof HttpAsyncContentProducer) {
91 this.producer = (HttpAsyncContentProducer) entity;
92 } else {
93 this.producer = new EntityAsyncContentProducer(entity);
94 }
95 } else {
96 this.producer = null;
97 }
98 }
99
100 @Override
101 public HttpResponse generateResponse() {
102 return this.response;
103 }
104
105 @Override
106 public void produceContent(
107 final ContentEncoder encoder, final IOControl ioControl) throws IOException {
108 if (this.producer != null) {
109 this.producer.produceContent(encoder, ioControl);
110 if (encoder.isCompleted()) {
111 this.producer.close();
112 }
113 }
114 }
115
116 @Override
117 public void responseCompleted(final HttpContext context) {
118 }
119
120 @Override
121 public void failed(final Exception ex) {
122 }
123
124 @Override
125 public void close() throws IOException {
126 if (this.producer != null) {
127 this.producer.close();
128 }
129 }
130
131 @Override
132 public String toString() {
133 final StringBuilder buf = new StringBuilder();
134 buf.append(this.response);
135 if (this.producer != null) {
136 buf.append(" ").append(this.producer);
137 }
138 return buf.toString();
139 }
140
141 }