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 org.apache.http.HttpRequest;
31 import org.apache.http.HttpResponse;
32 import org.apache.http.concurrent.Cancellable;
33
34 /**
35 * {@code HttpAsyncExchange} represents a server-side HTTP message exchange
36 * where an HTTP response can be deferred without blocking the I/O event thread
37 * and triggered asynchronously at a later point of later time.
38 *
39 * @since 4.2
40 */
41 public interface HttpAsyncExchange {
42
43 /**
44 * Returns the received HTTP request message.
45 *
46 * @return received HTTP request message.
47 */
48 HttpRequest getRequest();
49
50 /**
51 * Returns the default HTTP response message. Once ready the response
52 * message can submitted using {@link #submitResponse()} method.
53 *
54 * @return default HTTP response message.
55 */
56 HttpResponse getResponse();
57
58 /**
59 * Submits the default HTTP response and completed the message exchange.
60 * If the response encloses an {@link org.apache.http.HttpEntity} instance
61 * the entity is also expected to implement the
62 * {@link org.apache.http.nio.entity.HttpAsyncContentProducer }
63 * interface for efficient content streaming to a non-blocking HTTP
64 * connection.
65 *
66 * @throws IllegalStateException if a response has already been submitted.
67 */
68 void submitResponse();
69
70 /**
71 * Submits an HTTP response using a custom
72 * {@link HttpAsyncResponseProducer}.
73 *
74 * @throws IllegalStateException if a response has already been submitted.
75 */
76 void submitResponse(HttpAsyncResponseProducer responseProducer);
77
78 /**
79 * Determines whether or not the message exchange has been completed.
80 *
81 * @return {@code true} if the message exchange has been completed,
82 * {@code false} otherwise.
83 */
84 boolean isCompleted();
85
86 /**
87 * Sets {@link Cancellable} callback to be invoked in case the underlying
88 * connection times out or gets terminated prematurely by the client. This
89 * callback can be used to cancel a long running response generating
90 * process if a response is no longer needed.
91 */
92 void setCallback(Cancellable cancellable);
93
94 /**
95 * Sets timeout for this message exchange.
96 */
97 void setTimeout(int timeout);
98
99 /**
100 * Returns timeout for this message exchange.
101 */
102 int getTimeout();
103
104 }