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 package org.apache.hc.core5.http.nio;
28
29 import java.io.IOException;
30
31 import org.apache.hc.core5.annotation.Contract;
32 import org.apache.hc.core5.annotation.ThreadingBehavior;
33 import org.apache.hc.core5.http.EntityDetails;
34 import org.apache.hc.core5.http.HttpException;
35 import org.apache.hc.core5.http.HttpRequest;
36 import org.apache.hc.core5.http.HttpResponse;
37 import org.apache.hc.core5.http.protocol.HttpContext;
38
39 /**
40 * AsyncServerRequestHandler represents a routine for processing of a specific group
41 * of HTTP requests. Request execution filters are designed to take care of protocol
42 * specific aspects, whereas individual request handlers are expected to take care
43 * of application specific HTTP processing. The main purpose of a request handler
44 * is to generate a response object with a content entity to be sent back to
45 * the client in response to the given request.
46 *
47 * @param <T> request representation.
48 *
49 * @since 5.0
50 */
51 @Contract(threading = ThreadingBehavior.STATELESS)
52 public interface AsyncServerRequestHandler<T> {
53
54 /**
55 * Response trigger that can be used to submit a final HTTP response
56 * and terminate HTTP request processing.
57 */
58 interface ResponseTrigger {
59
60 /**
61 * Sends an intermediate informational HTTP response to the client.
62 *
63 * @param response the intermediate (1xx) HTTP response
64 * @param context the actual execution context.
65 */
66 void sendInformation(HttpResponse response, HttpContext context) throws HttpException, IOException;
67
68 /**
69 * Sends a final HTTP response to the client.
70 *
71 * @param responseProducer the HTTP response message producer.
72 * @param context the actual execution context.
73 */
74 void submitResponse(AsyncResponseProducer responseProducer, HttpContext context) throws HttpException, IOException;
75
76 /**
77 * Pushes a request message head as a promise to deliver a response message.
78 *
79 * @param promise the request message header used as a promise.
80 * @param context the actual execution context.
81 * @param responseProducer the push response message producer.
82 */
83 void pushPromise(HttpRequest promise, HttpContext context, AsyncPushProducer responseProducer) throws HttpException, IOException;
84
85 }
86
87 /**
88 * Triggered to signal new incoming request. The handler can create a {@link AsyncRequestConsumer} based on
89 * properties of the request head and entity details and let it process the request data stream. The request
90 * handler will be used to generate an object that represents request data.
91 *
92 * @param request the incoming request head.
93 * @param entityDetails the request entity details or {@code null} if the request
94 * does not enclose an entity.
95 * @param context the actual execution context.
96 * @return the request handler.
97 */
98 AsyncRequestConsumer<T> prepare(HttpRequest request, EntityDetails entityDetails, HttpContext context) throws HttpException;
99
100 /**
101 * Triggered to handles the request object produced by the {@link AsyncRequestConsumer} returned
102 * from the {@link #prepare(HttpRequest, EntityDetails, HttpContext)} method. The handler can choose
103 * to send response messages immediately inside the call or asynchronously at some later point.
104 *
105 * @param requestObject the request object.
106 * @param responseTrigger the response trigger.
107 * @param context the actual execution context.
108 */
109 void handle(T requestObject, ResponseTrigger responseTrigger, HttpContext context) throws HttpException, IOException;
110
111 }