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.client5.http.async;
28
29 import java.io.IOException;
30
31 import org.apache.hc.client5.http.impl.ChainElement;
32 import org.apache.hc.client5.http.impl.async.AsyncHttpRequestRetryExec;
33 import org.apache.hc.client5.http.impl.async.HttpAsyncClientBuilder;
34 import org.apache.hc.core5.annotation.Contract;
35 import org.apache.hc.core5.annotation.ThreadingBehavior;
36 import org.apache.hc.core5.http.HttpException;
37 import org.apache.hc.core5.http.HttpRequest;
38 import org.apache.hc.core5.http.nio.AsyncEntityProducer;
39
40 /**
41 * Abstract request execution handler in an asynchronous client side request execution
42 * chain. Handlers can either be a decorator around another element that implements
43 * a cross cutting aspect or a self-contained executor capable of producing a response
44 * for the given request.
45 * <p>
46 * For information regarding the handler chain behaviour in case of a request re-execution,
47 * please refer to the {@link AsyncHttpRequestRetryExec} javadoc.
48 * </p>
49 * <p>
50 * Well known request execution handlers could be referred to by name using one of the
51 * {@link ChainElement} enum values.
52 * </p>
53 * @since 5.0
54 * @see ChainElement
55 * @see HttpAsyncClientBuilder#addExecInterceptorFirst(String, AsyncExecChainHandler)
56 * @see HttpAsyncClientBuilder#addExecInterceptorBefore(String, String, AsyncExecChainHandler)
57 * @see HttpAsyncClientBuilder#addExecInterceptorAfter(String, String, AsyncExecChainHandler)
58 * @see HttpAsyncClientBuilder#addExecInterceptorLast(String, AsyncExecChainHandler)
59 */
60 @Contract(threading = ThreadingBehavior.STATELESS)
61 public interface AsyncExecChainHandler {
62
63 /**
64 * Executes the actual HTTP request. The handler can choose to return
65 * a response message immediately inside the call or asynchronously
66 * at some later point or delegate request execution to the next
67 * element in the execution chain.
68 *
69 * @param request the actual request.
70 * @param entityProducer the request entity producer or {@code null} if the request
71 * does not enclose an entity.
72 * @param scope the execution scope .
73 * @param chain the next element in the request execution chain.
74 * @param asyncExecCallback the execution callback.
75 */
76 void execute(
77 HttpRequest request,
78 AsyncEntityProducer entityProducer,
79 AsyncExecChain.Scope scope,
80 AsyncExecChain chain,
81 AsyncExecCallback asyncExecCallback) throws HttpException, IOException;
82
83 }