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.hc.client5.http.classic;
29
30 import java.io.IOException;
31
32 import org.apache.hc.core5.annotation.Contract;
33 import org.apache.hc.core5.annotation.ThreadingBehavior;
34 import org.apache.hc.core5.http.ClassicHttpRequest;
35 import org.apache.hc.core5.http.ClassicHttpResponse;
36 import org.apache.hc.core5.http.HttpException;
37
38 /**
39 * Abstract request execution handler in a classic client side request execution chain.
40 * Handlers can either be a decorator around another element that implements a cross
41 * cutting aspect or a self-contained executor capable of producing a response
42 * for the given request.
43 * <p>
44 * Important: please note it is required for decorators that implement post execution aspects
45 * or response post-processing of any sort to release resources associated with the response
46 * by calling {@link ClassicHttpResponse#close()} methods in case of an I/O, protocol or
47 * runtime exception, or in case the response is not propagated to the caller.
48 * </p>
49 *
50 * @since 4.3
51 */
52 @Contract(threading = ThreadingBehavior.STATELESS)
53 public interface ExecChainHandler {
54
55 /**
56 * Executes the actual HTTP request. The handler can choose to return
57 * a response message or delegate request execution to the next element
58 * in the execution chain.
59 *
60 * @param request the actual request.
61 * @param scope the execution scope .
62 * @param chain the next element in the request execution chain.
63 */
64 ClassicHttpResponse execute(
65 ClassicHttpRequest request,
66 ExecChain.Scope scope,
67 ExecChain chain) throws IOException, HttpException;
68
69 }