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.protocol;
29
30 import java.io.IOException;
31
32 import org.apache.hc.client5.http.config.RequestConfig;
33 import org.apache.hc.core5.annotation.Contract;
34 import org.apache.hc.core5.annotation.ThreadingBehavior;
35 import org.apache.hc.core5.http.EntityDetails;
36 import org.apache.hc.core5.http.HeaderElements;
37 import org.apache.hc.core5.http.HttpException;
38 import org.apache.hc.core5.http.HttpHeaders;
39 import org.apache.hc.core5.http.HttpRequest;
40 import org.apache.hc.core5.http.HttpRequestInterceptor;
41 import org.apache.hc.core5.http.HttpVersion;
42 import org.apache.hc.core5.http.ProtocolVersion;
43 import org.apache.hc.core5.http.protocol.HttpContext;
44 import org.apache.hc.core5.util.Args;
45
46 /**
47 * RequestExpectContinue is responsible for enabling the 'expect-continue'
48 * handshake by adding {@code Expect} header.
49 * <p>
50 * This interceptor takes into account {@link RequestConfig#isExpectContinueEnabled()}
51 * setting.
52 * </p>
53 *
54 * @since 4.3
55 */
56 @Contract(threading = ThreadingBehavior.STATELESS)
57 public class RequestExpectContinue implements HttpRequestInterceptor {
58
59 public RequestExpectContinue() {
60 super();
61 }
62
63 @Override
64 public void process(final HttpRequest request, final EntityDetails entity, final HttpContext context)
65 throws HttpException, IOException {
66 Args.notNull(request, "HTTP request");
67
68 if (!request.containsHeader(HttpHeaders.EXPECT)) {
69 final ProtocolVersion version = request.getVersion() != null ? request.getVersion() : HttpVersion.HTTP_1_1;
70 // Do not send the expect header if request body is known to be empty
71 if (entity != null
72 && entity.getContentLength() != 0 && !version.lessEquals(HttpVersion.HTTP_1_0)) {
73 final HttpClientContext clientContext = HttpClientContext.adapt(context);
74 final RequestConfig config = clientContext.getRequestConfig();
75 if (config.isExpectContinueEnabled()) {
76 request.addHeader(HttpHeaders.EXPECT, HeaderElements.CONTINUE);
77 }
78 }
79 }
80 }
81
82 }