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.protocol;
29
30 import java.io.IOException;
31
32 import org.apache.http.HttpEntity;
33 import org.apache.http.HttpEntityEnclosingRequest;
34 import org.apache.http.HttpException;
35 import org.apache.http.HttpRequest;
36 import org.apache.http.HttpRequestInterceptor;
37 import org.apache.http.HttpVersion;
38 import org.apache.http.ProtocolVersion;
39 import org.apache.http.annotation.ThreadingBehavior;
40 import org.apache.http.annotation.Contract;
41 import org.apache.http.params.CoreProtocolPNames;
42 import org.apache.http.util.Args;
43
44 /**
45 * RequestExpectContinue is responsible for enabling the 'expect-continue'
46 * handshake by adding {@code Expect} header. This interceptor is
47 * recommended for client side protocol processors.
48 *
49 * @since 4.0
50 */
51 @Contract(threading = ThreadingBehavior.IMMUTABLE)
52 @SuppressWarnings("deprecation")
53 public class RequestExpectContinue implements HttpRequestInterceptor {
54
55 private final boolean activeByDefault;
56
57 /**
58 * @deprecated (4.3) use {@link org.apache.http.protocol.RequestExpectContinue#RequestExpectContinue(boolean)}
59 */
60 @Deprecated
61 public RequestExpectContinue() {
62 this(false);
63 }
64
65 /**
66 * @since 4.3
67 */
68 public RequestExpectContinue(final boolean activeByDefault) {
69 super();
70 this.activeByDefault = activeByDefault;
71 }
72
73 @Override
74 public void process(final HttpRequest request, final HttpContext context)
75 throws HttpException, IOException {
76 Args.notNull(request, "HTTP request");
77
78 if (!request.containsHeader(HTTP.EXPECT_DIRECTIVE)) {
79 if (request instanceof HttpEntityEnclosingRequest) {
80 final ProtocolVersion ver = request.getRequestLine().getProtocolVersion();
81 final HttpEntity entity = ((HttpEntityEnclosingRequest)request).getEntity();
82 // Do not send the expect header if request body is known to be empty
83 if (entity != null
84 && entity.getContentLength() != 0 && !ver.lessEquals(HttpVersion.HTTP_1_0)) {
85 final boolean active = request.getParams().getBooleanParameter(
86 CoreProtocolPNames.USE_EXPECT_CONTINUE, this.activeByDefault);
87 if (active) {
88 request.addHeader(HTTP.EXPECT_DIRECTIVE, HTTP.EXPECT_CONTINUE);
89 }
90 }
91 }
92 }
93 }
94
95 }