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.support;
28
29 import java.util.concurrent.atomic.AtomicReference;
30
31 import org.apache.hc.core5.annotation.Internal;
32 import org.apache.hc.core5.http.EntityDetails;
33 import org.apache.hc.core5.http.HeaderElements;
34 import org.apache.hc.core5.http.HttpHeaders;
35 import org.apache.hc.core5.http.HttpRequest;
36 import org.apache.hc.core5.http.HttpVersion;
37 import org.apache.hc.core5.http.ProtocolException;
38 import org.apache.hc.core5.http.message.MessageSupport;
39 import org.apache.hc.core5.util.TextUtils;
40
41 /**
42 * Server side Expect header handling support.
43 *
44 * @since 5.3
45 */
46 @Internal
47 public class ExpectSupport {
48
49 public static Expectation parse(
50 final HttpRequest request,
51 final EntityDetails entityDetails) throws ProtocolException {
52 // Ignore Expect header in messages older than HTTP/1.1
53 if (request.getVersion() != null && request.getVersion().lessEquals(HttpVersion.HTTP_1_0)) {
54 return null;
55 }
56 final AtomicReference<Expectation> expectationRef = new AtomicReference<>();
57 MessageSupport.parseTokens(request, HttpHeaders.EXPECT, t -> {
58 if (t.equalsIgnoreCase(HeaderElements.CONTINUE)) {
59 expectationRef.compareAndSet(null, Expectation.CONTINUE);
60 } else if (!TextUtils.isBlank(t)) {
61 expectationRef.set(Expectation.UNKNOWN);
62 }
63 });
64 final Expectation expectation = expectationRef.get();
65 if (expectation == Expectation.CONTINUE && entityDetails == null) {
66 throw new ProtocolException("Expect-Continue request without an enclosed entity");
67 }
68 return expectation;
69 }
70 }
71