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.core5.http.io.support;
29
30 import java.io.IOException;
31
32 import org.apache.hc.core5.http.ClassicHttpRequest;
33 import org.apache.hc.core5.http.ClassicHttpResponse;
34 import org.apache.hc.core5.http.Header;
35 import org.apache.hc.core5.http.HeaderElements;
36 import org.apache.hc.core5.http.HttpException;
37 import org.apache.hc.core5.http.HttpHeaders;
38 import org.apache.hc.core5.http.HttpStatus;
39 import org.apache.hc.core5.http.io.HttpServerRequestHandler;
40 import org.apache.hc.core5.http.message.BasicClassicHttpResponse;
41 import org.apache.hc.core5.http.protocol.HttpContext;
42 import org.apache.hc.core5.util.Args;
43
44 /**
45 * {@link HttpServerRequestHandler} implementation that adds support
46 * for the Expect-Continue handshake to an existing
47 * {@link HttpServerRequestHandler}.
48 *
49 * @since 5.0
50 */
51 public class BasicHttpServerExpectationDecorator implements HttpServerRequestHandler {
52
53 private final HttpServerRequestHandler requestHandler;
54
55 public BasicHttpServerExpectationDecorator(final HttpServerRequestHandler requestHandler) {
56 this.requestHandler = Args.notNull(requestHandler, "Request handler");
57 }
58
59 /**
60 * Verifies the HTTP request and decides whether it meets server expectations and the request
61 * processing can continue.
62 *
63 * @param request the incoming HTTP request.
64 * @param context the actual execution context.
65 * @return {@code null} if the request meets expectations or a final HTTP response
66 * with an error status representing the cause of expectation failure.
67 */
68 protected ClassicHttpResponse verify(final ClassicHttpRequest request, final HttpContext context) {
69 return null;
70 }
71
72 @Override
73 public final void handle(
74 final ClassicHttpRequest request,
75 final ResponseTrigger responseTrigger,
76 final HttpContext context) throws HttpException, IOException {
77 final Header expect = request.getFirstHeader(HttpHeaders.EXPECT);
78 if (expect != null && HeaderElements.CONTINUE.equalsIgnoreCase(expect.getValue())) {
79 final ClassicHttpResponse response = verify(request, context);
80 if (response == null) {
81 responseTrigger.sendInformation(new BasicClassicHttpResponse(HttpStatus.SC_CONTINUE));
82 } else {
83 responseTrigger.submitResponse(response);
84 return;
85 }
86 }
87 requestHandler.handle(request, responseTrigger, context);
88 }
89
90 }