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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.nio.support;
28  
29  import java.io.IOException;
30  
31  import org.apache.hc.core5.annotation.Contract;
32  import org.apache.hc.core5.annotation.ThreadingBehavior;
33  import org.apache.hc.core5.http.EntityDetails;
34  import org.apache.hc.core5.http.Header;
35  import org.apache.hc.core5.http.HttpException;
36  import org.apache.hc.core5.http.HttpHeaders;
37  import org.apache.hc.core5.http.HttpRequest;
38  import org.apache.hc.core5.http.HttpResponse;
39  import org.apache.hc.core5.http.HttpStatus;
40  import org.apache.hc.core5.http.message.BasicHttpResponse;
41  import org.apache.hc.core5.http.nio.AsyncDataConsumer;
42  import org.apache.hc.core5.http.nio.AsyncEntityProducer;
43  import org.apache.hc.core5.http.nio.AsyncFilterChain;
44  import org.apache.hc.core5.http.nio.AsyncFilterHandler;
45  import org.apache.hc.core5.http.protocol.HttpContext;
46  
47  /**
48   * @since 5.0
49   */
50  @Contract(threading = ThreadingBehavior.STATELESS)
51  public class AsyncServerExpectationFilter implements AsyncFilterHandler {
52  
53      protected boolean verify(final HttpRequest request, final HttpContext context) throws HttpException {
54          return true;
55      }
56  
57      protected AsyncEntityProducer generateResponseContent(final HttpResponse expectationFailed) throws HttpException {
58          return null;
59      }
60  
61      @Override
62      public AsyncDataConsumer handle(
63              final HttpRequest request,
64              final EntityDetails entityDetails,
65              final HttpContext context,
66              final AsyncFilterChain.ResponseTrigger responseTrigger,
67              final AsyncFilterChain chain) throws HttpException, IOException {
68          if (entityDetails != null) {
69              final Header h = request.getFirstHeader(HttpHeaders.EXPECT);
70              if (h != null && "100-continue".equalsIgnoreCase(h.getValue())) {
71                  final boolean verified = verify(request, context);
72                  if (verified) {
73                      responseTrigger.sendInformation(new BasicHttpResponse(HttpStatus.SC_CONTINUE));
74                  } else {
75                      final HttpResponse expectationFailed = new BasicHttpResponse(HttpStatus.SC_EXPECTATION_FAILED);
76                      final AsyncEntityProducer responseContentProducer = generateResponseContent(expectationFailed);
77                      responseTrigger.submitResponse(expectationFailed, responseContentProducer);
78                      return null;
79                  }
80              }
81          }
82          return chain.proceed(request, entityDetails, context, responseTrigger);
83      }
84  
85  }