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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.tika.detect;
18  
19  import java.io.IOException;
20  import java.io.InputStream;
21  import java.util.List;
22  
23  import org.apache.tika.metadata.Metadata;
24  import org.apache.tika.mime.MediaType;
25  
26  /**
27   * Content type detector that combines multiple different detection mechanisms.
28   */
29  public class CompositeDetector implements Detector {
30  
31      private final List<Detector> detectors;
32  
33      public CompositeDetector(List<Detector> detectors) {
34          this.detectors = detectors;
35      }
36  
37      public MediaType detect(InputStream input, Metadata metadata)
38              throws IOException { 
39          MediaType type = MediaType.OCTET_STREAM;
40          for (Detector detector : detectors) {
41              MediaType detected = detector.detect(input, metadata);
42              if (detected.isSpecializationOf(type)) {
43                  type = detected;
44              }
45          }
46          return type;
47      }
48  
49  }