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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.commons.fileupload.util;
18  
19  import java.io.Serializable;
20  import java.util.ArrayList;
21  import java.util.Collections;
22  import java.util.Iterator;
23  import java.util.LinkedHashMap;
24  import java.util.List;
25  import java.util.Locale;
26  import java.util.Map;
27  
28  import org.apache.commons.fileupload.FileItemHeaders;
29  
30  /**
31   * Default implementation of the {@link FileItemHeaders} interface.
32   *
33   * @since 1.2.1
34   */
35  public class FileItemHeadersImpl implements FileItemHeaders, Serializable {
36  
37      /**
38       * Serial version UID, being used, if serialized.
39       */
40      private static final long serialVersionUID = -4455695752627032559L;
41  
42      /**
43       * Map of {@code String} keys to a {@code List} of
44       * {@code String} instances.
45       */
46      private final Map<String, List<String>> headerNameToValueListMap = new LinkedHashMap<>();
47  
48      /**
49       * Constructs a new instance.
50       */
51      public FileItemHeadersImpl() {
52          // empty
53      }
54  
55      /**
56       * Method to add header values to this instance.
57       *
58       * @param name name of this header
59       * @param value value of this header
60       */
61      public synchronized void addHeader(final String name, final String value) {
62          final String nameLower = name.toLowerCase(Locale.ROOT);
63          List<String> headerValueList = headerNameToValueListMap.get(nameLower);
64          if (null == headerValueList) {
65              headerValueList = new ArrayList<>();
66              headerNameToValueListMap.put(nameLower, headerValueList);
67          }
68          headerValueList.add(value);
69      }
70  
71      @Override
72      public String getHeader(final String name) {
73          final String nameLower = name.toLowerCase(Locale.ROOT);
74          final List<String> headerValueList = headerNameToValueListMap.get(nameLower);
75          if (null == headerValueList) {
76              return null;
77          }
78          return headerValueList.get(0);
79      }
80  
81      @Override
82      public Iterator<String> getHeaderNames() {
83          return headerNameToValueListMap.keySet().iterator();
84      }
85  
86      @Override
87      public Iterator<String> getHeaders(final String name) {
88          final String nameLower = name.toLowerCase(Locale.ROOT);
89          List<String> headerValueList = headerNameToValueListMap.get(nameLower);
90          if (null == headerValueList) {
91              headerValueList = Collections.emptyList();
92          }
93          return headerValueList.iterator();
94      }
95  
96  }