ComparisonMap


1   /******************************************************************************
2    * ComparisonMap.java
3    *****************************************************************************/
4   
5   /* J_LZ_COPYRIGHT_BEGIN *******************************************************
6   * Copyright 2001-2004 Laszlo Systems, Inc.  All Rights Reserved.              *
7   * Use is subject to license terms.                                            *
8   * J_LZ_COPYRIGHT_END *********************************************************/
9   
10  package org.openlaszlo.utils;
11  
12  import java.util.*;
13  
14  /**
15   * Hash table that stores keys case-sensitively, but compares them
16   * case-insensitively
17   *
18   * This differs from
19   * org.apache.commons.collections.map.CaseInsensitiveMap in that it
20   * preserves the first case used for a key (rather than converting all
21   * keys to lower case)
22   *
23   */
24  public class ComparisonMap extends HashMap {
25  
26      /** canonical lower-case map */
27      private HashMap keyMap;
28  
29      public Set normalizedKeySet() {
30          return keyMap.keySet();
31      }
32  
33      public ComparisonMap() {
34          super();
35          keyMap = new HashMap();
36      }
37  
38      public ComparisonMap(int initialCapacity) {
39          super(initialCapacity);
40          keyMap = new HashMap(initialCapacity);
41      }
42  
43      public ComparisonMap(int initialCapacity, float loadFactor) {
44          super(initialCapacity, loadFactor);
45          keyMap = new HashMap(initialCapacity, loadFactor);
46      }
47  
48      public ComparisonMap(Map m) {
49          this(m.size());
50          putAll(m);
51      }
52  
53      private Object   caseInsensitiveKey(Object   key) {
54          return key instanceof String   ? ((String  )key).toLowerCase() : key;
55      }
56  
57      public void clear() {
58          keyMap.clear();
59          super.clear();
60      }
61  
62      public Object   clone() {
63          return new ComparisonMap(this);
64      }
65  
66      public boolean containsKey(Object   key) {
67          return keyMap.containsKey(caseInsensitiveKey(key));
68      }
69  
70      /* containsValue just works */
71  
72      /* entrySet just works, keys have original case */
73  
74      public Object   get(Object   key) {
75          key = caseInsensitiveKey(key);
76          if (keyMap.containsKey(key)) {
77              return super.get(keyMap.get(key));
78          } else {
79              return null;
80          }
81      }
82  
83      /* isEmpty just works */
84  
85      /* keySet just works, keys have original case */
86  
87      public Object   put (Object   key, Object   value) {
88          keyMap.put(caseInsensitiveKey(key), key);
89          return super.put(key, value);
90      }
91  
92      public void putAll(Map m) {
93          for (Iterator i = m.entrySet().iterator(); i.hasNext(); ) {
94              Map.Entry entry = (Map.Entry) i.next();
95              put(entry.getKey(), entry.getValue());
96          }
97      }
98  
99      public Object   remove(Object   key) {
100         key = caseInsensitiveKey(key);
101         if (keyMap.containsKey(key)) {
102             return super.remove(keyMap.remove(key));
103         } else {
104             return null;
105         }
106     }
107 
108     /* size just works */
109 
110     /* values just works */
111 
112 }
113
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