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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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8  * particular file as subject to the "Classpath" exception as provided
9  * by Oracle in the LICENSE file that accompanied this code.
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11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
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17  * You should have received a copy of the GNU General Public License version
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25 
26 /*
27  * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
28  * (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
29  *
30  * The original version of this source code and documentation
31  * is copyrighted and owned by Taligent, Inc., a wholly-owned
32  * subsidiary of IBM. These materials are provided under terms
33  * of a License Agreement between Taligent and Sun. This technology
34  * is protected by multiple US and International patents.
35  *
36  * This notice and attribution to Taligent may not be removed.
37  * Taligent is a registered trademark of Taligent, Inc.
38  *
39  */
40 
41 package sun.util.resources;
42 
43 import java.util.Enumeration;
44 import java.util.HashMap;
45 import java.util.Map;
46 import java.util.ResourceBundle;
47 import java.util.Set;
48 import sun.util.ResourceBundleEnumeration;
49 
50 /**
51  * Subclass of <code>ResourceBundle</code> which mimics
52  * <code>ListResourceBundle</code>, but provides more hooks
53  * for specialized subclass behavior. For general description,
54  * see {@link java.util.ListResourceBundle}.
55  * <p>
56  * This class leaves handleGetObject non-final, and
57  * adds a method createMap which allows subclasses to
58  * use specialized Map implementations.
59  */
60 public abstract class OpenListResourceBundle extends ResourceBundle {
61     /**
62      * Sole constructor.  (For invocation by subclass constructors, typically
63      * implicit.)
64      */
OpenListResourceBundle()65     protected OpenListResourceBundle() {
66     }
67 
68     // Implements java.util.ResourceBundle.handleGetObject; inherits javadoc specification.
handleGetObject(String key)69     public Object handleGetObject(String key) {
70         if (key == null) {
71             throw new NullPointerException();
72         }
73 
74         loadLookupTablesIfNecessary();
75         return lookup.get(key); // this class ignores locales
76     }
77 
78     /**
79      * Implementation of ResourceBundle.getKeys.
80      */
getKeys()81     public Enumeration<String> getKeys() {
82         ResourceBundle parent = this.parent;
83         return new ResourceBundleEnumeration(handleGetKeys(),
84                 (parent != null) ? parent.getKeys() : null);
85     }
86 
87     /**
88      * Returns a set of keys provided in this resource bundle
89      */
handleGetKeys()90     public Set<String> handleGetKeys() {
91         loadLookupTablesIfNecessary();
92 
93         return lookup.keySet();
94     }
95 
96     /**
97      * Returns the parent bundle
98      */
getParent()99     public OpenListResourceBundle getParent() {
100         return (OpenListResourceBundle)parent;
101     }
102 
103     /**
104      * See ListResourceBundle class description.
105      */
getContents()106     abstract protected Object[][] getContents();
107 
108     /**
109      * Load lookup tables if they haven't been loaded already.
110      */
loadLookupTablesIfNecessary()111     void loadLookupTablesIfNecessary() {
112         if (lookup == null) {
113             loadLookup();
114         }
115     }
116 
117     /**
118      * We lazily load the lookup hashtable.  This function does the
119      * loading.
120      */
loadLookup()121     private synchronized void loadLookup() {
122         if (lookup != null)
123             return;
124 
125         Object[][] contents = getContents();
126         Map temp = createMap(contents.length);
127         for (int i = 0; i < contents.length; ++i) {
128             // key must be non-null String, value must be non-null
129             String key = (String) contents[i][0];
130             Object value = contents[i][1];
131             if (key == null || value == null) {
132                 throw new NullPointerException();
133             }
134             temp.put(key, value);
135         }
136         lookup = temp;
137     }
138 
139     /**
140      * Lets subclasses provide specialized Map implementations.
141      * Default uses HashMap.
142      */
createMap(int size)143     protected Map createMap(int size) {
144         return new HashMap(size);
145     }
146 
147     private Map lookup = null;
148 }
149