001 /* ListResourceBundle -- a resource bundle build around a list
002 Copyright (C) 1998, 1999, 2001, 2002, 2005 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package java.util;
040
041 /**
042 * A <code>ListResouceBundle</code> provides an easy way, to create your own
043 * resource bundle. It is an abstract class that you can subclass. You should
044 * then overwrite the getContents method, that provides a key/value list.
045 *
046 * <p>The key/value list is a two dimensional list of Object. The first
047 * dimension ranges over the resources. The second dimension ranges from
048 * zero (key) to one (value). The keys must be of type String, and they are
049 * case-sensitive. For example:
050 *
051 <br><pre>public class MyResources
052 extends ListResourceBundle
053 {
054 public Object[][] getContents()
055 {
056 return contents;
057 }
058
059 static final Object[][] contents =
060 {
061 // LOCALIZED STRINGS
062 {"s1", "The disk \"{1}\" contains {0}."}, // MessageFormat pattern
063 {"s2", "1"}, // location of {0} in pattern
064 {"s3", "My Disk"}, // sample disk name
065 {"s4", "no files"}, // first ChoiceFormat choice
066 {"s5", "one file"}, // second ChoiceFormat choice
067 {"s6", "{0,number} files"} // third ChoiceFormat choice
068 {"s7", "3 Mar 96"}, // sample date
069 {"s8", new Dimension(1,5)} // real object, not just string
070 // END OF LOCALIZED MATERIAL
071 };
072 }</pre>
073 *
074 * @author Jochen Hoenicke
075 * @author Eric Blake (ebb9@email.byu.edu)
076 * @see Locale
077 * @see PropertyResourceBundle
078 * @since 1.1
079 * @status updated to 1.4
080 */
081 public abstract class ListResourceBundle extends ResourceBundle
082 {
083 /**
084 * The constructor. It does nothing special.
085 */
086 public ListResourceBundle()
087 {
088 }
089
090 /**
091 * Gets a resource for a given key. This is called by <code>getObject</code>.
092 *
093 * @param key the key of the resource
094 * @return the resource for the key, or null if it doesn't exist
095 */
096 public final Object handleGetObject(String key)
097 {
098 Object[][] contents = getContents();
099 int i = contents.length;
100 while (--i >= 0)
101 if (key.equals(contents[i][0]))
102 return contents[i][1];
103 return null;
104 }
105
106 /**
107 * This method should return all keys for which a resource exists.
108 *
109 * @return an enumeration of the keys
110 */
111 public Enumeration<String> getKeys()
112 {
113 // We make a new Set that holds all the keys, then return an enumeration
114 // for that. This prevents modifications from ruining the enumeration,
115 // as well as ignoring duplicates.
116 final Object[][] contents = getContents();
117 Set<String> s = new HashSet<String>();
118 int i = contents.length;
119 while (--i >= 0)
120 s.add((String) contents[i][0]);
121 ResourceBundle bundle = parent;
122 // Eliminate tail recursion.
123 while (bundle != null)
124 {
125 Enumeration<String> e = bundle.getKeys();
126 while (e.hasMoreElements())
127 s.add(e.nextElement());
128 bundle = bundle.parent;
129 }
130 return Collections.enumeration(s);
131 }
132
133 /**
134 * Gets the key/value list. You must override this method, and should not
135 * provide duplicate keys or null entries.
136 *
137 * @return a two dimensional list of String key / Object resouce pairs
138 */
139 protected abstract Object[][] getContents();
140 } // class ListResourceBundle