001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one
003     *  or more contributor license agreements.  See the NOTICE file
004     *  distributed with this work for additional information
005     *  regarding copyright ownership.  The ASF licenses this file
006     *  to you under the Apache License, Version 2.0 (the
007     *  "License"); you may not use this file except in compliance
008     *  with the License.  You may obtain a copy of the License at
009     *  
010     *    http://www.apache.org/licenses/LICENSE-2.0
011     *  
012     *  Unless required by applicable law or agreed to in writing,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License. 
018     *  
019     */
020    package org.apache.directory.shared.ldap.util;
021    
022    
023    import java.util.Dictionary;
024    import java.util.Enumeration;
025    import java.util.prefs.Preferences;
026    import java.util.prefs.BackingStoreException;
027    
028    import org.apache.directory.shared.i18n.I18n;
029    
030    
031    /**
032     * A wrapper around Preferences to access it as a Dictionary.
033     * 
034     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
035     * @version $Rev: 919765 $
036     */
037    public class PreferencesDictionary extends Dictionary<String,String>
038    {
039        /** the underlying wrapped preferences object */
040        private final Preferences prefs;
041    
042    
043        // ------------------------------------------------------------------------
044        // C O N S T R U C T O R
045        // ------------------------------------------------------------------------
046    
047        public PreferencesDictionary(Preferences prefs)
048        {
049            this.prefs = prefs;
050        }
051    
052    
053        // ------------------------------------------------------------------------
054        // E X T R A M E T H O D S
055        // ------------------------------------------------------------------------
056    
057        /**
058         * Gets the Preferences used as the backing store for this Dictionary.
059         * 
060         * @return the underlying Preferences object
061         */
062        public Preferences getPreferences()
063        {
064            return prefs;
065        }
066    
067    
068        // ------------------------------------------------------------------------
069        // D I C T I O N A R Y M E T H O D S
070        // ------------------------------------------------------------------------
071    
072        public int size()
073        {
074            try
075            {
076                return prefs.keys().length;
077            }
078            catch ( BackingStoreException e )
079            {
080                throw new NestableRuntimeException( I18n.err( I18n.ERR_04423 ), e );
081            }
082        }
083    
084    
085        public boolean isEmpty()
086        {
087            try
088            {
089                return prefs.keys().length == 0;
090            }
091            catch ( BackingStoreException e )
092            {
093                throw new NestableRuntimeException( I18n.err( I18n.ERR_04423 ), e );
094            }
095        }
096    
097    
098        @SuppressWarnings("unchecked")
099        public Enumeration<String> elements()
100        {
101            try
102            {
103                return new ArrayEnumeration( prefs.keys() )
104                {
105                    public String nextElement()
106                    {
107                        String key = ( String ) super.nextElement();
108    
109                        return prefs.get( key, null );
110                    }
111                };
112            }
113            catch ( BackingStoreException e )
114            {
115                throw new NestableRuntimeException( I18n.err( I18n.ERR_04423 ), e );
116            }
117        }
118    
119    
120        @SuppressWarnings("unchecked")
121        public Enumeration<String> keys()
122        {
123            try
124            {
125                return new ArrayEnumeration( prefs.keys() );
126            }
127            catch ( BackingStoreException e )
128            {
129                throw new NestableRuntimeException( I18n.err( I18n.ERR_04423 ), e );
130            }
131        }
132    
133    
134        public String get( Object key )
135        {
136            if ( key instanceof String )
137            {
138                return prefs.get( ( String ) key, null );
139            }
140    
141            return prefs.get( key.toString(), null );
142        }
143    
144    
145        public String remove( Object key )
146        {
147            String retval = get( key );
148    
149            if ( key instanceof String )
150            {
151                prefs.remove( ( String ) key );
152            }
153            else
154            {
155                prefs.remove( key.toString() );
156            }
157    
158            return retval;
159        }
160    
161    
162        public String put( String key, String value )
163        {
164            String retval = get( key );
165    
166            prefs.put( key, value );
167    
168            return retval;
169        }
170    }