001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.util.io;
016    
017    import org.apache.tapestry.services.DataSqueezer;
018    
019    /**
020     * Squeezes a String (which is pretty simple, most of the time).
021     * 
022     * @author Howard Lewis Ship
023     */
024    
025    public class StringAdaptor implements SqueezeAdaptor
026    {
027        private static final String PREFIX = "S";
028    
029        public String getPrefix()
030        {
031            return PREFIX;
032        }
033    
034        public Class getDataClass()
035        {
036            return String.class;
037        }
038    
039        public String squeeze(DataSqueezer squeezer, Object data)
040        {
041            String string = (String) data;
042    
043            return PREFIX + string;
044        }
045    
046        /**
047         * Strips the prefix from the string. This method is only invoked by the
048         * {@link DataSqueezerImpl} if the string leads with its normal prefix (an 'S').
049         */
050    
051        public Object unsqueeze(DataSqueezer squeezer, String string)
052        {
053            if (string.length() == 1)
054                return "";
055    
056            return string.substring(1);
057        }
058    }