001    // Copyright Apr 15, 2006 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    package org.apache.tapestry.asset;
015    
016    import java.util.Comparator;
017    
018    
019    /**
020     * Used to guarantee that whenever present, the PATH key entry 
021     * of an asset service link is always appended last in that path
022     * string. This is required for certain relative url operations. (ie dojo baseRelativePath)
023     * 
024     * @author jkuhnert
025     */
026    public class AssetComparator implements Comparator
027    {
028    
029        /** 
030         * {@inheritDoc}
031         */
032        public int compare(Object o1, Object o2)
033        {
034            if (!String.class.isInstance(o1) || !String.class.isInstance(o2))
035                return 1;
036            
037            String key1 = (String)o1;
038            String key2 = (String)o2;
039            
040            if (key1.toUpperCase().equals("PATH") && !key2.toUpperCase().equals("PATH"))
041                return 1;
042            else if (key2.toUpperCase().equals("PATH") && !key1.toUpperCase().equals("PATH"))
043                return -1;
044            else return key1.compareToIgnoreCase(key2);
045        }
046    
047    }