001    /*--------------------------------------------------------------------------+
002    $Id: StringLengthComparator.java 26283 2010-02-18 11:18:57Z juergens $
003    |                                                                          |
004    | Copyright 2005-2010 Technische Universitaet Muenchen                     |
005    |                                                                          |
006    | Licensed under the Apache License, Version 2.0 (the "License");          |
007    | you may not use this file except in compliance with the License.         |
008    | 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, software      |
013    | distributed under the License is distributed on an "AS IS" BASIS,        |
014    | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
015    | See the License for the specific language governing permissions and      |
016    | limitations under the License.                                           |
017    +--------------------------------------------------------------------------*/
018    package edu.tum.cs.commons.collections;
019    
020    import java.util.Comparator;
021    
022    /**
023     * Compares strings by their length. Using this comparator on a list of string
024     * makes shorter strings appear first.
025     * 
026     * 
027     * @author Florian Deissenboeck
028     * @author $Author: juergens $
029     * @version $Rev: 26283 $
030     * @levd.rating GREEN Hash: BBB78877A0FFB47B3C9FB847CA3B4929
031     */
032    public class StringLengthComparator implements Comparator<String> {
033    
034        /**
035         * Compare strings by their length. Using this comparator on a list of
036         * string makes shorter strings appear first. {@inheritDoc}
037         */
038        public int compare(String string1, String string2) {
039            int length1;
040            int length2;
041    
042            if (string1 == null) {
043                length1 = 0;
044            } else {
045                length1 = string1.length();
046            }
047    
048            if (string2 == null) {
049                length2 = 0;
050            } else {
051                length2 = string2.length();
052            }
053    
054            return length1 - length2;
055        }
056    
057    }