001 /**
002 * JDBM LICENSE v1.00
003 *
004 * Redistribution and use of this software and associated documentation
005 * ("Software"), with or without modification, are permitted provided
006 * that the following conditions are met:
007 *
008 * 1. Redistributions of source code must retain copyright
009 * statements and notices. Redistributions must also contain a
010 * copy of this document.
011 *
012 * 2. Redistributions in binary form must reproduce the
013 * above copyright notice, this list of conditions and the
014 * following disclaimer in the documentation and/or other
015 * materials provided with the distribution.
016 *
017 * 3. The name "JDBM" must not be used to endorse or promote
018 * products derived from this Software without prior written
019 * permission of Cees de Groot. For written permission,
020 * please contact cg@cdegroot.com.
021 *
022 * 4. Products derived from this Software may not be called "JDBM"
023 * nor may "JDBM" appear in their names without prior written
024 * permission of Cees de Groot.
025 *
026 * 5. Due credit should be given to the JDBM Project
027 * (http://jdbm.sourceforge.net/).
028 *
029 * THIS SOFTWARE IS PROVIDED BY THE JDBM PROJECT AND CONTRIBUTORS
030 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
031 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
032 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
033 * CEES DE GROOT OR ANY CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
034 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
035 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
036 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
037 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
038 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
039 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
040 * OF THE POSSIBILITY OF SUCH DAMAGE.
041 *
042 * Copyright 2001 (C) Alex Boisvert. All Rights Reserved.
043 * Contributions are Copyright (C) 2001 by their associated contributors.
044 *
045 */
046
047 package jdbm.helper;
048
049 import java.io.Serializable;
050 import java.util.Comparator;
051
052 /**
053 * Comparator for String objects. Delegates to String.compareTo().
054 *
055 * @author <a href="mailto:boisvert@intalio.com">Alex Boisvert</a>
056 * @version $Id: StringComparator.java,v 1.5 2005/06/25 23:12:31 doomdark Exp $
057 */
058 public final class StringComparator
059 implements Comparator, Serializable
060 {
061
062 /**
063 * Version id for serialization.
064 */
065 final static long serialVersionUID = 1L;
066
067
068 /**
069 * Compare two objects.
070 *
071 * @param obj1 First object
072 * @param obj2 Second object
073 * @return a positive integer if obj1 > obj2, 0 if obj1 == obj2,
074 * and a negative integer if obj1 < obj2
075 */
076 public int compare( Object obj1, Object obj2 )
077 {
078 if ( obj1 == null ) {
079 throw new IllegalArgumentException( "Argument 'obj1' is null" );
080 }
081
082 if ( obj2 == null ) {
083 throw new IllegalArgumentException( "Argument 'obj2' is null" );
084 }
085
086 return ( (String) obj1 ).compareTo((String) obj2 );
087 }
088
089 }