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: */package jdbm.helper;
046:
047: import java.io.Serializable;
048: import java.util.Comparator;
049:
050: /**
051: * Comparator for Integer objects.
052: *
053: * @author <a href="mailto:cdaller@iicm.edu">Christof Dallermassl</a>
054: * @version $Id: IntegerComparator.java,v 1.2 2002/05/31 06:33:20 boisvert Exp $
055: */
056: public final class IntegerComparator implements Comparator,
057: Serializable {
058:
059: /**
060: * Version id for serialization.
061: */
062: final static long serialVersionUID = 1L;
063:
064: /**
065: * Compare two objects.
066: *
067: * @param obj1 First object
068: * @param obj2 Second object
069: * @return a positive integer if obj1 > obj2, 0 if obj1 == obj2,
070: * and a negative integer if obj1 < obj2
071: */
072: public int compare(Object obj1, Object obj2) {
073: if (obj1 == obj2) {
074: return 0;
075: }
076:
077: if (obj1 == null) {
078: throw new IllegalArgumentException(
079: "Argument 'obj1' is null");
080: }
081:
082: if (obj2 == null) {
083: throw new IllegalArgumentException(
084: "Argument 'obj2' is null");
085: }
086:
087: // complicated to avoid usage of Integer.compareTo, as this
088: // method is Java 1.2 only!
089: int int1 = ((Integer) obj1).intValue();
090: int int2 = ((Integer) obj2).intValue();
091: if (int1 == int2) {
092: return 0;
093: }
094:
095: if (int1 < int2) {
096: return -1;
097: } else {
098: return 1;
099: }
100: }
101:
102: }
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