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/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Michael Powers
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/
package net.wotonomy.datastore;
import java.io.Serializable;
import java.util.Comparator;
import net.wotonomy.foundation.internal.ValueConverter;
/**
* DefaultComparator exists to compare basic java primitive wrappers, since
* these classes don't implement Comparable in jdk 1.1.x. Also uses
* ValueConverter to try to match types for comparison.
*/
public class DefaultComparator implements Comparator, Serializable {
public int compare(Object o1, Object o2) {
// System.out.println( "compare: " + o1 + " : " + o1.getClass() + " : " + o2 + " : " + o2.getClass() );
/*
* if ( ( o1 instanceof Comparable ) && ( o2 instanceof Comparable ) ) { return
* ((Comparable)o1).compareTo( o2 ); }
*/
if ((o1 instanceof Number) && (o2 instanceof Number)) {
// TODO: special case for each type would be faster
return (int) (((Number) o1).doubleValue() - ((Number) o2).doubleValue());
}
if (o1 instanceof StringBuffer) {
o1 = o1.toString();
}
if (o2 instanceof StringBuffer) {
o2 = o2.toString();
}
if ((o1 instanceof String) && (o2 instanceof String)) {
return ((String) o1).compareTo(((String) o2));
}
if ((o1 instanceof Character) && (o2 instanceof Character)) {
return (int) ((Character) o1).charValue() - ((Character) o2).charValue();
}
if ((o1 instanceof Byte) && (o2 instanceof Byte)) {
return (int) ((Byte) o1).byteValue() - ((Byte) o2).byteValue();
}
if ((o1 instanceof Boolean) && (o2 instanceof Boolean)) {
if (o1.equals(o2))
return 0;
// presumably TRUE is greater than FALSE
if (o1.equals(Boolean.TRUE))
return 1;
return -1;
}
// handle all NULL cases: NULL is less than anything else.
if ((o1 == null) && (o2 == null))
return 0;
if ((o1 == null) && (o2 != null))
return -1;
if ((o2 == null) && (o1 != null))
return 1;
if (o1.getClass() != o2.getClass()) {
Object convertedValue;
if (!(o2 instanceof String))
// (string should be lowest common demoninator, if possible)
{
// convert first to second's type
convertedValue = ValueConverter.convertObjectToClass(o1, o2.getClass());
if (convertedValue != null) {
return compare(convertedValue, o2);
}
}
// convert second to first's type
convertedValue = ValueConverter.convertObjectToClass(o2, o1.getClass());
if (convertedValue != null) {
return -1 * compare(convertedValue, o1); // reverse result
}
}
// we tried really hard, but these values are incomparable:
// we'll consider them equal.
return 0;
}
public boolean equals(Object obj) {
return (obj == this);
}
}
/*
* $Log$ Revision 1.2 2006/02/19 16:26:19 cgruber Move non-unit-test code to
* tests project Fix up code to work with proper imports Fix maven dependencies.
*
* Revision 1.1 2006/02/16 13:18:56 cgruber Check in all sources in
* eclipse-friendly maven-enabled packages.
*
* Revision 1.1.1.1 2000/12/21 15:47:08 mpowers Contributing wotonomy.
*
* Revision 1.3 2000/12/20 16:25:36 michael Added log to all files.
*
*
*/
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