/*
Copyright (c) 1999, 2000 Brown University, Providence, RI
All Rights Reserved
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose other than its incorporation into a
commercial product is hereby granted without fee, provided that the
above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation, and that the name of Brown University not be used in
advertising or publicity pertaining to distribution of the software
without specific, written prior permission.
BROWN UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR ANY PARTICULAR PURPOSE. IN NO EVENT SHALL BROWN
UNIVERSITY BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
package jdsl.core.ref;
/**
* Implements the JDSL HashComparator interface in terms of Java's
* native Object methods equals(.) and hashCode().
*
* @author Keith Schmidt (kas)
* @version JDSL 2.1.1
*/
public class ObjectHashComparator
implements jdsl.core.api.HashComparator {
/**
* @param o Object you propose to compare with this comparator
* @return Whether o is non-null
*/
public boolean isComparable (Object o) {
return (o != null);
}
/**
* returns x1.equals(x2)
*
* @param x1 the reference object in the comparison.
* @param x2 the object tested against the reference object.
* @return whether x1 is equal to x2
*/
public boolean isEqualTo (Object x1, Object x2)
throws ClassCastException {
return x1.equals(x2);
}
/**
* @param o Object for which you desire a hash value
* @return a non-negative integer hash value
*/
public int hashValue (Object o) {
// mask off top bit to ensure non-negativity
return (o.hashCode() & 0x7FFFFFFF);
}
}