org.zkoss.util

Class IdentityComparator<T>

java.lang.Object

org.zkoss.util.IdentityComparator<T>

All Implemented Interfaces:

java.util.Comparator<T>

public class IdentityComparator<T>
extends java.lang.Object
implements java.util.Comparator<T>

The comparator uses == and System.identifyHashCode to compare two objects. It assumes if o1 != o2, then c1 != c2 where c1 = System.identityHashCode(o1).

This is useful if dynamic proxy is used with TreeSet or TreeMap (so equals is expensive). Reason: the speed of identifyHashCode is much faster than dynamic proxy (150:1).

However, if possible, java.util.IdentityHashMap and IdentityHashSet are preferred.

Author:

tomyeh

See Also:

IdentityHashSet

Constructor Summary

Constructors

Constructor and Description
IdentityComparator()

Method Summary

Modifier and Type	Method and Description
int	compare(T o1, T o2)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

IdentityComparator

public IdentityComparator()

Method Detail

compare

public int compare(T o1,
                   T o2)

Specified by:

compare in interface java.util.Comparator<T>