org.apache.commons.collections.comparators
Class ReverseComparator

java.lang.Object
  |
  +--org.apache.commons.collections.comparators.ReverseComparator
All Implemented Interfaces:
Comparator, Serializable

public class ReverseComparator
extends Object
implements Comparator, Serializable

Reverses the order of another comparator by reversing the arguments to its compare method.

Since:
Commons Collections 2.0
Version:
$Revision: 1.17 $ $Date: 2004/01/14 21:43:18 $
Author:
Henri Yandell, Michael A. Smith
See Also:
Collections.reverseOrder(), Serialized Form

Constructor Summary
ReverseComparator()
          Creates a comparator that compares objects based on the inverse of their natural ordering.
ReverseComparator(Comparator comparator)
          Creates a comparator that inverts the comparison of the given comparator.
 
Method Summary
 int compare(Object o1, Object o2)
           
 boolean equals(Object that)
          Returns true iff that Object is is a Comparator whose ordering is known to be equivalent to mine.
 int hashCode()
          Implement a hash code for this comparator that is consistent with equals(java.lang.Object).
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ReverseComparator

public ReverseComparator()
Creates a comparator that compares objects based on the inverse of their natural ordering. Using this Constructor will create a ReverseComparator that is functionally identical to the Comparator returned by java.util.Collections.reverseOrder().
See Also:
Collections.reverseOrder()

ReverseComparator

public ReverseComparator(Comparator comparator)
Creates a comparator that inverts the comparison of the given comparator. If you pass in null, the ReverseComparator defaults to reversing the natural order, as per Collections.reverseOrder().
Parameters:
comparator - Comparator to reverse
Method Detail

compare

public int compare(Object o1,
                   Object o2)
Specified by:
compare in interface Comparator

hashCode

public int hashCode()
Implement a hash code for this comparator that is consistent with equals(java.lang.Object).
Overrides:
hashCode in class Object
Since:
Commons Collections 3.0

equals

public boolean equals(Object that)
Returns true iff that Object is is a Comparator whose ordering is known to be equivalent to mine.

This implementation returns true iff that.getClass() equals this.getClass(), and the underlying comparators are equal. Subclasses may want to override this behavior to remain consistent with the Comparator.equals(java.lang.Object) contract.

Specified by:
equals in interface Comparator
Overrides:
equals in class Object
Since:
Commons Collections 3.0


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