org.springframework.util.comparator
Class InvertibleComparator

java.lang.Object
  org.springframework.util.comparator.InvertibleComparator

All Implemented Interfaces:

Serializable, Comparator

public class InvertibleComparator
extends Object
implements Comparator, Serializable

A decorator for a comparator, with an "ascending" flag denoting whether comparison results should be treated in forward (standard ascending) order or flipped for reverse (descending) order.

Since:

1.2.2

Author:

Keith Donald, Juergen Hoeller

See Also:

Serialized Form

Constructor Summary

InvertibleComparator(Comparator comparator)
Create an InvertibleComparator that sorts ascending by default.

InvertibleComparator(Comparator comparator, boolean ascending)
Create an InvertibleComparator that sorts based on the provided order.

Method Summary

int	compare(Object o1, Object o2)
boolean	equals(Object obj)
int	hashCode()
void	invertOrder() Invert the sort order: ascending -> descending or descending -> ascending.
boolean	isAscending() Return the sort order: ascending (true) or descending (false).
void	setAscending(boolean ascending) Specify the sort order: ascending (true) or descending (false).
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

InvertibleComparator

public InvertibleComparator(Comparator comparator)

Create an InvertibleComparator that sorts ascending by default. For the actual comparison, the specified Comparator will be used.

Parameters:

comparator - the comparator to decorate

InvertibleComparator

public InvertibleComparator(Comparator comparator,
                            boolean ascending)

Create an InvertibleComparator that sorts based on the provided order. For the actual comparison, the specified Comparator will be used.

Parameters:

comparator - the comparator to decorate

ascending - the sort order: ascending (true) or descending (false)

Method Detail

setAscending

public void setAscending(boolean ascending)

Specify the sort order: ascending (true) or descending (false).

isAscending

public boolean isAscending()

Return the sort order: ascending (true) or descending (false).

invertOrder

public void invertOrder()

Invert the sort order: ascending -> descending or descending -> ascending.

compare

public int compare(Object o1,
                   Object o2)

Specified by:

compare in interface Comparator

equals

public boolean equals(Object obj)

Specified by:

equals in interface Comparator

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object