com.tensegrity.generic.util
Class MapReverse

java.lang.Object
  com.tensegrity.generic.util.MapReverse

public final class MapReverse

extends java.lang.Object

This class contains a method to reverse a map. The operation is only possible if all the values are distinct.

Version:

$Id: MapReverse.java,v 1.7 2003/09/12 13:47:20 AndreasEbbert Exp $

Author:

S. Rutz

Method Summary

static java.util.Map

reverse(java.util.Map map) Reverses a map.

Methods inherited from class java.lang.Object

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

Method Detail

reverse

public static final java.util.Map reverse(java.util.Map map)
                                   throws MapReverseNotPossibleException

Reverses a map. A new map is allocated and the keys of the new map are the values of the input map. The associated keys of the original values become the values of the reversed map.

Please note that reversing a map is only possible if all of the values are unique (and not just the keys). If the values are not unique, the method will throw an exception.

Parameters:

map - the Map to reverse; may not be null.

Returns:

the reversed map.

Throws:

MapReverseNotPossibleException, - if the values of the input map are not distinct.

InvalidArgumentException, - if argument is null.

MapReverseNotPossibleException