org.apache.jdo.impl.jdoql.scope
Class UNDEFINED

java.lang.Object
  extended byorg.apache.jdo.impl.jdoql.scope.UNDEFINED

public class UNDEFINED
extends java.lang.Object

An instance of this class represents an undefined value in a ValueTable (ParameterTable or VariableTable).

Author:
Michael Bouschen

Field Summary
private static UNDEFINED undefined
          The singleton UNDEFINED instance.
 
Constructor Summary
private UNDEFINED()
          Creates new UNDEFINED.
 
Method Summary
static UNDEFINED getInstance()
          Get an instance of UNDEFINED
 java.lang.String toString()
          Returns a string representation of an UNDEFINED instance.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

undefined

private static UNDEFINED undefined
The singleton UNDEFINED instance.

Constructor Detail

UNDEFINED

private UNDEFINED()
Creates new UNDEFINED. This constructor should not be called directly; instead, the singleton access method getInstance() should be used.

Method Detail

getInstance

public static UNDEFINED getInstance()
Get an instance of UNDEFINED

Returns:
an instance of UNDEFINED

toString

public java.lang.String toString()
Returns a string representation of an UNDEFINED instance.