org.apache.openjpa.kernel.exps
Class Null

java.lang.Object
  extended by org.apache.openjpa.kernel.exps.Val
      extended by org.apache.openjpa.kernel.exps.Null
All Implemented Interfaces:
Serializable, Value

 class Null
extends Val

Represents the null constant.

Author:
Abe White

Constructor Summary
Null()
           
 
Method Summary
protected  Object eval(Object candidate, Object orig, StoreContext ctx, Object[] params)
          Return this value for the given candidate.
 Class getType()
          Return the expected type for this value, or Object if the type is unknown.
 void setImplicitType(Class type)
          Set the implicit type of the value, based on how it is used in the filter.
 
Methods inherited from class org.apache.openjpa.kernel.exps.Val
acceptVisit, eval, evaluate, evaluate, getAlias, getMetaData, getName, getPath, getSelectAs, isAggregate, isVariable, isXPath, setAlias, setMetaData
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Null

Null()
Method Detail

getType

public Class getType()
Description copied from interface: Value
Return the expected type for this value, or Object if the type is unknown.


setImplicitType

public void setImplicitType(Class type)
Description copied from interface: Value
Set the implicit type of the value, based on how it is used in the filter. This method is only called on values who return Object from Value.getType().


eval

protected Object eval(Object candidate,
                      Object orig,
                      StoreContext ctx,
                      Object[] params)
Description copied from class: Val
Return this value for the given candidate.

Specified by:
eval in class Val


Copyright © 2006-2011 Apache Software Foundation. All Rights Reserved.