org.araneaframework.backend.list.memorybased.expression.compare
Class IsNullExpression

java.lang.Object
  org.araneaframework.backend.list.memorybased.expression.compare.IsNullExpression

All Implemented Interfaces:

CompositeExpression, Expression, Serializable

public class IsNullExpression

extends Object

implements CompositeExpression

See Also:

Serialized Form

Field Summary

protected Expression

expr

Constructor Summary

IsNullExpression(Expression expr)

Method Summary

Object	evaluate(VariableResolver resolver) Evaluates this Expression by returning its value.
Expression[]	getChildren()

Methods inherited from class java.lang.Object

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

Field Detail

expr

protected Expression expr

Constructor Detail

IsNullExpression

public IsNullExpression(Expression expr)

Method Detail

evaluate

public Object evaluate(VariableResolver resolver)
                throws ExpressionEvaluationException

Description copied from interface: Expression

Evaluates this Expression by returning its value. The returned value may also be null.

Specified by:

evaluate in interface Expression

Parameters:

resolver - Resolver that is used to evalute Variables.

Returns:

the value of this Expression.

Throws:

ExpressionEvaluationException - when the evaluating fails.

getChildren

public Expression[] getChildren()

Specified by:

getChildren in interface CompositeExpression