org.apache.openjpa.kernel.exps
Class UnaryMathVal

java.lang.Object
  org.apache.openjpa.kernel.exps.Val
      org.apache.openjpa.kernel.exps.UnaryMathVal

All Implemented Interfaces:

Serializable, Value

Direct Known Subclasses:

Abs, All, Any, Index, Size, Sqrt

abstract class UnaryMathVal
extends Val

Value produced by a mathematical operation on one value.

Author:

Abe White

Constructor Summary

UnaryMathVal(Val val)
Constructor.

Method Summary

void	acceptVisit(ExpressionVisitor visitor) Accept a visit from a tree visitor.
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.
protected abstract Class	getType(Class c) Return the type of this value based on the numeric type being operated on.
protected abstract Object	operate(Object o, Class c) Return the result of this mathematical operation on the given value.
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

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

UnaryMathVal

public UnaryMathVal(Val val)

Constructor. Provide the value to operate on.

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

getType

protected abstract Class getType(Class c)

Return the type of this value based on the numeric type being operated on.

operate

protected abstract Object operate(Object o,
                                  Class c)

Return the result of this mathematical operation on the given value.

acceptVisit

public void acceptVisit(ExpressionVisitor visitor)

Description copied from interface: Value

Accept a visit from a tree visitor.

Specified by:

acceptVisit in interface Value

Overrides:

acceptVisit in class Val