org.apache.openjpa.kernel.exps
Class UnboundVariable

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

All Implemented Interfaces:

Serializable, Value

 class UnboundVariable
extends Val

Represents an unbound variable. When the query is evaluated, expressions containing unbound variables will be executed once for every element in the type's extent.

Author:

Abe White

Constructor Summary

UnboundVariable(Class type)
Constructor.

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.
boolean	isVariable() Return true if this value is a variable.
void	setImplicitType(Class type) Set the implicit type of the value, based on how it is used in the filter.
void	setValue(Object value) Set the variable's current value.

Methods inherited from class org.apache.openjpa.kernel.exps.Val

acceptVisit, eval, evaluate, evaluate, getAlias, getMetaData, getName, getPath, getSelectAs, isAggregate, isXPath, setAlias, setMetaData

Methods inherited from class java.lang.Object

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

Constructor Detail

UnboundVariable

public UnboundVariable(Class type)

Constructor. Provide variable name and type.

Method Detail

isVariable

public boolean isVariable()

Description copied from interface: Value

Return true if this value is a variable.

Specified by:

isVariable in interface Value

Overrides:

isVariable in class Val

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().

setValue

public void setValue(Object value)

Set the variable's current value. Expressions can be evaluated for every possible object in the extent of each unbound variable when looking for a match.

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