org.apache.openjpa.kernel.exps
Class BoundVariable

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

All Implemented Interfaces:

Serializable, Value

 class BoundVariable
extends Val

Represents a bound variable. Variables are aliased to the collection that is stated to contain them in the query. When the query is evaluated, expressions containing variables will be executed once for every element in the collection.

Author:

Abe White

Constructor Summary

BoundVariable(Class type)
Constructor.

Method Summary

void	castTo(Class type) Cast this value to the given type.
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.
boolean	setValue(Object value) Set the value this variable should take for the current iteration.

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

BoundVariable

public BoundVariable(Class type)

Constructor. Provide variable name and type.

Method Detail

setValue

public boolean setValue(Object value)

Set the value this variable should take for the current iteration.

Returns:

false if the type is incompatible with the variable's declared type

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().

castTo

public void castTo(Class type)

Cast this value to the given type.

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