org.apache.openjpa.kernel.exps
Class Count

java.lang.Object
  org.apache.openjpa.kernel.exps.Val
      org.apache.openjpa.kernel.exps.AggregateVal
          org.apache.openjpa.kernel.exps.Count

All Implemented Interfaces:

Serializable, Value

 class Count
extends AggregateVal

Count non-null values.

Author:

Abe White

Constructor Summary

Count(Val val)
Constructor.

Method Summary

protected Class	getType(Class c) Return the type of this aggregate based on the value type.
protected Object	operate(Collection os, Class c) Aggregate the given values.

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

acceptVisit, eval, eval, getType, isAggregate, setImplicitType

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

evaluate, evaluate, getAlias, getMetaData, getName, getPath, getSelectAs, isVariable, isXPath, setAlias, setMetaData

Methods inherited from class java.lang.Object

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

Constructor Detail

Count

public Count(Val val)

Constructor. Provide the value to count.

Method Detail

getType

protected Class getType(Class c)

Description copied from class: AggregateVal

Return the type of this aggregate based on the value type.

Specified by:

getType in class AggregateVal

operate

protected Object operate(Collection os,
                         Class c)

Description copied from class: AggregateVal

Aggregate the given values.

Specified by:

operate in class AggregateVal