org.apache.openjpa.kernel.exps
Class Count

java.lang.Object
  extended by org.apache.openjpa.kernel.exps.Val
      extended by org.apache.openjpa.kernel.exps.AggregateVal
          extended by 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


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