net.esper.eql.agg
Class AggregationSupport

java.lang.Object
  net.esper.eql.agg.AggregationSupport

All Implemented Interfaces:

AggregationMethod

public abstract class AggregationSupport
extends Object
implements AggregationMethod

Base class for use with plug-in aggregation functions.

Field Summary

protected String

functionName Provides the aggregation function name.

Constructor Summary

protected

AggregationSupport() Ctor.

Method Summary

String	getFunctionName() Returns the name of the aggregation function.
AggregationMethod	newAggregator(MethodResolutionService methodResolutionService) Make a new, initalized aggregation state.
void	setFunctionName(String functionName) Sets the aggregation function name.
abstract void	validate(Class childNodeType) Implemented by plug-in aggregation functions to allow such functions to validate the type of value passed to the function at statement compile time.

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.esper.eql.agg.AggregationMethod

enter, getValue, getValueType, leave

Field Detail

functionName

protected String functionName

Provides the aggregation function name.

Constructor Detail

AggregationSupport

protected AggregationSupport()

Ctor.

Method Detail

validate

public abstract void validate(Class childNodeType)

Implemented by plug-in aggregation functions to allow such functions to validate the type of value passed to the function at statement compile time.

Parameters:

childNodeType - is the class of result of the expression sub-node within the aggregation function, or null if a statement supplies no expression within the aggregation function

setFunctionName

public void setFunctionName(String functionName)

Sets the aggregation function name.

Parameters:

functionName - is the name of the aggregation function

getFunctionName

public String getFunctionName()

Returns the name of the aggregation function.

Returns:

aggregation function name

newAggregator

public AggregationMethod newAggregator(MethodResolutionService methodResolutionService)

Description copied from interface: AggregationMethod

Make a new, initalized aggregation state.

Specified by:

newAggregator in interface AggregationMethod

Parameters:

methodResolutionService - for use in creating new aggregation method instances as a factory

Returns:

initialized copy of the aggregator