Package org.geotools.filter.expression

Class InternalVolatileFunction

Object

ExpressionAbstract

FunctionImpl

InternalVolatileFunction

All Implemented Interfaces:

Expression, Function, InternalFunction, VolatileFunction

public abstract class InternalVolatileFunction
extends FunctionImpl
implements InternalFunction, VolatileFunction

A base class functions (i.e. anonymous inner classes) that are both volatile (i.e. explicitly stating evaluation needs to happen for each object in the collection being traversed) and internal (i.e. are not subject of SPI lookup, such as anonymous inner classes).

Since:

9.0

Field Summary

Fields inherited from class FunctionImpl

functionName

Fields inherited from interface Expression

NIL

Constructor Summary

Constructors

Constructor	Description
InternalVolatileFunction()
InternalVolatileFunction(String name)

Method Summary

Modifier and Type	Method	Description
InternalFunction	duplicate(Expression... parameters)	This default implementation just returns this if the number of expected parameters is zero, otherwise throws an IllegalArgumentException.
abstract Object	evaluate(Object object)	Default implementation simply returns the fallbackValue.

Methods inherited from class FunctionImpl

accept, dispatchArguments, equals, functionName, getFallbackValue, getFunctionName, getName, getParameters, getParameterValue, getParameterValue, hashCode, setFallbackValue, setName, setParameters, toString

Methods inherited from class ExpressionAbstract

evaluate

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface Expression

accept, evaluate

Methods inherited from interface Function

getFallbackValue, getFunctionName, getName, getParameters

Constructor Detail

InternalVolatileFunction

public InternalVolatileFunction()

InternalVolatileFunction

public InternalVolatileFunction(String name)

Method Detail

duplicate

public InternalFunction duplicate(Expression... parameters)

This default implementation just returns this if the number of expected parameters is zero, otherwise throws an IllegalArgumentException.

A subclass that do expect Expression parameters shall override this method and return a new instance of the same kind of InternalFunction configured to work against the given parameters.

Specified by:

duplicate in interface InternalFunction

Parameters:

parameters - the parameters the returned InternalFunction works on

Returns:

a new instance of the same kind of InternalFunction that works on the given parameters

See Also:

InternalFunction.duplicate(org.geotools.api.filter.expression.Expression[])

evaluate

public abstract Object evaluate(Object object)

Description copied from class: FunctionImpl

Default implementation simply returns the fallbackValue.

Please override this method to produce a value based on the provided arguments.

Specified by:

evaluate in interface Expression

Overrides:

evaluate in class FunctionImpl

Parameters:

object - Object being evaluated; often a Feature

Returns:

value for the provided object