Package org.geotools.filter.expression

Class ExpressionAbstract

Object

ExpressionAbstract

All Implemented Interfaces:

Expression

Direct Known Subclasses:

DefaultExpression, FunctionImpl

public abstract class ExpressionAbstract
extends Object
implements Expression

Abstract superclass of these Expression implementations.

Author:

Jody Garnett

Field Summary

Fields inherited from interface Expression

NIL

Constructor Summary

Constructors

Constructor	Description
ExpressionAbstract()

Method Summary

Modifier and Type	Method	Description
Object	evaluate(Object object)	Subclass should override, default implementation returns null.
<T> T	evaluate(Object object, Class<T> context)	Default implementation delegates handling of context conversion to Converters utility class.

Methods inherited from class Object

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

Methods inherited from interface Expression

accept

Constructor Details

ExpressionAbstract

public ExpressionAbstract()

Method Details

evaluate

public Object evaluate(Object object)

Subclass should override, default implementation returns null.

Specified by:

evaluate in interface Expression

Returns:

default implementation returns null

evaluate

public <T> T evaluate(Object object,
 Class<T> context)

Default implementation delegates handling of context conversion to Converters utility class.

Subclasses are expected to make use of the Converters utility class (as the easiest way to provide value morphing in conformance with the Filter specification).

Specified by:

evaluate in interface Expression

Type Parameters:

T - The type of the returned object.

Parameters:

object - The object to evaluate the expression against.

context - The type of the resulting value of the expression.

Returns:

Evaluates the given expression based on the content of the given object an an instance of context.