org.deegree.model.filterencoding
Class ArithmeticExpression

java.lang.Object
  org.deegree.model.filterencoding.Expression
      org.deegree.model.filterencoding.ArithmeticExpression

public class ArithmeticExpression
extends Expression

Encapsulates the information of a <Add> / <Sub>/ <Mul> or <DIV> element as defined in the Expression DTD.

Version:

$Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18 Jun 2009) $

Author:

Markus Schneider, last edited by: $Author: mschneider $

Field Summary

(package private) Expression	expr1 The first operand.
(package private) Expression	expr2 The second operand.

Fields inherited from class org.deegree.model.filterencoding.Expression

id

Constructor Summary

ArithmeticExpression(int id, Expression expr1, Expression expr2)
Constructs a new ArithmeticExpression.

Method Summary

static Expression	buildFromDOM(org.w3c.dom.Element element) Given a DOM-fragment, a corresponding Expression-object is built.
java.lang.Object	evaluate(Feature feature) Returns this ArithmeticExpression/tt>'s value (to be used in the evaluation of complex Expressions).
Expression	getFirstExpression() returns the first expression
Expression	getSecondExpression() returns the second expression
java.lang.StringBuffer	toXML() Produces an indented XML representation of this object.

Methods inherited from class org.deegree.model.filterencoding.Expression

getExpressionId, getExpressionName

Methods inherited from class java.lang.Object

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

Field Detail

expr1

Expression expr1

The first operand.

expr2

Expression expr2

The second operand.

Constructor Detail

ArithmeticExpression

public ArithmeticExpression(int id,
                            Expression expr1,
                            Expression expr2)

Constructs a new ArithmeticExpression.

Parameters:

id -

expr1 -

expr2 -

Method Detail

buildFromDOM

public static Expression buildFromDOM(org.w3c.dom.Element element)
                               throws FilterConstructionException

Given a DOM-fragment, a corresponding Expression-object is built. This method recursively calls other buildFromDOM () - methods to validate the structure of the DOM-fragment.

Parameters:

element -

Returns:

the new instance

Throws:

FilterConstructionException - if the structure of the DOM-fragment is invalid

toXML

public java.lang.StringBuffer toXML()

Produces an indented XML representation of this object.

Specified by:

toXML in class Expression

Returns:

XML representation of this object.

evaluate

public java.lang.Object evaluate(Feature feature)
                          throws FilterEvaluationException

Returns this ArithmeticExpression/tt>'s value (to be used in the evaluation of complex Expressions). TODO: Improve datatype handling.

Specified by:

evaluate in class Expression

Parameters:

feature - that determines the concrete values of PropertyNames in the expression

Returns:

the resulting value (as Double)

Throws:

FilterEvaluationException - if the expressions are not numerical

getFirstExpression

public Expression getFirstExpression()

returns the first expression

Returns:

the first expression

getSecondExpression

public Expression getSecondExpression()

returns the second expression

Returns:

the second expression