org.geotools.feature.visitor
Class MaxVisitor

Object
  MaxVisitor

All Implemented Interfaces:

FeatureAttributeVisitor, FeatureCalc, FeatureVisitor

public class MaxVisitor
extends Object
implements FeatureCalc, FeatureAttributeVisitor

Calculates the maximum value of an attribute.

Since:

2.2.M2

Author:

Cory Horner, Refractions Research Inc.

Nested Class Summary

static class

MaxVisitor.MaxResult

Constructor Summary

MaxVisitor(Expression expr)

MaxVisitor(int attributeTypeIndex, SimpleFeatureType type)

MaxVisitor(String attributeTypeName)

MaxVisitor(String attrName, SimpleFeatureType type)

Method Summary

Expression	getExpression()
List<Expression>	getExpressions() List of expressions used by visitor.
Comparable	getMax() Get the max value.
int	getNaNCount()
int	getNullCount()
CalcResult	getResult() Returns the result of the calculation as a handy object which can be merged and modified.
void	init(SimpleFeatureCollection collection)
void	reset()
void	setValue(Object result) Overwrites the result stored by the visitor.
void	visit(Feature feature) Visit the provided feature.
void	visit(SimpleFeature feature) Visitor function, which looks at each feature and finds the maximum.

Methods inherited from class Object

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

Constructor Detail

MaxVisitor

public MaxVisitor(String attributeTypeName)

MaxVisitor

public MaxVisitor(int attributeTypeIndex,
                  SimpleFeatureType type)
           throws IllegalFilterException

Throws:

IllegalFilterException

MaxVisitor

public MaxVisitor(String attrName,
                  SimpleFeatureType type)
           throws IllegalFilterException

Throws:

IllegalFilterException

MaxVisitor

public MaxVisitor(Expression expr)
           throws IllegalFilterException

Throws:

IllegalFilterException

Method Detail

init

public void init(SimpleFeatureCollection collection)

getExpressions

public List<Expression> getExpressions()

Description copied from interface: FeatureAttributeVisitor

List of expressions used by visitor.

Specified by:

getExpressions in interface FeatureAttributeVisitor

visit

public void visit(SimpleFeature feature)

Visitor function, which looks at each feature and finds the maximum.

Parameters:

feature - the feature to be visited

visit

public void visit(Feature feature)

Description copied from interface: FeatureVisitor

Visit the provided feature.

Please consult the documentation for the FeatureCollection you are visiting to learn more - the provided feature may be invalid, or read only.

Specified by:

visit in interface FeatureVisitor

getMax

public Comparable getMax()

Get the max value.

Returns:

Max value

Throws:

IllegalStateException - DOCUMENT ME!

getNaNCount

public int getNaNCount()

Returns:

the number of features which returned a NaN

getNullCount

public int getNullCount()

Returns:

the number of features which returned a null

reset

public void reset()

getExpression

public Expression getExpression()

getResult

public CalcResult getResult()

Description copied from interface: FeatureCalc

Returns the result of the calculation as a handy object which can be merged and modified.

Specified by:

getResult in interface FeatureCalc

Returns:

the results of the calculation

setValue

public void setValue(Object result)

Overwrites the result stored by the visitor. This should only be used by optimizations which will tell the visitor the answer rather than visiting all features.

For 'max', the value stored is of type 'Comparable'.

Parameters:

result -