org.geotools.feature.visitor

Class MinVisitor

Object

MinVisitor

All Implemented Interfaces:

FeatureAttributeVisitor, FeatureCalc, FeatureVisitor

public class MinVisitor
extends Object
implements FeatureCalc, FeatureAttributeVisitor

Calculates the minimum value of an attribute.

Since:

2.2.M2

Author:

Cory Horner, Refractions

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MinVisitor.MinResult

Constructor Summary

Constructors

Constructor and Description
MinVisitor(Expression expr)
MinVisitor(int attributeTypeIndex, SimpleFeatureType type)
MinVisitor(String attributeTypeName)
MinVisitor(String attrName, SimpleFeatureType type)

Method Summary

Modifier and Type	Method and Description
Expression	getExpression()
List<Expression>	getExpressions() List of expressions used by visitor.
Comparable	getMin() Get the min value.
CalcResult	getResult() Returns the result of the calculation as a handy object which can be merged and modified.
Optional<List<Class>>	getResultType(List<Class> inputTypes) Returns the expected output type given the input type.
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 minimum.

Methods inherited from class Object

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

Constructor Detail

MinVisitor

public MinVisitor(String attributeTypeName)

MinVisitor

public MinVisitor(int attributeTypeIndex,
                  SimpleFeatureType type)
           throws IllegalFilterException

Throws:

IllegalFilterException

MinVisitor

public MinVisitor(String attrName,
                  SimpleFeatureType type)
           throws IllegalFilterException

Throws:

IllegalFilterException

MinVisitor

public MinVisitor(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

getResultType

public Optional<List<Class>> getResultType(List<Class> inputTypes)

Description copied from interface: FeatureAttributeVisitor

Returns the expected output type given the input type.

Specified by:

getResultType in interface FeatureAttributeVisitor

Parameters:

inputTypes - The type of the input expressions

visit

public void visit(SimpleFeature feature)

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

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

getMin

public Comparable getMin()

Get the min value.

Returns:

Minimum value

reset

public void reset()

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

getExpression

public Expression getExpression()

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 'min', the value stored is of type 'Comparable'.