org.geotools.feature.visitor
Class MinVisitor

java.lang.Object
  org.geotools.feature.visitor.MinVisitor

All Implemented Interfaces:

FeatureCalc, FeatureVisitor

public class MinVisitor

extends java.lang.Object

implements FeatureCalc

Calculates the minimum value of an attribute.

Since:

2.2.M2

Author:

Cory Horner, Refractions

Nested Class Summary

static class

MinVisitor.MinResult

Constructor Summary

MinVisitor(Expression expr)

MinVisitor(int attributeTypeIndex, FeatureType type)

MinVisitor(java.lang.String attrName, FeatureType type)

Method Summary

Expression	getExpression()
java.lang.Comparable	getMin() Get the min value.
CalcResult	getResult() Returns the result of the calculation as a handy object which can be merged and modified.
void	reset()
void	setValue(java.lang.Object result) Overwrites the result stored by the visitor.
void	visit(Feature feature) Visitor function, which looks at each feature and finds the minimum.

Methods inherited from class java.lang.Object

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

Constructor Detail

MinVisitor

public MinVisitor(int attributeTypeIndex,
                  FeatureType type)
           throws IllegalFilterException

MinVisitor

public MinVisitor(java.lang.String attrName,
                  FeatureType type)
           throws IllegalFilterException

MinVisitor

public MinVisitor(Expression expr)
           throws IllegalFilterException

Method Detail

visit

public void visit(Feature feature)

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

Specified by:

visit in interface FeatureVisitor

Parameters:

feature - the feature to be visited

getMin

public java.lang.Comparable getMin()

Get the min value.

Returns:

Minimum value

Throws:

java.lang.IllegalStateException - DOCUMENT ME!

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(java.lang.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'.

Parameters:

result -