org.geotools.feature.visitor
Class MinVisitor

Object
  extended by 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
static class MinVisitor.MinResult
           
 
Constructor Summary
MinVisitor(Expression expr)
           
MinVisitor(int attributeTypeIndex, SimpleFeatureType type)
           
MinVisitor(String attributeTypeName)
           
MinVisitor(String attrName, SimpleFeatureType type)
           
 
Method Summary
 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.
 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

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
Throws:
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(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 -


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