Centroid Class Reference

Returns the centroid of the given geometry. More...

Inheritance diagram for Centroid:

Collaboration diagram for Centroid:

Public Member Functions
String	getURI ()
Value	evaluate (ValueFactory valueFactory, Value... args) throws ValueExprEvaluationException

Protected Member Functions
Geometry	operation (Geometry geom)

Detailed Description

Returns the centroid of the given geometry.

Member Function Documentation

evaluate()

Value evaluate ( ValueFactory  valueFactory, Value...  args  ) throws ValueExprEvaluationException

inherited

References LiteralRegistry.getLiteral(), and GeometricUnaryFunction.operation().

                                                                                                            {
                if (args.length != 2) {
                        throw new ValueExprEvaluationException(getURI() + " requires exactly 2 arguments, got " + args.length);
                }
                
                LiteralType l=LiteralRegistry.getLiteral(((Literal)args[0]).getDatatype().toString());
                if(l instanceof VectorLiteral) {
                        Geometry geom=((VectorLiteral)l).read(args[0].stringValue());
                        Geometry result = operation(geom);
                        return valueFactory.createLiteral(((VectorLiteral) l).unparse(result),((Literal)args[0]).getDatatype());
                }
                throw new ValueExprEvaluationException("Argument given is not a geometry literal");
        }

getURI()

String getURI

(

)

References POSTGIS.ST_CENTROID.

                               {
                return POSTGIS.ST_CENTROID.stringValue();
        }

operation()

Geometry operation ( Geometry  geom )

protected

                                                    {
         Point centroid = geom.getCentroid();
         return centroid;
        }