Application: gvSIG desktop

{

    "name": "ST_Length",

    "group": "OGC",

    "template": "ST_Length({{geometry}})",

    "args": [

        "geometry - Geometry from which you have to calculate "

    ],

    "description": "Returns the 2D length of the geometry in units of spatial reference",

    "returnType": "Double",

    "sqlCompatible": true

}

import org.gvsig.expressionevaluator.impl.function.spatial.STLengthFunction;

        this.addFunction(new STLengthFunction());

package org.gvsig.expressionevaluator.impl.function.spatial;

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractGeometryFunction;

import org.gvsig.fmap.geom.Geometry;

public class STLengthFunction extends AbstractGeometryFunction {

    public STLengthFunction() {

        super("OGC", "ST_Length", Range.is(1));

    }

    @Override

    public boolean allowConstantFolding() {

        return true;

    }

    @Override

    public Object call(Interpreter interpreter, Object[] args) throws Exception {

        Geometry geom = getGeom(args, 0);

        double r = geom.perimeter();

        return r;

    }

}