public static GeometryCollection getHoles(Geometry geom) throws SQLException {
        if (geom != null) {
            if (geom.getDimension() >= 2) {
                ArrayList<Geometry> holes = new ArrayList<Geometry>();
                for (int i = 0; i < geom.getNumGeometries(); i++) {
                    Geometry subgeom = geom.getGeometryN(i);
                    if (subgeom instanceof Polygon) {
                        Polygon polygon = (Polygon) subgeom;
                        for (int j = 0; j < polygon.getNumInteriorRing(); j++) {
                            holes.add(GEOMETRY_FACTORY.createPolygon(
                                    GEOMETRY_FACTORY.createLinearRing(
                                            polygon.getInteriorRingN(j).getCoordinates()), null));
                        }
                    }
                }
                return GEOMETRY_FACTORY.createGeometryCollection(
                        holes.toArray(new Geometry[0]));
            } else {
                return GEOMETRY_FACTORY.createGeometryCollection(null);
            }
        }
        return null;
    }
public static GeometryCollection getHoles ( Geometry geom ) throws SQLException { if ( geom != null ) { if ( geom . getDimension ( ) >= 2 ) { ArrayList < Geometry > holes = new ArrayList < Geometry > ( ) ; for ( int i = 0 ; i < geom . getNumGeometries ( ) ; i ++ ) { Geometry subgeom = geom . getGeometryN ( i ) ; if ( subgeom instanceof Polygon ) { Polygon polygon = ( Polygon ) subgeom ; for ( int j = 0 ; j < polygon . getNumInteriorRing ( ) ; j ++ ) { holes . add ( GEOMETRY_FACTORY . createPolygon ( GEOMETRY_FACTORY . createLinearRing ( polygon . getInteriorRingN ( j ) . getCoordinates ( ) ) , null ) ) ; } } } return GEOMETRY_FACTORY . createGeometryCollection ( holes . toArray ( new Geometry [ 0 ] ) ) ; } else { return GEOMETRY_FACTORY . createGeometryCollection ( null ) ; } } return null ; }
Returns the given geometry's holes as a GeometryCollection.

@param geom Geometry
@return The geometry's holes
@throws SQLException