Java api + polygon self intersecting.

Question

Hi,
I am using this sdo_geom.validate_geometry_with_context to validate the polygon geometry.
Is there any equavalent oracle spatial java api to do similar validation (Oracle 10g), before loading the data. thanks.

Answer 1

Dear (What is your name?) User 810260,
Yes, there is the Java Topology Suite (1.12 is the latest).
Here is an example from its test harness:
public class IsValidTester {
  public IsValidTester() {
  public static void main(String[] args) throws Exception {
    WKTReader reader = new WKTReader(new GeometryFactory());
    Geometry g = reader.read("GEOMETRYCOLLECTION (POINT (110 300), POINT (100 110), POINT (130 210), POINT (150 210), POINT (150 180), POINT (130 170), POINT (140 190), POINT (130 200), LINESTRING (240 50, 210 120, 270 80, 250 140, 330 70, 300 160, 340 130, 340 130), POLYGON ((210 340, 220 260, 150 270, 230 220, 230 140, 270 210, 360 240, 260 250, 260 280, 240 270, 210 340), (230 270, 230 250, 200 250, 240 220, 240 190, 260 220, 290 230, 250 230, 230 270)))");
    IsValidOp op = new IsValidOp(g);
    if (!op.isValid()) {
      System.out.println(op.getValidationError().getMessage());
    else {
      System.out.println("OK");
}To create a JTS Geometry you can do something like this:
    public static void setPrecisionScale(int _numDecPlaces)
        precisionModelScale = _numDecPlaces < 0
                              ? (double)(1.0/Math.pow(10, Math.abs(_numDecPlaces)))
                              : (double)Math.pow(10, _numDecPlaces);
    public static String  myFunction(STRUCT _geom,
                                                int    _precision)   // _precision is decimal digits of precision NOT Oracle tolerance.
     throws SQLException
        try
            // Check geometry parameter
            if ( _geom == null )
                throw new SQLException("Supplied Sdo_Geometries is NULL.");
            // Get valid connection
            setConnection();
          int SRID = getSRID(_geom,0);  // My own function that gets the sdo_srid value from an SDO_Geometry STRUCT...
          PrecisionModel  pm              = new PrecisionModel(getPrecisionScale(_precision));   // <-- note use of getPrecisionScale method
          GeometryFactory geometryFactory = new GeometryFactory(pm,SRID);
          GeometryConverter     converter = new GeometryConverter(connection,geometryFactory);
          Geometry                    geo = converter.asGeometry(_geom);
          // Check converted geometries are valid
          if ( geo == null )
            throw new SQLException("SDO_Geometry conversion to JTS geometry returned NULL.");
          IsValidOp op = new IsValidOp(geo);
          if (!op.isValid()) {
             return op.getValidationError().getMessage();
        } catch(SQLException sqle) {
            System.err.println(sqle.getMessage());
            throw new SQLException(sqle.getMessage());
         return "TRUE";
    } If this helps you, please mark this post as the answer that got you the solution you wanted.
Simon