code: public static Polygon removeCoordinates(Polygon poly) {
          Coordinate[] shellCoords = CoordinateUtils.removeDuplicatedCoordinates(poly.getExteriorRing().getCoordinates(),true);
          LinearRing shell = FACTORY.createLinearRing(shellCoords);
          ArrayList<LinearRing> holes = new ArrayList<LinearRing>();
          for (int i = 0; i < poly.getNumInteriorRing(); i++) {
              Coordinate[] holeCoords = CoordinateUtils.removeDuplicatedCoordinates(poly.getInteriorRingN(i).getCoordinates(),true);
              holes.add(FACTORY.createLinearRing(holeCoords));
          }
          return FACTORY.createPolygon(shell, GeometryFactory.toLinearRingArray(holes));
      }
docs: Removes duplicated coordinates within a Polygon.
  
  @param poly
  @return