code: public static Geometry scaleToUnitaryArea( Geometry polygon ) throws Exception {
          double area = polygon.getArea();
          double scale = sqrt(1.0 / area);
          AffineTransform scaleAT = new AffineTransform();
          scaleAT.scale(scale, scale);
          AffineTransform2D scaleTransform = new AffineTransform2D(scaleAT);
          polygon = JTS.transform(polygon, scaleTransform);
          return polygon;
      }
docs: Scales a {@link Polygon} to have an unitary area.
  
  @param polygon the geometry to scale.
  @return a copy of the scaled geometry.
  @throws Exception