code: public static int getPointPositionAgainstLine( Coordinate point, Coordinate lineStart, Coordinate lineEnd ) {
          double value = (lineEnd.x - lineStart.x) * (point.y - lineStart.y) - (point.x - lineStart.x) * (lineEnd.y - lineStart.y);
          if (value > 0) {
              return 1;
          } else if (value < 0) {
              return -1;
          } else {
              return 0;
          }
      }
docs: Get the position of a point (left, right, on line) for a given line.
  
  @param point the point to check.
  @param lineStart the start coordinate of the line.
  @param lineEnd the end coordinate of the line.
  @return 1 if the point is left of the line, -1 if it is right, 0 if it is on the line.