java 判断点是否在一条线段上

= new Scanner(System.in); Point point1 = new Point(); Point point2 = new Point(); double x, y; point1.setLocation(5.0, 5.0); point2.setLocation(1.0, 1.0); System.out.println("请分别输入点x,y的坐标："); x = scan.nextDouble(); y = scan.nextDouble(); boolean pdline = (x - point1.getX()) * (point1.getY() - point2.getY()) == (point1.getX() - point2.getX()) * (y - point1.getY()); if (pdline) { System.out.println("您输入的点在该条直线上"); } else { System.out.println("您输入的点不在该条直线上"); } scan.close(); }