说明：  本源码是一个applet，采用防抖动技术，用户在点击鼠标后便可以生成一个坐标，多次点击不清理屏幕，在按钮动作发生后便可以清理屏幕上已有的坐标。
(The source is an applet, using anti-shake technology, users can generate at the click of a mouse after a coordinate, multiple clicks do not clean the screen, the button can clean up after the action takes place already on the screen coordinates.)