绘图软件的开发，顾名思义，就是要开发一个能进行绘图的程序，为了能获取鼠标单击点的位置信息，需要用鼠标事件监听程序MouseListener和MouseMotionListener来获取鼠标事件，为此说明一个类来说明和实现这两个接口。还要调用调色板。-Drawing software development, by definition, is to develop a program capable of drawing, in order to obtain the location info