本程序实现用Java来进行画图，画图时可以进行图形的拖动，也可以画任意图形，也可以对图形进行旋转-The procedure to be implemented by the Java drawing, drawing and graphic can be dragged, it can draw any graphics, can also rotate graphics

java画板，模拟windows画板，程序存在一些问题，但基本能用-oh，my god