3．　　设计一个接口Shape，接口中包含方法：Draw和Resize。定义一些具体类，如：Point、Line、Circle、Rectangle等，每个类都实现接口Shape。Draw方法绘制图形，Resize方法改变图形大小。用Java实现这些接口和类，并用测试类测试它们。 注意：不需要真正绘制图形，如Line的Draw方法只需输出下面文本即可： “直线的起点是（x1,y1,），终点是（x2,y2）”-3. A Shape interface design, interfaces include : Draw and Resize. Some specific type definition, such as : Point, Line, Circle, Rectangle, each category are achieving Shape interface. Draw method of drawing, graphics Resize changed size. Using Java to achieve these interfaces and class, and use tests such testing. Note : no real drawing, such as the Draw Line method, only the following text can be output : "line is the starting point (x1, y1), and the ultimate goal is to (x2, y2)"