上传文件至 'w5'

w5/Shape.java.java

@@ -0,0 +1,25 @@
+package w5;
+
+abstract class Shape{
+    public abstract void draw();   
+}
+class Circle extends Shape{
+    @Override
+    public void draw() {
+        System.out.println("画一个圆");
+    }
+}
+class Rectangle extends Shape{
+    @Override
+    public void draw() {
+        System.out.println("画一个矩形");
+    }
+}
+class ShapeTest{
+    public static void main(String[] args){
+        Shape circle = new Circle();
+        circle.draw();
+        Shape rectangle = new Rectangle();
+        rectangle.draw();
+    }
+}