上传文件至 'w5'

w5/ShapeTest.java

@@ -0,0 +1,34 @@
+class Shape {
+    public void draw(){
+        System.out.println("画一个形状");
+    }
+}
+
+class Circle extends Shape{
+    @Override
+    public void draw(){
+        System.out.println("画一个圆形");
+    }
+}
+
+class Rectangle extends Shape{
+    @Override
+    public void draw(){
+        System.out.println("画一个矩形");
+    }
+}
+
+public class ShapeTest{
+    public static void main(String[]args){
+        Shape s1 = new Circle();
+        Shape s2 = new Rectangle();
+
+        s1.draw();
+        s2.draw();
+
+        Shape[]shapes={new Circle(),new Rectangle(),new Circle()};//两个new Circle 是为了演示数组中可以有多个相同类型对象共存
+        for(Shape s:shapes){
+            s.draw();//每个对象调用自己的draw版本
+        }
+    }
+}

w5/USBTest.java

@@ -0,0 +1,49 @@
+interface USB {//规定usb的规范
+    void plugln();
+    void work(); 
+}
+
+class Mouse implements USB {//implement意思是遵守规范
+    @Override
+    public void plugln(){
+        System.out.println("鼠标已接入USB口");
+    }
+
+    @Override
+    public void work(){
+        System.out.println("鼠标：移动光标，点击左右键");
+    }
+}
+
+class Keyboard implements USB{
+    @Override
+    public void plugln(){
+        System.out.println("键盘已插入USB口");
+    }
+
+    @Override
+    public void work(){
+        System.out.println("键盘：可以打字输入");
+    }
+}
+
+class Conputer{
+    public void useUSB(USB usb){
+        System.out.println("电脑检测到新设备");
+        usb.plugln();
+        usb.work();
+        System.out.println();
+    }
+}
+
+public class USBTest {
+    public static void main(String[] args) {
+        Computer computer = new Conputer();
+
+        USB mouse=new Mouse();
+        USB keyborad=new Keyboard();
+        
+        computer.useUSB(mouse);
+        computer.useUSB(keyboard);
+    }
+}