自带测试类
源代码：

public class TestFan { public static void main(String[] args) { Fan o1=new Fan(); Fan o2=new Fan(); o1.setspeed(o1.FAST); o1.setradius(10); o1.setcolor("yellow"); o1.seton(true); o2.setspeed(o1.MEDIUM); o2.setradius(5); o2.setcolor("blue"); o2.seton(false); System.out.println(o1.toString()); System.out.println(o2.toString()); } }class Fan{int SLOW=1,MEDIUM=2,FAST=3;private int speed=SLOW;private boolean on=false;private double radius=5;String color="blue";public Fan(){}public void setspeed(int newspeed){speed=newspeed;}public void seton(boolean newon){on=newon;}public void setradius(double newradius){radius=newradius;}public void setcolor(String newcolor){color=newcolor;}public int getspeed(){return speed;}public boolean geton(){return on;}public double getradius(){return radius;}public String getcolor(){return color;}public String toString(){if(on){return speed+" "+color+" "+radius;}else{return "fan is off";}}}

运行结果：