例子

机器人原有功能：对话、唱歌、放音乐
继承：拖地、跳舞
装饰器：拖地、跳舞
角色：component、decorator、concreteComponent、concreteDecorator

interface Robot{
	void doSomething();
}
class FirstRobot implements Robot{
	public void doSomething(){
		System.out.println("唱歌");
	}
}
class DecoratortRobot implements Robot{
	private Robot robot;
	public DecoratortRobot(Robot robot){
		this.robot=robot;
	}
	public void doSomething(){
		System.out.println("唱歌");
	}
	public void doMoreThing(){
		root.doSomeThing();
		System.out.println("跳舞");
	}
}