hand first 设计模式 -外观模式

外观模式:提供了一个统一的接口,用来访问子系统中的一群接口.外观定义了一个高层接口,让子系统更容易使用.

public class Light{
	
    private String name;
    
    public Light(String name){
    	this.name = name;
    }
	
	public void on(){
		System.out.println(name +" is on");
	}
	
	public void off(){
		System.out.println(name +" is off");
	}

}

public class TV {

	private String name;

	public TV(String name) {
		this.name = name;
	}

	public void off() {
		// TODO Auto-generated method stub
		System.out.println(name + " is off");

	}

	public void on() {
		// TODO Auto-generated method stub
		System.out.println(name + " is on");

	}

}

摇控器

public class Controler {

	private TV tv;
	private Light light;

	public Controler(TV tv, Light light) {
		this.tv = tv;
		this.light = light;
	}

	//看电视
	public void watchTv() {

		tv.on();
		light.off();

	}

	//关电视
	public void closeTv() {

		tv.off();
		light.on();

	}

}

测试类

public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
	   //利用外观模式	
            Controler control = new Controler(new TV("room tv"),new Light("room light"));
		
                  //用户根本不知道执行的细节
		control.watchTv();
		
		control.closeTv();
		

	}

}

最少知识原则

pulbic float getTemp(){
    return station.getThermometer().getTemperature();
}

上面的代码耦合了过多的对象(Station,Thermometer)

public float getTemp(){
   //将Temperature对象放在Station,
   return station.getTemperature();
}