设计模式——外观模式(代码基本参考自《大话设计模式》)

public class SubSystemOne {
	public void MethodOne() {
		System.out.println("子系统方法一");
	}
}
public class SubSystemTwo {
	public void MethodTwo(){
		System.out.println("子系统方法二");
	}
}
public class SubSystemThree {
	public void MethodThree(){
		System.out.println("子系统方法三");
	}
}

// 外观类
public class Facade {
	SubSystemOne one;
	SubSystemTwo two;
	SubSystemThree three;
	
	public Facade() {
		one = new SubSystemOne();
		two = new SubSystemTwo();
		three = new SubSystemThree();
	}
	
	public void methodA() {
		System.out.println("\n 方法组 A.....");
		one.MethodOne();
		two.MethodTwo();
		three.MethodThree();
	}
	
	public void methodB() {
		System.out.println("\n 方法组 B.....");
		two.MethodTwo();
		three.MethodThree();
	}
	
}

public class DemoEnter {
	public static void main(String[] args) {
		Facade facade = new Facade(); 
		facade.methodA(); // 由于 Facade 的作用，客户端可以根本不知道三个系统类的存在
		facade.methodB();
	}
}