设计模式之---外观模式

外观模式(Facade)，为子系统中的一组接口提供一个一致的界面，此模式定义了一个高层接口，这个接口使得这一子系统更加容易使用。

何时使用外观模式：



实例：



package facade;

public class SubSystemOne {
public void methodOne() {
System.out.println("方法一");
}
}

package facade;

public class SubSystemTwo {
public void methodTwo() {
System.out.println("方法二");
}
}

package facade;

public class SubSystemThree {
public void methodThree() {
System.out.println("方法三");
}
}

package facade;

public class Facade {

private SubSystemOne subSystemOne;
private SubSystemTwo subSystemTwo;
private SubSystemThree subSystemThree;

public void setSubSystemOne(SubSystemOne subSystemOne) {
this.subSystemOne = subSystemOne;
}
public void setSubSystemTwo(SubSystemTwo subSystemTwo) {
this.subSystemTwo = subSystemTwo;
}
public void setSubSystemThree(SubSystemThree subSystemThree) {
this.subSystemThree = subSystemThree;
}

public void methodA() {
subSystemOne.methodOne();
subSystemTwo.methodTwo();
}
public void methodB() {
subSystemThree.methodThree();
subSystemTwo.methodTwo();
}

}

package facade;

public class Client {

public static void main(String[] args) {
// TODO Auto-generated method stub
Facade facade=new Facade();
facade.setSubSystemOne(new SubSystemOne());
facade.setSubSystemTwo(new SubSystemTwo());
facade.setSubSystemThree(new SubSystemThree());
facade.methodA();
facade.methodB();
}

}