[디자인 패턴] 2. 프록시 패턴

프록시 패턴 적용 전 코드

abstract class Animal {
    abstract String getName();
}
public class Mouse extends Animal {
    String name = "쥐";
    public String getName(){
        return name;
    }
}
public class Cat extends Animal {
    String name = "고양이";
    public String getName(){
        return name;
    }
}

//SRP -> Single Responsibility Principal
public class Doorman {
    public void 쫒아내(Animal animal){
				//DIP -> Dependency Inversion Principle
        System.out.println(animal.getName()+" 쫓아내");
    }
}
public class App {
    public static void main(String[] args) {
        Doorman doorman = new Doorman();
        Mouse mouse = new Mouse();
        Cat cat = new Cat();
        doorman.쫒아내(mouse);
        doorman.쫒아내(cat);

    }
}

프록시 패턴 적용 후 코드

abstract class Animal {
    abstract String getName();
}
public class Mouse extends Animal {
    String name = "쥐";
    public String getName(){
        return name;
    }
}
public class Cat extends Animal {
    String name = "고양이";
    public String getName(){
        return name;
    }
}
public class Doorman {
    public void 쫒아내(Animal animal){
        System.out.println(animal.getName()+" 쫓아내");
    }
}

public class DoormanProxy {

    private Doorman doorman;

    public DoormanProxy(Doorman doorman){
        this.doorman = doorman;
    }

    public void 쫒아내(Animal animal){
        hello();
        doorman.쫒아내(animal);
    }
    
    private void hello(){
        System.out.println("안녕");
    }
}
public class App {
    public static void main(String[] args) {

        Doorman doorman = new Doorman();
        DoormanProxy doormanProxy = new DoormanProxy(doorman);
        Mouse mouse = new Mouse();
        Cat cat = new Cat();

        doormanProxy.쫒아내(mouse);
        doormanProxy.쫒아내(cat);

    }
}