Java装饰者模式（思维导图）

图1 装饰者模式【点击查看图片】

1，一个简单的以人为主体的装饰者模式

被装饰者

public interface Human {//被装饰者
    public void wearClothes();
    public void walkToWhere();
}

//定义被装饰者，被装饰者初始状态有些自己的装饰
class Person implements Human {

    @Override
    public void wearClothes() {
        // TODO Auto-generated method stub
        System.out.println("穿什么呢。。");
    }

    @Override
    public void walkToWhere() {
        // TODO Auto-generated method stub
        System.out.println("去哪里呢。。");
    }
}

装饰者

public abstract class Decorator implements Human {//定义装饰者
    private Human human;

    public Decorator(Human human) {//有参构造
        this.human = human;
    }

    @Override
    public void wearClothes() {
        human.wearClothes();
    }

    @Override
    public void walkToWhere() {
        human.walkToWhere();
    }
}


class Decorator_zero extends Decorator {

    public Decorator_zero(Human human) {
        super(human);
    }

    public void goHome() {
        System.out.println("进房子。。");
    }

    public void findMap() {
        System.out.println("书房找找Map。。");
    }

    @Override
    public void wearClothes() {
        // TODO Auto-generated method stub
        super.wearClothes();
        goHome();
    }

    @Override
    public void walkToWhere() {
        // TODO Auto-generated method stub
        super.walkToWhere();
        findMap();
    }
}


class Decorator_first extends Decorator {

    public Decorator_first(Human human) {
        super(human);
    }

    public void goClothespress() {
        System.out.println("去衣柜找找看。。");
    }

    public void findPlaceOnMap() {
        System.out.println("在Map上找找。。");
    }

    @Override
    public void wearClothes() {
        // TODO Auto-generated method stub
        super.wearClothes();
        goClothespress();
    }

    @Override
    public void walkToWhere() {
        // TODO Auto-generated method stub
        super.walkToWhere();
        findPlaceOnMap();
    }
}

class Decorator_two extends Decorator {

    public Decorator_two(Human human) {
        super(human);
    }

    public void findClothes() {
        System.out.println("找到一件D&G。。");
    }

    public void findTheTarget() {
        System.out.println("在Map上找到神秘花园和城堡。。");
    }

    @Override
    public void wearClothes() {
        // TODO Auto-generated method stub
        super.wearClothes();
        findClothes();
    }

    @Override
    public void walkToWhere() {
        // TODO Auto-generated method stub
        super.walkToWhere();
        findTheTarget();
    }
}

测试验证

public class Client {
    public static void main(String[] args) {
        Human person = new Person();
        Decorator decorator = new Decorator_two(new Decorator_first(new Decorator_zero(person)));

        decorator.wearClothes();
        decorator.walkToWhere();
    }
}

2，一个以汉堡添为主体的装饰者模式

被装饰者

public abstract class Humburger {//被装饰者，主体，被修补的物件
    protected  String name ;
    public String getName(){
        return name;
    }
    public abstract double getPrice();

}

class ChickenBurger extends Humburger {//被修饰者的原始状态
    public ChickenBurger(){
        name = "鸡腿堡";
    }
    @Override
    public double getPrice() {
        return 10;
    }
}

装饰者

public abstract class Condiment extends Humburger {//装饰者【修修补补的材料】
    public abstract String getName();
}

class Lettuce extends Condiment {
    Humburger humburger;
    public Lettuce(Humburger humburger){
        this.humburger = humburger;
    }
    @Override
    public String getName() {
        return humburger.getName()+" 加生菜";
    }
    @Override
    public double getPrice() {
        return humburger.getPrice()+1.5;
    }
}


class Chilli extends Condiment {
    Humburger humburger;
    public Chilli(Humburger humburger){
        this.humburger = humburger;
    }
    @Override
    public String getName() {
        return humburger.getName()+" 加辣椒";
    }
    @Override
    public double getPrice() {
        return humburger.getPrice();  //辣椒是免费的哦
    }

}

测试验证

public class Client {
    public static void main(String[] args) {
        Humburger humburger = new ChickenBurger();//鸡腿堡  价钱：10.0
        System.out.println(humburger.getName()+"  价钱："+humburger.getPrice());

        Lettuce lettuce = new Lettuce(humburger);//鸡腿堡 加生菜  价钱：11.5
        System.out.println(lettuce.getName()+"  价钱："+lettuce.getPrice());

        Chilli chilli = new Chilli(humburger);//鸡腿堡 加辣椒  价钱：10.0
        System.out.println(chilli.getName()+"  价钱："+chilli.getPrice());

        Chilli chilli2 = new Chilli(lettuce);//鸡腿堡 加生菜 加辣椒  价钱：11.5
        System.out.println(chilli2.getName()+"  价钱："+chilli2.getPrice());
    }

}

参考：https://blog.csdn.net/jason0539/article/details/22713711