//装饰者超类 
public abstract class Beverage { 
    private String description = "unknown description"; 
     
    public String getDescription(){ 
        return description; 
    } 
   
    public abstract double cost(); 
} 


public abstract class Decorator extends Beverage{ 
 
    public abstract String getDescription(); 
} 

public class Coffee1 extends Beverage{ 
 
    @Override 
    public double cost() { 
        return 2.0;    //coffee1 价格2元 
    } 
 
    @Override 
    public String getDescription() { 
        return "coffee1"; 
    } 
} 
 
   
public class Coffee2 extends Beverage{ 
 
    @Override 
    public double cost() { 
        return 4.0;    //coffee2 价格4元 
    } 
 
    @Override 
    public String getDescription() { 
        return "coffee2"; 
    } 
} 

 
public class MilkDecorator extends Decorator { 
 
    private Beverage mBeverage; 
 
    public MilkDecorator(Beverage mBeverage) { 
        super(); 
        this.mBeverage = mBeverage; 
    } 
 
    @Override 
    public String getDescription() { 
        return mBeverage.getDescription() + " , milk"; 
    } 
 
    @Override 
    public double cost() { 
        return mBeverage.cost() + 1;   //加牛奶一元 
    } 
} 
 
 
public class SugarDecorator extends Decorator { 
 
    private Beverage mBeverage; 
 
    public SugarDecorator(Beverage mBeverage) { 
        super(); 
        this.mBeverage = mBeverage; 
    } 
 
    @Override 
    public String getDescription() { 
        return mBeverage.getDescription() + " , sugar"; 
    } 
 
    @Override 
    public double cost() { 
        return mBeverage.cost() + 2;   //加糖二元 
    } 
} 

 
public class Main { 
    public static void main(String[] args) { 
        System.out.println("要一份加糖的种类为coffee1的咖啡："); 
        Beverage beverage = new SugarDecorator(new Coffee1()); 
        System.out.println("种类 : " + beverage.getDescription() + "\n价格 : " 
                + beverage.cost()); 
 
        System.out.println("要一份加糖加两份牛奶的种类为coffee2的咖啡："); 
        beverage = new SugarDecorator(new MilkDecorator(new MilkDecorator( 
                new Coffee2()))); 
        System.out.println("种类 : " + beverage.getDescription() + "\n价格 : " 
                + beverage.cost()); 
    } 
}