1，创建顶级类
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html]
package com.pattern.decorate;
public abstract class Beverage {
String description = "Unknown Beverage";
public String getDescription(){
return description;
}
public abstract double cost();
}
2，创建产品类
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package com.pattern.decorate;
public class Espresso extends Beverage{
public Espresso(){
description = "Espresso";
}
/**
* @see com.pattern.decorate.Beverage#cost()
*/
@Override
public double cost() {
return 1.99;
}
}
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package com.pattern.decorate;
public class HouseBlend extends Beverage{
public HouseBlend(){
description = "House Blend Coffee";
}
/**
* @see com.pattern.decorate.Beverage#cost()
*/
@Override
public double cost() {
return .89;
}
}
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package com.pattern.decorate;
public class DarkRoast extends Beverage {
public DarkRoast(){
description = "DarkRoast";
}
/**
* @see com.pattern.decorate.Beverage#cost()
*/
@Override
public double cost() {
return 2.99;
}
}
3，创建装饰类
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package com.pattern.decorate;
public abstract class CondimentDecorator extends Beverage{
public abstract String getDescription();
}
4，创建装饰类的具体实现类
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package com.pattern.decorate;
public class Whip extends CondimentDecorator {
public Beverage beverage;
public Whip(Beverage beverage) {
this.beverage = beverage;
}
/**
* @see com.pattern.decorate.CondimentDecorator#getDescription()
*/
@Override
public String getDescription() {
return beverage.getDescription()+", Whip";
}
/**
* @see com.pattern.decorate.Beverage#cost()
*/
@Override
public double cost() {
return .30+beverage.cost();
}
}
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package com.pattern.decorate;
public class Mocha extends CondimentDecorator{
Beverage beverage;
public Mocha(Beverage beverage){
this.beverage = beverage;
}
/**
* @see com.pattern.decorate.CondimentDecorator#getDescription()
*/
@Override
public String getDescription() {
return beverage.getDescription()+", Mocha";
}
/**
* @see com.pattern.decorate.Beverage#cost()
*/
@Override
public double cost() {
return .20+beverage.cost();
}
}
5，测试
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package com.pattern.decorate;
public class StarbuzzCoffee {
public static void main(String[] args) {
Beverage beverage = new Espresso();
System.out.println(beverage.getDescription()+" $"+beverage.cost());
Beverage beverage2 = new DarkRoast();
beverage2 = new Mocha(beverage2);
beverage2 = new Mocha(beverage2);
beverage2 = new Whip(beverage2);
System.out.println(beverage2.getDescription()+