动态地给一个对象添加一些额外的职责。就增加功能来说,Decorator模式相比生成子类更为灵活。
package com.lyz.design.decorator;
/**
* 定义Component接口Person
* @author binghe
*
*/
public interface Person {
void eat();
}
package com.lyz.design.decorator;
/**
* Person接口的实现类Man
* @author binghe
*
*/
public class Man implements Person {
public void eat() {
System.out.println("男人在吃");
}
}
package com.lyz.design.decorator;
/**
* Decorator抽象类实现Person接口
* @author binghe
*
*/
public abstract class Decorator implements Person {
protected Person person;
public void setPerson(Person person) {
this.person = person;
}
public void eat() {
person.eat();
}
}
package com.lyz.design.decorator;
/**
* Decorator的子类
* @author binghe
*
*/
public class ManDecoratorA extends Decorator {
public void eat() {
super.eat();
reEat();
System.out.println("ManDecoratorA类");
}
public void reEat() {
System.out.println("再吃一顿饭");
}
}
package com.lyz.design.decorator;
/**
* Decorator的子类
* @author binghe
*
*/
public class ManDecoratorB extends Decorator {
public void eat() {
super.eat();
System.out.println("===============");
System.out.println("ManDecoratorB类");
}
}
package com.lyz.design.decorator;
/**
* 测试类
* @author binghe
*
*/
public class Test {
public static void main(String[] args) {
Man man = new Man();
ManDecoratorA md1 = new ManDecoratorA();
ManDecoratorB md2 = new ManDecoratorB();
md1.setPerson(man);
md2.setPerson(md1);
md2.eat();
}
}
男人在吃
再吃一顿饭
ManDecoratorA类
===============
ManDecoratorB类