小白学习设计模式之装饰者模式

装饰者模式:<br />1.动态的将新功能附加到对象上,在对象功能扩展方面,他比继承更具有弹性<br />2.一个基类,多个分支<br /><br />自我理解:<br />用人来举例,人有各个国家的人,这是一个分支,另一个分支就是穿着分支,冬季冷了添衣服就要添加衣服(这个黎姿不是特别合适)<br /><br />视频中的例子:<br />使用饮品来举例,coffer有各个品种的咖啡,选定主coffer还可以选定辅料,继续添加辅料,最后计算总价0<br />下面是我的代码例子,视频中的例子放在下一章

package com.wz.decorate;<br /><br />import java.math.BigDecimal;<br /><br />/**<br /> * people类,描述和计算人衣服总价<br /> *<br /> * @author Administrator<br /> * @create 2018-04-22 13:47<br /> */<br />public abstract class PeopleMain {<br /><br />    private String description;<br /><br />    private BigDecimal money = new BigDecimal(0);<br /><br />    public String getDescription() {<br />        return description;<br />    }<br /><br />    public BigDecimal getMoney() {<br />        return money;<br />    }<br /><br />    public void setDescription(String description) {<br />        this.description = description;<br />    }<br /><br />    public void setMoney(BigDecimal money) {<br />        this.money = money;<br />    }<br /><br />    public abstract BigDecimal cost();<br />}

package com.wz.decorate;<br /><br />import java.math.BigDecimal;<br /><br />/**<br /> * 国家人的分类<br /> *<br /> * @author Administrator<br /> * @create 2018-04-22 13:49<br /> */<br />public class People extends PeopleMain{<br /><br />    @Override<br />    public BigDecimal cost() {<br />        return super.getMoney();<br />    }<br />}

package com.wz.decorate;<br /><br />/**<br /> * 中国人<br /> *<br /> * @author Administrator<br /> * @create 2018-04-22 13:54<br /> */<br />public class China extends People {<br /><br />    public China() {<br />        super.setDescription("China");<br />    }<br />}

package com.wz.decorate;<br /><br />/**<br /> * 英国人<br /> *<br /> * @author Administrator<br /> * @create 2018-04-22 13:54<br /> */<br />public class Englisher extends People {<br /><br />    public Englisher() {<br />        super.setDescription("Englisher");<br />    }<br />}

package com.wz.decorate;<br /><br />import java.math.BigDecimal;<br /><br />/**<br /> * 衣服类<br /> *<br /> * @author Administrator<br /> * @create 2018-04-22 13:58<br /> */<br />public class Clothing extends PeopleMain {<br /><br />    private PeopleMain pm ;<br /><br />    public Clothing(PeopleMain pm) {<br />        this.pm = pm;<br />    }<br /><br />    @Override<br />    public String getDescription() {<br />        return super.getDescription() + "-" +pm.getDescription();<br />    }<br /><br />    @Override<br />    public BigDecimal cost() {<br />        return super.getMoney().add(pm.cost());<br />    }<br />}<br /><br />

package com.wz.decorate;<br /><br />import java.math.BigDecimal;<br /><br />/**<br /> * 裤子<br /> *<br /> * @author Administrator<br /> * @create 2018-04-22 14:08<br /> */<br />public class Pants extends Clothing {<br /><br />    public Pants(PeopleMain pm) {<br />        super(pm);<br />        super.setDescription("Pants");<br />        super.setMoney( new BigDecimal(150));<br />    }<br />}<br /><br />

package com.wz.decorate;<br /><br />import java.math.BigDecimal;<br /><br />/**<br /> * 鞋<br /> *<br /> * @author Administrator<br /> * @create 2018-04-22 14:06<br /> */<br />public class Shoe extends Clothing {<br /><br />    public Shoe(PeopleMain pm) {<br />        super(pm);<br />        super.setDescription("Show");<br />        super.setMoney(new BigDecimal(600));<br />    }<br />}

package com.wz.decorate;<br /><br />import java.math.BigDecimal;<br /><br />/**<br /> * 外套<br /> *<br /> * @author Administrator<br /> * @create 2018-04-22 14:03<br /> */<br />public class Outerwear extends Clothing {<br /><br />    public Outerwear(PeopleMain pm) {<br />        super(pm);<br />        super.setDescription("Outerwear");<br />        super.setMoney( new BigDecimal(300));<br />    }<br /><br /><br />}

package com.wz.decorate;<br /><br />/**<br /> * 测试类<br /> *<br /> * @author Administrator<br /> * @create 2018-04-22 14:10<br /> */<br />public class TestMain {<br /><br />    public static void main(String[] args) {<br />        PeopleMain pm ;<br />        pm = new Englisher();<br />        System.out.println(pm.getDescription());<br />        System.out.println(pm.cost());<br /><br />        System.out.println("==========================================");<br /><br />        pm = new China();<br />        pm = new Outerwear(pm);<br />        pm = new Pants(pm);<br />        pm = new Shoe(pm);<br />        System.out.println(pm.getDescription());<br />        System.out.println(pm.cost());<br /><br />    }<br />}