【设计模式】第十一篇 - 装饰模式 - 孙悟空的六神装
发布于: 2021 年 11 月 05 日
一，前言
7种结构型设计模式:桥接模式,适配器模式,装饰模式,组合模式,享元模式,外观模式,代理模式
上篇我们说了外观模式:提供一个统一接口来访问子系统中的一群接口外观定义了一个高层接口,让子系统更容易使用
开发中我们为一个对象添加新行为通常会采用继承的方式但通常这样做会导致子类泛滥的结果也就是我们常说的类爆炸,为后续的维护带来不便本着"开放-关闭"的设计原则,我们希望在不修改原有代码的情况下,为对象赋予新的职责
这篇的结构型设计模式就可以做到,它就是装饰模式,也叫做装饰器或装饰者模式复制代码
二，装饰模式简介
1，简介：
装饰者模式:动态地将责任附加到对象上,在不修改任何底层代码的情况下,为对象赋予新的职责
2，装饰模式类图：
从类图中我们可以看到: 装饰者和被装饰者(组件)拥有相同的接口,所以装饰者能够取代被装饰者 装饰者与组件进行组合时,通过对象组合为组件加入新的行为 所以装饰者模式能在不创建更多子类的情况下，实现对象功能的拓展
这也正是组合的威力所在,多用组合少用继承 如果依赖继承,类的行为只能在编译时静态决定,行为来自超类或子类进行覆盖 组合可以把装饰器和组件进行混合,而且是在运行时才决定具体行为复制代码
3，装饰模式中的角色：
抽象组件(Component)角色：给出一个抽象接口，规范准备接收附加责任的对象。具体组件(ConcreteComponent)角色：定义一个将要接收附加责任的类。
装饰(Decorator)角色：持有一个组件对象(Component)的实例，并定义一个与抽象构件接口一致的接口。具体装饰(ConcreteDecorator)角色：负责为组件对象赋予新职责。复制代码
三，装饰模式场景
我们选取一个比较适合装饰模式的场景来对这个模式进行学习最后我选择了游戏中为角色添加装备来获得属性加成的例子那么这篇的主题又回到了大家感兴趣的游戏话题上我们就来看看"王者荣耀"中孙悟空这个英雄的六神装
ps:这里对英雄和装备属性做了修改,和真实游戏中的属性不一致,望谅解!复制代码
我们的场景是这样的: 1,创建一个抽象组件Hero(即抽象组件角色),通过继承此类创建具体英雄,此类定义了英雄属性 2,通过继承Hero类创建具体英雄(孙悟空),并针对英雄个性化做属性调整 3,创建一个抽象装备类Equipment(即抽象装饰角色),继承自组件Hero,通过继承此类创建具体装备,此类需定义装饰新功能的接口,以重写为新的功能供外部调用 4,通过继承Equipment类创建具体装备类,此类需持有一个具体英雄(Hero)的引用,重写接口时对此引用信息做修改,以实现功能的变更和添加 5,使用4的方式创建6件装备,并逐一为英雄装饰,打印日志查看装饰后的英雄属性复制代码
四，装饰模式例子
1，创建抽象组件 Hero，即抽象组件角色，定义英雄属性：
package com.brave.decorator.pesticide.hero;
/** * 抽象英雄 * -每个具体英雄都继承自此类 * -默认属性数值均为100暴击率0%暴击效果2倍 * * @author Brave * */public abstract class Hero {
private String name = ""; // 名称 private double HP = 100; // 生命值 private double MP = 100; // 魔法值 private double ATK = 100; // 攻击力 private double DEF = 100; // 防御力 private double CRT = 0; // 暴击率加成 private double CRTE = 2; // 暴击效果 private double MS = 0; // 移动速度加成 private double AB = 0; // 破甲加成 private String equipment = ""; // 装备
public String getName() { return name; }
public void setName(String name) { this.name = name; }
public double getHP() { return HP; }
public void setHP(double hP) { HP = hP; }
public double getMP() { return MP; }
public void setMP(double mP) { MP = mP; }
public double getATK() { return ATK; }
public void setATK(double aTK) { ATK = aTK; }
public double getDEF() { return DEF; }
public void setDEF(double dEF) { DEF = dEF; }
public double getCRT() { return CRT; }
public void setCRT(double cRT) { CRT = cRT; }
public double getCRTE() { return CRTE; }
public void setCRTE(double cRTE) { CRTE = cRTE; }
public double getMS() { return MS; }
public void setMS(double mS) { MS = mS; }
public String getEquipment() { return equipment; }
public void setEquipment(String equipment) { this.equipment = equipment; }
public double getAB() { return AB; }
public void setAB(double aB) { AB = aB; }
public void printHeroAttr() { System.out.println("name = " + name); System.out.println("生命值:HP = " + HP); System.out.println("魔法值:MP = " + MP); System.out.println("攻击力:ATK = " + ATK); System.out.println("防御力:DEF = " + DEF); System.out.println("暴击率加成:CRT = " + CRT); System.out.println("暴击效果:CRTE = " + CRTE); System.out.println("移动速度加成:MS = " + MS); if(!equipment.equals(""))System.out.println("装备:equipment = " + equipment); }
}复制代码
2，通过继承 Hero 类创建具体英雄孙悟空，针对英雄个性化做属性调整
package com.brave.decorator.pesticide.hero;
/** * 具体英雄-孙悟空 * 初始暴击率为20%,暴击伤害150%; * * @author Brave * */public class MonkeyKing extends Hero {
public MonkeyKing() { setName("孙悟空"); setCRT(0.2); setCRTE(1.5); }
}复制代码
3，继承自组件 Hero，创建抽象装备类 Equipment，定义装饰新功能的接口，以重写为新的功能供外部调用
package com.brave.decorator.pesticide.equipment;
import com.brave.decorator.pesticide.hero.Hero;
/** * 抽象装备 * -每个具体装备都继承自此类 * * @author Brave * */public abstract class Equipment extends Hero{
// 强制重写-装备名称 public abstract String getName();
// 输出准备此件装备后的所有装备信息 public abstract double getHP(); public abstract double getMP(); public abstract double getATK(); public abstract double getDEF(); public abstract double getCRT(); public abstract double getCRTE(); public abstract double getMS(); public abstract double getAB(); public abstract String getEquipment();
// 强制重写-输出装备此件装备后的全部属性 public abstract void printHeroAttr();
}复制代码
4，通过继承 Equipment 类创建具体装备类
此类持有一个具体英雄(Hero)的引用，重写接口时对此引用信息做修改，以实现功能的变更和添加
创建6件装备: 鞋子:100移速 无尽之刃:50%暴击+50%暴击效果 破甲弓:100攻击+100破甲 冰痕之握:100防御+100魔法 装饰泣血之刃:100攻击+100生命 破军:200攻击复制代码
1）鞋子：增加 100 点移动速度
package com.brave.decorator.pesticide.equipment;
import com.brave.decorator.pesticide.hero.Hero;
/** * 鞋子:增加100点移动速度 * @author Brave * */public class Shoes extends Equipment {
private Hero hero;
public Shoes(Hero hero) { this.hero = hero; }
@Override public void printHeroAttr() { System.out.println("name = " + getName()); System.out.println("生命值:HP = " + getHP()); System.out.println("魔法值:MP = " + getMP()); System.out.println("攻击力:ATK = " + getATK()); System.out.println("防御力:DEF = " + getDEF()); System.out.println("暴击率加成:CRT = " + getCRT()); System.out.println("暴击效果:CRTE = " + getCRTE()); System.out.println("移动速度加成:MS = " + getMS()); System.out.println("破甲加成:AB = " + getAB()); System.out.println(getEquipment().equals("") ? "" : "装备:equipment = " + getEquipment()); }
@Override public String getName() { return "鞋子"; }
@Override public double getHP() { return hero.getHP(); }
@Override public double getMP() { return hero.getMP(); }
@Override public double getATK() { return hero.getATK(); }
@Override public double getDEF() { return hero.getDEF(); }
@Override public double getCRT() { return hero.getCRT(); }
@Override public double getCRTE() { return hero.getCRTE(); }
@Override public double getMS() { return hero.getMS() + 100; }
@Override public String getEquipment() { return hero.getEquipment() + getName() + ","; }
@Override public double getAB() { return hero.getAB(); }
}复制代码
2）无尽之刃：50%暴击 + 50%暴击效果
package com.brave.decorator.pesticide.equipment;
import com.brave.decorator.pesticide.hero.Hero;
/** * 无尽之刃:增加暴击率50%.暴击效果50% * @author Brave * */public class InfinitySword extends Equipment {
private Hero hero;
public InfinitySword(Hero hero) { this.hero = hero; }
@Override public void printHeroAttr() { System.out.println("name = " + getName()); System.out.println("生命值:HP = " + getHP()); System.out.println("魔法值:MP = " + getMP()); System.out.println("攻击力:ATK = " + getATK()); System.out.println("防御力:DEF = " + getDEF()); System.out.println("暴击率加成:CRT = " + getCRT()); System.out.println("暴击效果:CRTE = " + getCRTE()); System.out.println("移动速度加成:MS = " + getMS()); System.out.println("破甲加成:AB = " + getAB()); System.out.println(getEquipment().equals("") ? "" : "装备:equipment = " + getEquipment()); }
@Override public String getName() { return "无尽之刃"; }
@Override public double getHP() { return hero.getHP(); }
@Override public double getMP() { return hero.getMP(); }
@Override public double getATK() { return hero.getATK(); }
@Override public double getDEF() { return hero.getDEF(); }
@Override public double getCRT() { return hero.getCRT() + 0.5; }
@Override public double getCRTE() { return hero.getCRTE() + 0.5; }
@Override public double getMS() { return hero.getMS(); }
@Override public String getEquipment() { return hero.getEquipment() + getName() + ","; }
@Override public double getAB() { return hero.getAB(); }
}复制代码
3）破甲弓：100 攻击 + 100 破甲
package com.brave.decorator.pesticide.equipment;
import com.brave.decorator.pesticide.hero.Hero;
/** * 破甲弓:100攻击+100破甲 * @author Brave * */public class ArmorBow extends Equipment {
private Hero hero;
public ArmorBow(Hero hero) { this.hero = hero; }
@Override public void printHeroAttr() { System.out.println("name = " + getName()); System.out.println("生命值:HP = " + getHP()); System.out.println("魔法值:MP = " + getMP()); System.out.println("攻击力:ATK = " + getATK()); System.out.println("防御力:DEF = " + getDEF()); System.out.println("暴击率加成:CRT = " + getCRT()); System.out.println("暴击效果:CRTE = " + getCRTE()); System.out.println("移动速度加成:MS = " + getMS()); System.out.println("破甲加成:AB = " + getAB()); System.out.println(getEquipment().equals("") ? "" : "装备:equipment = " + getEquipment()); }
@Override public String getName() { return "破甲弓"; }
@Override public double getHP() { return hero.getHP(); }
@Override public double getMP() { return hero.getMP(); }
@Override public double getATK() { return hero.getATK() + 100; }
@Override public double getDEF() { return hero.getDEF(); }
@Override public double getCRT() { return hero.getCRT(); }
@Override public double getCRTE() { return hero.getCRTE(); }
@Override public double getMS() { return hero.getMS(); }
@Override public String getEquipment() { return hero.getEquipment() + getName() + ","; }
@Override public double getAB() { return hero.getAB() + 100; }
}
复制代码
4）冰痕之握：100 防御 + 100 魔法
package com.brave.decorator.pesticide.equipment;
import com.brave.decorator.pesticide.hero.Hero;
/** * 复活甲:100防御+100魔法值 * @author Brave * */public class IceMarkGrip extends Equipment {
private Hero hero;
public IceMarkGrip(Hero hero) { this.hero = hero; }
@Override public void printHeroAttr() { System.out.println("name = " + getName()); System.out.println("生命值:HP = " + getHP()); System.out.println("魔法值:MP = " + getMP()); System.out.println("攻击力:ATK = " + getATK()); System.out.println("防御力:DEF = " + getDEF()); System.out.println("暴击率加成:CRT = " + getCRT()); System.out.println("暴击效果:CRTE = " + getCRTE()); System.out.println("移动速度加成:MS = " + getMS()); System.out.println("破甲加成:AB = " + getAB()); System.out.println(getEquipment().equals("") ? "" : "装备:equipment = " + getEquipment()); }
@Override public String getName() { return "冰痕之握"; }
@Override public double getHP() { return hero.getHP(); }
@Override public double getMP() { return hero.getMP() + 100; }
@Override public double getATK() { return hero.getATK(); }
@Override public double getDEF() { return hero.getDEF() + 100; }
@Override public double getCRT() { return hero.getCRT(); }
@Override public double getCRTE() { return hero.getCRTE(); }
@Override public double getMS() { return hero.getMS(); }
@Override public String getEquipment() { return hero.getEquipment() + getName() + ","; }
@Override public double getAB() { return hero.getAB(); }
}
复制代码
5）泣血之刃：100 攻击 + 100 生命：
package com.brave.decorator.pesticide.equipment;
import com.brave.decorator.pesticide.hero.Hero;
/** * 泣血之刃:100攻击+100生命值 * @author Brave * */public class BloodSword extends Equipment {
private Hero hero;
public BloodSword(Hero hero) { this.hero = hero; }
@Override public void printHeroAttr() { System.out.println("name = " + getName()); System.out.println("生命值:HP = " + getHP()); System.out.println("魔法值:MP = " + getMP()); System.out.println("攻击力:ATK = " + getATK()); System.out.println("防御力:DEF = " + getDEF()); System.out.println("暴击率加成:CRT = " + getCRT()); System.out.println("暴击效果:CRTE = " + getCRTE()); System.out.println("移动速度加成:MS = " + getMS()); System.out.println("破甲加成:AB = " + getAB()); System.out.println(getEquipment().equals("") ? "" : "装备:equipment = " + getEquipment()); }
@Override public String getName() { return "泣血之刃"; }
@Override public double getHP() { return hero.getHP() + 100; }
@Override public double getMP() { return hero.getMP(); }
@Override public double getATK() { return hero.getATK() + 100; }
@Override public double getDEF() { return hero.getDEF(); }
@Override public double getCRT() { return hero.getCRT(); }
@Override public double getCRTE() { return hero.getCRTE(); }
@Override public double getMS() { return hero.getMS(); }
@Override public String getEquipment() { return hero.getEquipment() + getName() + ","; }
@Override public double getAB() { return hero.getAB(); }
}
复制代码
6）破军：200 攻击
package com.brave.decorator.pesticide.equipment;
import com.brave.decorator.pesticide.hero.Hero;
/** * 破军:200攻击 * @author Brave * */public class Breach extends Equipment {
private Hero hero;
public Breach(Hero hero) { this.hero = hero; }
@Override public void printHeroAttr() { System.out.println("name = " + getName()); System.out.println("生命值:HP = " + getHP()); System.out.println("魔法值:MP = " + getMP()); System.out.println("攻击力:ATK = " + getATK()); System.out.println("防御力:DEF = " + getDEF()); System.out.println("暴击率加成:CRT = " + getCRT()); System.out.println("暴击效果:CRTE = " + getCRTE()); System.out.println("移动速度加成:MS = " + getMS()); System.out.println("破甲加成:AB = " + getAB()); System.out.println(getEquipment().equals("") ? "" : "装备:equipment = " + getEquipment()); }
@Override public String getName() { return "破甲弓"; }
@Override public double getHP() { return hero.getHP(); }
@Override public double getMP() { return hero.getMP(); }
@Override public double getATK() { return hero.getATK() + 200; }
@Override public double getDEF() { return hero.getDEF(); }
@Override public double getCRT() { return hero.getCRT(); }
@Override public double getCRTE() { return hero.getCRTE(); }
@Override public double getMS() { return hero.getMS(); }
@Override public String getEquipment() { return hero.getEquipment() + getName() + ","; }
@Override public double getAB() { return hero.getAB(); }
}
复制代码
5，测试装饰模式，逐一为英雄装饰 6 件装备，打印日志查看装饰后的英雄属性：
package com.brave.decorator.pesticide;
import com.brave.decorator.pesticide.equipment.ArmorBow;import com.brave.decorator.pesticide.equipment.BloodSword;import com.brave.decorator.pesticide.equipment.Breach;import com.brave.decorator.pesticide.equipment.IceMarkGrip;import com.brave.decorator.pesticide.equipment.InfinitySword;import com.brave.decorator.pesticide.equipment.Shoes;import com.brave.decorator.pesticide.hero.Hero;import com.brave.decorator.pesticide.hero.MonkeyKing;
/** * 测试装饰模式 * * 在不修改任何底层代码的情况下.为对象赋予新的职责 * 装饰者模式:动态地将责任附加到对象上,若要拓展功能,装饰者提供了比继承更有弹性的替代方案 * * @author Brave * */public class Client {
public static void main(String[] args) {
System.out.println("*****************初始化英雄******************"); Hero hero = new MonkeyKing(); hero.printHeroAttr();
System.out.println("*****************装饰鞋子:100移速******************"); Hero shoes = new Shoes(hero); shoes.printHeroAttr(); System.out.println("*****************装饰无尽之刃:50%暴击+50%暴击效果******************"); Hero infinitySword = new InfinitySword(shoes); infinitySword.printHeroAttr(); System.out.println("*****************装饰破甲弓:100攻击+100破甲******************"); Hero armorBow = new ArmorBow(infinitySword); armorBow.printHeroAttr(); System.out.println("*****************装饰冰痕之握:100防御+100魔法******************"); Hero iceMarkGrip = new IceMarkGrip(armorBow); iceMarkGrip.printHeroAttr(); System.out.println("*****************装饰泣血之刃:100攻击+100生命******************"); Hero bloodSword = new BloodSword(iceMarkGrip); bloodSword.printHeroAttr(); System.out.println("*****************装饰破军:200攻击******************"); Hero breach = new Breach(bloodSword); breach.printHeroAttr(); }
}复制代码
6，打印日志输出，查看属性：
*****************初始化英雄******************name = 孙悟空生命值:HP = 100.0魔法值:MP = 100.0攻击力:ATK = 100.0防御力:DEF = 100.0暴击率加成:CRT = 0.2暴击效果:CRTE = 1.5移动速度加成:MS = 0.0*****************装饰鞋子:100移速******************name = 鞋子生命值:HP = 100.0魔法值:MP = 100.0攻击力:ATK = 100.0防御力:DEF = 100.0暴击率加成:CRT = 0.2暴击效果:CRTE = 1.5移动速度加成:MS = 100.0破甲加成:AB = 0.0装备:equipment = 鞋子,*****************装饰无尽之刃:50%暴击+50%暴击效果******************name = 无尽之刃生命值:HP = 100.0魔法值:MP = 100.0攻击力:ATK = 100.0防御力:DEF = 100.0暴击率加成:CRT = 0.7暴击效果:CRTE = 2.0移动速度加成:MS = 100.0破甲加成:AB = 0.0装备:equipment = 鞋子,无尽之刃,*****************装饰破甲弓:100攻击+100破甲******************name = 破甲弓生命值:HP = 100.0魔法值:MP = 100.0攻击力:ATK = 200.0防御力:DEF = 100.0暴击率加成:CRT = 0.7暴击效果:CRTE = 2.0移动速度加成:MS = 100.0破甲加成:AB = 100.0装备:equipment = 鞋子,无尽之刃,破甲弓,*****************装饰冰痕之握:100防御+100魔法******************name = 冰痕之握生命值:HP = 100.0魔法值:MP = 200.0攻击力:ATK = 200.0防御力:DEF = 200.0暴击率加成:CRT = 0.7暴击效果:CRTE = 2.0移动速度加成:MS = 100.0破甲加成:AB = 100.0装备:equipment = 鞋子,无尽之刃,破甲弓,冰痕之握,*****************装饰泣血之刃:100攻击+100生命******************name = 泣血之刃生命值:HP = 200.0魔法值:MP = 200.0攻击力:ATK = 300.0防御力:DEF = 200.0暴击率加成:CRT = 0.7暴击效果:CRTE = 2.0移动速度加成:MS = 100.0破甲加成:AB = 100.0装备:equipment = 鞋子,无尽之刃,破甲弓,冰痕之握,泣血之刃,*****************装饰破军:200攻击******************name = 破甲弓生命值:HP = 200.0魔法值:MP = 200.0攻击力:ATK = 500.0防御力:DEF = 200.0暴击率加成:CRT = 0.7暴击效果:CRTE = 2.0移动速度加成:MS = 100.0破甲加成:AB = 100.0装备:equipment = 鞋子,无尽之刃,破甲弓,冰痕之握,泣血之刃,破甲弓,复制代码
五，装饰模式的优点与缺点
装饰模式的优点:1,装饰模式与继承的目的都是扩展对象功能，但装饰模式比继承更加灵活性。 装饰模式允许系统动态决定添加装饰,或移除装饰 继承关系是静态的,在系统运行前决定2,可以灵活的"改造"对象,使用不同装饰器或改变排列组合顺序,实现多种组合
装饰模式的缺点: 装饰模式使用组合实现新功能的添加,相比继承的实现使用了较少的类 但由于装饰模式的特性,会产生比使用继承关系更多的对象 而这些对象都很相似,数量也较多,所以加大了系统错误的排查难度复制代码
模式到这里就简单的说完了,先备注一些后面要加入的部分
java 中使用的装饰模式-IO
装饰模式和其他模式的区别，例如和适配器
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发布于: 2021 年 11 月 05 日阅读数: 6
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