设计模式 - 模板 | BangjinHu's Blog

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简介

在该模式中，一个抽象类公开定义了执行它的方法的方式/模板。它的子类可以按照需要重写方法实现，但是调用将以抽象类中定义的方式进行。

模板模式

1.创建一个抽象类它的模板方法被设置为final

public abstract class Game {
   abstract void initialize();
   abstract void startPlay();
   abstract void endPlay();

   //模板
   public final void play(){

      //初始化游戏
      initialize();

      //开始游戏
      startPlay();

      //结束游戏
      endPlay();
   }
}

2.创建扩展上述类的实体类

public class Cricket extends Game {

   @Override
   void endPlay() {
      System.out.println("Cricket Game Finished!");
   }

   @Override
   void initialize() {
      System.out.println("Cricket Game Initialized! Start playing.");
   }

   @Override
   void startPlay() {
      System.out.println("Cricket Game Started. Enjoy the game!");
   }
}

public class Football extends Game {

   @Override
   void endPlay() {
      System.out.println("Football Game Finished!");
   }

   @Override
   void initialize() {
      System.out.println("Football Game Initialized! Start playing.");
   }

   @Override
   void startPlay() {
      System.out.println("Football Game Started. Enjoy the game!");
   }
}

3.使用 Game 的模板方法 play() 来演示游戏的定义方式

public class TemplatePatternDemo {
   public static void main(String[] args) {

      Game game = new Cricket();
      game.play();
      System.out.println();
      game = new Football();
      game.play();      
   }
}

模板模式番外

1.创建抽象类

package Pattern_Design_Behavior.template_pattern;

public abstract class Hamburger {
    //默认是有生菜的
    private boolean lettuceHook = true;
    public void setLettuceHook(boolean lettuceHook){
        this.lettuceHook = lettuceHook;
    }

    public final void getHumburger(){
        topBread();
        if (lettuceHook){
            lettuce();
        }
        meat();
        bottomBread();
    }

    protected void topBread(){
        System.out.println("上面的面包");
    }

    protected void lettuce(){
        System.out.println("中间的生菜");
    }

    protected abstract void meat();

    private void bottomBread(){
        System.out.println("底部的面包");
    }
}

2.创建抽象类的实现类

package Pattern_Design_Behavior.template_pattern.impl;

import Pattern_Design_Behavior.template_pattern.Hamburger;

public class CodFishBurger extends Hamburger {
    @Override
    protected void meat() {
        System.out.println("深海鲟鱼");
    }
}

3.测试

package Pattern_Design_Behavior.template_pattern.impl;

import Pattern_Design_Behavior.template_pattern.Hamburger;

public class TemplatePattern {
    public static void main(String[] args) {
        System.out.println("第一个汉堡包");
        Hamburger codFishBurger = new CodFishBurger();
        codFishBurger.getHumburger();

        System.out.println();

        System.out.println("第二个汉堡包");
        Hamburger codFishBurgerTow = new CodFishBurger();
        codFishBurgerTow.setLettuceHook(false);
        codFishBurgerTow.getHumburger();
    }
}