Java模板模式

模板方法实例

创建一个 Game 抽象类，该类定义了将模板方法设置为final的操作，以使其无法被覆盖。 Cricket和Football是扩展Game并覆盖其方法的具体类。

无涯教程的演示类 TemplatePatternDemo 将使用 Game 演示模板模式的使用。

第1步 -  使用最终的模板方法创建一个抽象类。

Game.java

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

   //模板方法
   public final void play(){

      //调用初始化方法
      initialize();

      //调用开始游戏方法
      startPlay();

      //调用结束游戏方法
      endPlay();
   }
}

第2步 -  创建扩展上述类的具体类。

Cricket.java

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!");
   }
}

Football.java

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!");
   }
}

第3步 -  使用 Game 的模板方法play()演示定义的玩游戏方式。

TemplatePatternDemo.java

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

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

第4步 -  验证输出。

Cricket Game Initialized! Start playing.
Cricket Game Started. Enjoy the game!
Cricket Game Finished!

Football Game Initialized! Start playing.
Football Game Started. Enjoy the game!
Football Game Finished!