java_castle

java类与对象的实例以及可扩展性

• game.java

	package castle;
	import java.util.HashMap;
	import java.util.Scanner;
	public class Game {
	private Room currentRoom;
	private HashMaphandlers =new HashMap();  
	public Game() 
	{
		//handlers.put("go", new HandlerGo());
		handlers.put("bye", new HandlerBye(this));
		handlers.put("help", new HandlerHelp(this));
		handlers.put("go", new HandlerGo(this));
		createRooms();
	}
	private void createRooms()
	{
	    Room outside, lobby, pub, study, bedroom;    
	    //	制造房间
	    outside = new Room("城堡外");
	      lobby = new Room("大堂");
	      	pub = new Room("小酒吧");
	      study = new Room("书房");
	    bedroom = new Room("卧室");      
	    //	初始化房间的出口
	    outside.setExit("east", lobby);
	    outside.setExit("south", study);
	    outside.setExit("north", pub);
	      lobby.setExit("west", outside);
	        pub.setExit("east", outside);
	      study.setExit("north", outside);
	      study.setExit("east", bedroom);
	    bedroom.setExit("west",study);
	      lobby.setExit("up", pub);
	        pub.setExit("down", lobby);
	    currentRoom = outside;  //	从城堡门外开始
	}
	private void printWelcome() {
	    System.out.println();
	    System.out.println("欢迎来到城堡！");
	    System.out.println("这是一个超级无聊的游戏。");
	    System.out.println("如果需要帮助，请输入 'help' 。");
	    System.out.println();
	    showPrompt();       
	}
	// 以下为用户命令
	public void goRoom(String direction) 
	{
	    Room nextRoom = currentRoom.getExit(direction);   
	    if (nextRoom == null) {
	        System.out.println("那里没有门！");
	    }
	    else {
	        currentRoom = nextRoom;
	        showPrompt();
	    }
	}    
	public void showPrompt() {
		 System.out.println("现在你在" + currentRoom);
	     System.out.print("出口有：");
	     System.out.print(currentRoom.getExitDesc());
	     System.out.println();
	}  
	public void play() {
		Scanner in = new Scanner(System.in);
		while ( true ) {
			String line = in.nextLine();
			String[] words = line.split(" ");
			Handler handler=handlers.get(words[0]);//handler的子类赋给了父类
			String value="";
			if(words.length>1)
				value=words[1];
			if(handler !=null) {
				handler.doCmd(value);
				if(handler.isBye())
					break;
					}
	//    		if ( words[0].equals("help") ) {
	//    			printHelp();
	//    		} else if (words[0].equals("go") ) {
	//    			goRoom(words[1]);
	//    		} else if ( words[0].equals("bye") ) {
	//    			break;
	//    		}
	//    }	 
		}
		in.close();
	}	
	public static void main(String[] args) {		
		Game game = new Game(); 
		game.printWelcome();
		game.play();
	    System.out.println("感谢您的光临。再见！");       
	}
}

• Handler.java

package castle;
public class Handler {

protected Game game;

public Handler(Game game) {
	this.game=game;
}
public void doCmd(String word) {}
public boolean isBye() {return false;}
}

• HandlerBye.java

	package castle;
	
	public class HandlerBye extends Handler {
		public HandlerBye(Game game) {
		super(game);
	}
	@Override
	public boolean isBye() {
		// TODO Auto-generated method stub
		return true;
		
	}


}

• HandlerGo.java

	package castle;
	
	public class HandlerGo extends Handler {
	public HandlerGo(Game game) {
		super(game);
	}
	@Override
	public void doCmd(String word) {
		game.goRoom(word);
	}

}

• HandlerHelp.java

  	package castle;
  	
  	public class HandlerHelp extends Handler {
  	public HandlerHelp(Game game) {
  		super(game);
  	}
    @Override
  	public void doCmd(String word) {
  		System.out.println("迷路了吗？你可以做的命令有：go bye help");
  	      System.out.println("如：\tgo east");
  	}
  
  }

• Room.java

  	package castle;
  	
  	import java.util.HashMap;
  
  
  	public class Room {
     	private String description;
    	 private HashMap exits=new HashMap();
  
      public Room(String description) 
      {
          this.description = description;
      }
      public void setExit(String dir,Room room) {
      	exits.put(dir, room);
      	
      }
      
      @Override
      public String toString()
      {
          return description;
      }
      
      public String getExitDesc() {
      	StringBuffer sb=new StringBuffer();
      	for(String dir:exits.keySet()) {
      		sb.append(dir);
      		sb.append(' ');		
      	}
      	return sb.toString();
      	
      }
      public Room getExit(String direction) {
      	return exits.get(direction);
      }
  }