面向对象程序设计-java语言第七周学习——内部类(匿名函数)

傷城~ 2023-02-14 06:55 38阅读 0赞

城堡的Handler类  
在第5周的城堡程序那里，我们做的Handler是需要在构造的时候注入Game的。那么，在学习了内部类之后，能否用Game的内部类来实现这些Handler呢？应该怎么做？

#### 方法：Handler为接口，在Game.java构造函数里用匿名类完成go,bye,help功能 ####

#### Game.java ####

package castle;
    
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.Scanner;
    
    public class Game { 
    	private Room currentRoom;
    	private HashMap<String, Handler> handlers = new HashMap<String, Handler>();
    	protected ArrayList<String> cmds = new ArrayList<String>();
    
    	public Game() { 
    		handlers.put("bye", new Handler() { 
    			@Override
    			public void doCmd(String word) { 
    
    			}
    
    			@Override
    			public boolean isBye() { 
    				return true;
    			}
    		});
    		handlers.put("help", new Handler() { 
    			@Override
    			public void doCmd(String word) { 
    				System.out.println("迷路了吗？你可以做的命令有：" + cmds);
    
    				System.out.println("如：\tgo east");
    			}
    
    			@Override
    			public boolean isBye() { 
    				return false;
    			}
    		});
    		handlers.put("go", new Handler() { 
    			@Override
    			public void doCmd(String word) { 
    				goRoom(word);
    			}
    
    			@Override
    			public boolean isBye() { 
    				return false;
    			}
    		});
    		for (String cmd : handlers.keySet()) { 
    			cmds.add(cmd);
    		}
    
    		createRooms();
    
    	}
    
    	private void createRooms() { 
    		Room outside, lobby, pub, study, bedroom, inside, bedroomup;
    
    		// 制造房间
    
    		outside = new Room("城堡外");
    		inside = new Room("城堡内");
    		lobby = new Room("大堂");
    		pub = new Room("小酒吧");
    		study = new Room("书房");
    		bedroom = new Room("卧室");
    		bedroomup = new Room("卧室二楼");
    // hoteldown = new Room("宾馆一楼");
    // hotelup = new Room("宾馆二楼");
    		// 设置房间故事
    		outside.setNarration("城堡外", "恭喜你逃出了城堡");
    		inside.setNarration("城堡内", "你现在在城堡的一个恐怖黑暗的广场上");
    		lobby.setNarration("大堂", "你来到了城堡的大堂，大堂里面有着恐怖的石像");
    		pub.setNarration("小酒吧", "这是一间幽深的酒吧，傍边到处是黑色的酒瓶，还有这恐怖的音乐在播放着");
    		study.setNarration("书房", "这是城堡的书房，里面记载着这个城堡的过去");
    		bedroom.setNarration("卧室", "你来到了城堡主人的卧室，这里是最黑暗的地方，你的心跳跳的越来越快，快点离开这里吧！");
    		bedroomup.setNarration("卧室二楼", "恭喜你来到了城堡主人的卧室二楼，并且发现了一个箱子，你打开箱子后找到了钥匙，请拿着钥匙快速逃出城堡吧！");
    
    		// 初始化房间的出口
    		outside.setExit("south", inside);
    		inside.setExit("north", outside);
    		inside.setExit("east", lobby);
    		inside.setExit("south", study);
    		inside.setExit("west", pub);
    		lobby.setExit("west", inside);
    		pub.setExit("east", inside);
    		study.setExit("north", inside);
    		study.setExit("east", bedroom);
    		bedroom.setExit("west", study);
    		bedroom.setExit("up", bedroomup);
    		bedroomup.setExit("down", bedroom);
    
    		currentRoom = inside; // 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。任务：你需要在城堡内找到宝箱钥匙并带到城堡外去。");
    		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() { 
    		String currentnarration = currentRoom.getNarration(currentRoom.toString());
    		System.out.println("你在" + currentRoom + "\n场景描述：" + currentnarration);
    		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]);
    			String value = "";
    			if (words.length > 1)
    				value = words[1];
    			if (handler != null) { 
    				handler.doCmd(value);
    				if (handler.isBye()) { 
    					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 { 
    	public void doCmd(String word) { 
    	}
    
    	public boolean isBye() { 
    		return false;
    	}
    }

### Room.java ###

package castle;
    
    import java.util.HashMap;
    
    public class Room { 
        private String description;
        private HashMap<String, Room> exits = new HashMap<String, Room>();
        private HashMap<String, String> narration = new HashMap<String, String>();
        
        public Room(String description) 
        { 
            this.description = description;
        }
        public void setExit(String dir, Room room) { 
        	exits.put(dir, room);
        }
        public void setNarration(String room, String narr) { 
        	narration.put(room, narr);
        }
        @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);
        }
        public String getNarration(String direction) { 
        	return narration.get(direction);
        }
    }