这是一个简单的空间游戏
Game类
public class Game {
private Room currentRoom;
private HashMap<String, Handler> handlers = new HashMap<String, Handler>();
public Game()
{
handlers.put("go", new HandlerGo(this));
handlers.put("bye", new HandlerBye(this));
handlers.put("help", new HandlerHelp(this));
createRooms();
}
private void createRooms()
{
Room outside;
Room lobby;
Room pub;
Room study;
Room 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("west", 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
}
public void showPrompt() {
System.out.println("你在" + currentRoom);
System.out.print("出口有: ");
System.out.print(currentRoom.getExitDesc());
System.out.println();
}
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 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;
}
// 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!");
}
}
消除代码复制的两个手段就是函数和父类。
if-else是一种硬编码,转换为框架。