面向对象程序设计-java语言第七周学习——内部类(匿名函数)全 洛的博客-java

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); } }