Currently the code that generates and displays the list of exits from a room is contained in the Game class. This is not a particularly good design. Each room in the game is represented by a Room object. The Room object contains fields that store the information about that room's exits. Therefore it should seem like this program would be better if the code to generate a list of the exits for a room would be contained in the Room class. Make this improvement by adding a method named getExitString to the Room class. This method should return a String listing the exits from the room. For example, if the room has exits to the north and west, this method should return a String containing: "north west". Now that each Room is capable of generating a list of its own exits. Refactor the code in the Game class to take advantage of this functionality. I.e. anywhere the Game class generates a list of the exits from the current room, change it to use your getExitString method. Written Exercise 2: After making the above improvements to the code, imagine again that you would like to allow rooms to have a new type of exit (e.g. "up"). Now identify each class and method that you would have to change in order to add the new type of exit. Has the design improved? Why or why not?

Currently, the Game class generates the full description of the current room (including information about exits) and displays it. This is dealing with data of the Room class, so the Room class should be responsible for generating this description. Add a method called getLongDescription to the Room class that returns a String containing the description and exits of a room, and refactor the Game class to use it whenever the Game needs to print information about a Room.

In order to answer this question, you need to refer Game class code given below:

/** * This class is the main class of the "World of Zuul" application. * "World of Zuul" is a very simple, text based adventure game. Users * can walk around some scenery. That's all. It should really be extended * to make it more interesting! * * To play this game, create an instance of this class and call the "play" * method. * * This main class creates and initialises all the others: it creates all * rooms, creates the parser and starts the game. It also evaluates and * executes the commands that the parser returns. * * @author Michael Klling and David J. Barnes * @version 2016.02.29 */

public class Game { private Parser parser; private Room currentRoom; /** * Create the game and initialise its internal map. */ public Game() { createRooms(); parser = new Parser(); }

/** * Create all the rooms and link their exits together. */ private void createRooms() { Room outside, theater, pub, lab, office; // create the rooms outside = new Room("outside the main entrance of the university"); theater = new Room("in a lecture theater"); pub = new Room("in the campus pub"); lab = new Room("in a computing lab"); office = new Room("in the computing admin office"); // initialise room exits outside.setExits(null, theater, lab, pub); theater.setExits(null, null, null, outside); pub.setExits(null, outside, null, null); lab.setExits(outside, office, null, null); office.setExits(null, null, null, lab);

currentRoom = outside; // start game outside }

/** * Main play routine. Loops until end of play. */ public void play() { printWelcome();

// Enter the main command loop. Here we repeatedly read commands and // execute them until the game is over. boolean finished = false; while (! finished) { Command command = parser.getCommand(); finished = processCommand(command); } System.out.println("Thank you for playing. Good bye."); }

/** * Print out the opening message for the player. */ private void printWelcome() { System.out.println(); System.out.println("Welcome to the World of Zuul!"); System.out.println("World of Zuul is a new, incredibly boring adventure game."); System.out.println("Type 'help' if you need help."); System.out.println(); System.out.println("You are " + currentRoom.getDescription()); System.out.print("Exits: "); if(currentRoom.northExit != null) { System.out.print("north "); } if(currentRoom.eastExit != null) { System.out.print("east "); } if(currentRoom.southExit != null) { System.out.print("south "); } if(currentRoom.westExit != null) { System.out.print("west "); } System.out.println(); }

/** * Given a command, process (that is: execute) the command. * @param command The command to be processed. * @return true If the command ends the game, false otherwise. */ private boolean processCommand(Command command) { boolean wantToQuit = false;

if(command.isUnknown()) { System.out.println("I don't know what you mean..."); return false; }

String commandWord = command.getCommandWord(); if (commandWord.equals("help")) { printHelp(); } else if (commandWord.equals("go")) { goRoom(command); } else if (commandWord.equals("quit")) { wantToQuit = quit(command); }

return wantToQuit; }

// implementations of user commands:

/** * Print out some help information. * Here we print some stupid, cryptic message and a list of the * command words. */ private void printHelp() { System.out.println("You are lost. You are alone. You wander"); System.out.println("around at the university."); System.out.println(); System.out.println("Your command words are:"); System.out.println(" go quit help"); }

/** * Try to go in one direction. If there is an exit, enter * the new room, otherwise print an error message. */ private void goRoom(Command command) { if(!command.hasSecondWord()) { // if there is no second word, we don't know where to go... System.out.println("Go where?"); return; }

String direction = command.getSecondWord();

// Try to leave current room. Room nextRoom = null; if(direction.equals("north")) { nextRoom = currentRoom.northExit; } if(direction.equals("east")) { nextRoom = currentRoom.eastExit; } if(direction.equals("south")) { nextRoom = currentRoom.southExit; } if(direction.equals("west")) { nextRoom = currentRoom.westExit; }

if (nextRoom == null) { System.out.println("There is no door!"); } else { currentRoom = nextRoom; System.out.println("You are " + currentRoom.getDescription()); System.out.print("Exits: "); if(currentRoom.northExit != null) { System.out.print("north "); } if(currentRoom.eastExit != null) { System.out.print("east "); } if(currentRoom.southExit != null) { System.out.print("south "); } if(currentRoom.westExit != null) { System.out.print("west "); } System.out.println(); } }

/** * "Quit" was entered. Check the rest of the command to see * whether we really quit the game. * @return true, if this command quits the game, false otherwise. */ private boolean quit(Command command) { if(command.hasSecondWord()) { System.out.println("Quit what?"); return false; } else { return true; // signal that we want to quit } } }