Thread: nullpointer exception when adding Object to ArrayList

Done

Originally Posted by Norm

Are you saying the project is done?

If you are still getting the error: Please copy the full text of the error message and paste it here.

Oh sorry, I meant that I've editted the post, why can't i see the post anymore? did I made a mistake?

The error message is: java.lang.NullPointerException: null

and the code is

 
public class Game 
{
    private Parser parser;
    private Player player;
    private int moveLimit;
    private ArrayList<Room> rooms;
 
    /**
     * Create the game and initialise its internal map.
     */
    public Game() 
    {
        Room start = createRooms();
        parser = new Parser();
        player = new Player(start);
        moveLimit = 30;
        rooms = new ArrayList<Room>();
    }
 
    public static void main(String[] args)
    {
        Game game = new Game();
        game.play();
    }
 
    /**
     * Create all the rooms and link their exits together.
     */
    private Room createRooms()
    {
        Room mainRoom, livingRoom, bedroom, playRoom, kitchen, diningRoom, hallway, tortureRoom, 
        cellar, dungeon, lobby, bathroom, library, chamberOfSecrets, garden, artRoom, trapdoor;
 
        // create the rooms
        mainRoom = new Room("in the main room, in the middle of the castle");
        livingRoom = new Room("in the living room");
        playRoom = new Room("teleport");
        kitchen = new Room("in the kitchen");      
        garden = new Room("in the garden");
        diningRoom = new Room("in the dining room");
        hallway = new Room("in the hallway");
        tortureRoom = new Room("in the torture room, the room is filled with scary objects");
        cellar = new Room("in the cellar");
        dungeon = new Room("in the dungeon");
        library = new Room("you fell into a trapdoor, you can get out using the rope");
        lobby = new Room("in the lobby");
        bedroom = new Room("in the bedroom");
        bathroom = new Room("in the bathroom");
        chamberOfSecrets = new Room("in the CHAMBER OF SECRETS");
        artRoom = new Room("in the art room");
        trapdoor = new Room("You fell into a trapdoor");
 
        // lock certain rooms
        cellar.lockRoom();
        chamberOfSecrets.lockRoom();
 
        // initialise room exits
        mainRoom.setExit("east", diningRoom);
        mainRoom.setExit("south", kitchen);
        mainRoom.setExit("west", livingRoom);
 
        livingRoom.setExit("north", playRoom);
        livingRoom.setExit("east", mainRoom);
 
        playRoom.setExit("south", livingRoom);
 
        kitchen.setExit("north", mainRoom);
        kitchen.setExit("south", garden);
        kitchen.setExit("down", cellar);
 
        garden.setExit("north", kitchen);
 
        diningRoom.setExit("east", hallway);
        diningRoom.setExit("west", mainRoom);
 
        hallway.setExit("west", diningRoom);
        hallway.setExit("up", lobby);
 
        cellar.setExit("north", dungeon);
        cellar.setExit("east", library);
        cellar.setExit("south", tortureRoom);
        cellar.setExit("up", kitchen);
 
        dungeon.setExit("south", cellar);
 
        library.setExit("west", cellar);
 
        tortureRoom.setExit("north", cellar);
 
        lobby.setExit("north", bedroom);
        lobby.setExit("south", bathroom);
        lobby.setExit("west", artRoom);
        lobby.setExit("down", hallway);
 
        bedroom.setExit("south", lobby);
 
        bathroom.setExit("north", lobby);
 
        artRoom.setExit("east", lobby);
        artRoom.setExit("west", chamberOfSecrets);
 
        // add items to the room
        chamberOfSecrets.addItem("GOLD", ", THERE IS GOLD EVERYWHERE", 1000000);
 
        kitchen.addItem("chicken", ", a big roosted chicken", 20);
        kitchen.addItem("cooky", ", this is a magic cooky that will increase your ability's when you eat it", 5);
 
        bathroom.addItem("soap", ", a purple duck shaped soap", 6);
        bathroom.addItem("silverkey", ", you can use this key to open a door!", 5);
 
        dungeon.addItem("goldkey", ", you can use this key to open a door!", 10);
 
        library.addItem("map", ", There is a map on the wall of the bottom floor \n to see the map type 'show'", 5000); 
 
        rooms.add(garden);
        rooms.add(library);
        rooms.add(bedroom);
 
        // start game outside
        return mainRoom;   
    }

Originally Posted by Norm

Please copy full text of error message and paste it here. It should show where the error happened.
Here's a sample:

Exception in thread "main" java.lang.NullPointerException
	at TestCode12.main(TestCode12.java:108)

This shows the error happened at line 108 in the method: main in TestCode12

Oke sorry, I'm still learning

I've uploaded the game, can you please check it out?

http://rapidshare.com/files/1529024034/Versie%2008.zip

Is this what you need?

java.lang.NullPointerException
at Game.createRooms(Game.java:136)
at Game.<init>(Game.java:33)

I knew that is had a null value, I just don't know why because the method first creates a new Room object and than adds it to the ArrayList

garden = new Room("description");
rooms.add(garden);

I don't know how this possible can't work?