NullPointerException - Programmers Heaven

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Categories

Welcome to the new platform of Programmer's Heaven! We apologize for the inconvenience caused, if you visited us from a broken link of the previous version. The main reason to move to a new platform is to provide more effective and collaborative experience to you all. Please feel free to experience the new platform and use its exciting features. Contact us for any issue that you need to get clarified. We are more than happy to help you.

NullPointerException

Hello,

I recently started following some Java tutorials. (Game Programming series on youtube by TheChernoProject)
I'm now at episode 5 and it's the first time we need to run our code (in debug mode).
I have exactly the same code as the tutor, but i get a Null Pointer Exception error. Can someone please take a look at the code and explain what the problem is?

the code is:
[code]package com.sarranoob.lucid;

import java.awt.Canvas;
import java.awt.Dimension;
import javax.swing.JFrame;

public class Game extends Canvas implements Runnable {

private static final long serialVersionUID = 1L;

public static int width = 300;
public static int height = width / 16 * 9;
public static int scale = 3;

private Thread thread;
private JFrame frame;
private boolean running = false;

public Game() {
Dimension size = new Dimension(width * scale, height * scale);
setPreferredSize(size);
}

public synchronized void start() {
running = true;
thread = new Thread(this, "Display");
thread.start();
}

public synchronized void stop() {
running = false;
try{
thread.join();
} catch(InterruptedException e) {
e.printStackTrace();
}

}

public void run() {
while (running) {
System.out.println("Testing...");
}
}

public static void main(String[] args) {
Game game = new Game();
game.frame.setResizable(false);
game.frame.setTitle("Lucid Alpha Testing");
game.frame.add(game);
game.frame.pack();
game.frame.setLocationRelativeTo(null);
game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
game.frame.setVisible(true);
game.start();
}

}
[/code]

and the error:
[color=Red]Exception in thread "main" java.lang.NullPointerException
at com.sarranoob.lucid.Game.main(Game.java:48)[/color]

line 48 (where the error occurred) is:
game.frame.setResizable(false);

Thanks on advance.
Sign In or Register to comment.