NullPointerException error with Rendering

Question

I am getting this error whenever I press spacebar(to shoot the 'missile'), and I can't find out how to fix it, at all.

Exception in thread "Thread-0" java.lang.NullPointerException
    at com.game.main.Bullet.render(Bullet.java:26)
    at com.game.main.Controller.render(Controller.java:58)
    at com.game.main.Game.render(Game.java:155)
    at com.game.main.Game.run(Game.java:108)
    at java.lang.Thread.run(Thread.java:745)

I will list the code that is in the error as I have 9 classes.

The Bullet error line:

g.drawImage(tex.missile, (int)x, (int)y, null);

tex.missile is a BufferedImage variable from the texture class, and is set to

missile = ss.grabImage(2, 1, 32, 32);

ss is a SpriteSheet class and is set to new SpriteSheet(game.getSpriteSheet());

The SpriteSheet class just gets the SpriteSheet and just sets each square to a row/column etc. Everything there works as my Player & Enemy both work.

Controller error line:

tempBullet.render(g);

Game.render error line:

c.render(g);

Game.run error line:

render();

I highly doubt it has anything to do with the Game class, or anything like that, but I think it has to do with the Bullet class, but yet again. I could be, and most likely am wrong. I think that something may not be set correctly.

If you want me to show a whole class, I will. Just tell me which one you need.

EDIT: g.drawImage is inside of this method

public void render(Graphics g){ 
    g.drawImage(tex.missile, (int)x, (int)y, null);
}

Answer 1

A NullPointerException occurs if you're trying to perform an action (like a method call) on a null reference. So if you're getting this exception on this line g.drawImage(tex.missile, (int)x, (int)y, null);, then check if one of the following variables is null:

• g
• tex
• x
• y

x and y can be null, if you use a wrapper class like Integer. The provided null reference for the image observer (forth argument of the method drawImage) won't cause a NullPointerException, so there is no need to change something there.