RuntimeException error - How/Why am I getting it?

Newbie & Debugging Questions
#1

Can anyone explain to me what a RuntimeException is?

I’m getting it from these bits of code when I try to do something when the secs get to 0 :


 t = new Thread(){
			 public void run() {
				  while(game_active) {
				  secs = secs - 1;
				   try 
				   {
					Thread.sleep(1000);
				   } catch (InterruptedException e) {
					e.printStackTrace();
				   }
				  }
				 }
				};
				t.start();



public void update(){
if( secs == 0)
		  {
			  GameOver();
		  }
}
// GameOver
	  private void GameOver()
	  {
		 Dialog.alert("Game Over!");
	  }

Or if i change it i get an illegalstateexcpetion, however if i use System.exit(0) it simply closes it, no errors.

Any ideas?

#2

Can you post the stack trace (all of the error) please?

#3

Secs is being used / changed in separate threads. Unless you know what you’re doing, you really should NOT be making additional threads. Why do you want to count seconds like this? Don’t you have a deltaTime somewhere in your gameloop, which you could use to count time passed?

EDIT: Forgot an important “NOT” there…phew

#4

I’m using the BlackBerry JDE so i dont have deltaTime so i need to count in this way, I tried using a Timer and TimerTask but that was given me errors as well.

It tells me there is no stack trace.
It just repeats saying, NO STACK TRACE

how i can i get the same result using the two threads?

#5

Two threads wont cause exceptions like this, he’s pointing out that multiple threads handling the same non-volatile or synchronized variable will have problems. One could update the value the same time as the other, and you could have funky effects.

Why are you using multiple threads?

#6

You could use this timer instead of a thread:


public class SimpleTimer {
	private long cachedTime;

	public SimpleTimer() {
		reset();
	}

	public void reset() {
		cachedTime = System.currentTimeMillis();
	}

	public long getElapsed() {
		return System.currentTimeMillis() - cachedTime;
	}
}

Example to keep track of seconds:


/* Before you inititialize your first thread */
final SimpleTimer secondCounter = new SimpleTimer();

/* In your run method: */
if (secondTimer.getElapsed() >= 1000) {
	seconds -= 1;
	/* Timer has reached one second, reset the timer */
	secondTimer.reset();
}

There’s no need to use a thread for a task so simple, use a simple timer! ;D
lol, hope it helps mate.

#7

A very good solution :slight_smile:

#8

Yeah, that solution to keep track of time is sufficient. That crazy thread stuff you’re doing is a bad idea mmmkay?

#9

Thanks, i didnt know it would be that easy :slight_smile:

#10

Simple: Your program runs timely into an exceptionally problematic section of code.

Sorry, couldn’t resist ;D

#11

Well done :stuck_out_tongue: