java timers :@

trscookie · 07-20-2006, 06:01 AM

hello, im trying to run this function on one of my java forms every second that the program is running, so i placed a timer in a thread, however i keep getting a null pointer exception?!

code:

Code:

        public void checkEvents() {
                ( new Thread() {
                    public void run() {
                        
                        while( true ) {
                            if( runClock == true ) {
                                timer.schedule( new task(), 1000 );
                            }
                        }
                    }
                }).start();
        }

        class task extends TimerTask {
            public void run() {
                print( "hello there" );
                runClock = true;
                timer.cancel();
            }
        };

cheers, trscookie.

mrcheeks · 07-20-2006, 06:38 AM

Where do you get a null pointer exception at what line? Is it the task which is null or something else?

trscookie · 07-20-2006, 07:04 AM

at this line:

Code:

timer.schedule( new task(), 1000 );

ive also tried:

Code:

timer.schedule( new task(), 0, 1000 );

ad get the same problem

mrcheeks · 07-20-2006, 10:02 AM

I think you forgot to initialize the timer.

Code:

timer = new Timer();

trscookie · 07-20-2006, 10:42 AM

oooop yea just changed that cheers, the other problem is that it doesnt seem to wait the time before printing "hello there" it just print millions of them. how can i get it to print one then wait then print the next?? cheers trscookie

xhi · 07-20-2006, 10:50 AM

i think youre looking for sleep..

mrcheeks · 07-20-2006, 10:50 AM

your print method is in the method run of your task. It will print hello until the timer is canceled. You are asking the timer to wait for one second...