多次调用startTimer方法（Java）

Question

So I've been browsing the web for answers but feel overwhelmed and can't seem to find an explanation of this. For one of my classes we were given an example with code very similar to what I'm using and I copied it (dangerous I know but not sure how else to go about it.)

I'm trying to make it so that when a button is pressed a JLabel reads a certain text and 5 seconds later that text disappears. I have been able to do this successfully, but there is a catch. I have 6 JButtons that share the same ActionListener which can, under the right conditions, call the startStatusTimer method.

If one button is pressed, and within 5 seconds another button is pressed, it starts another timer, and the more buttons I press the more timers I get that never seem to never stop. The text eventually goes away, but only after the 5 seconds has passed from the the first button is pressed.

I keep getting count values >5 printing out after pressing buttons multiple times within a few seconds but I do not see how this can be because of the if statement.

It does not seem like good coding practice to leave a bunch of timers running in the background so how do I stop them?

private void startStatusTimer()
{
    ActionListener taskPerformer = new ActionListener() 
    {
        int count=0;
        public void actionPerformed(ActionEvent event) 
        {
            count++;
            System.out.println(count);
            if(count>=5)
            {
                statusLabel.setText("");
                statusTimer.stop();
            }
        }
    };
    statusTimer = new Timer(second, taskPerformer);
    statusTimer.start();
}

The System.out.println is simply for debugging. Any help is greatly appreciated.

Answer 1

It does not seem like good coding practice to leave a bunch of timers running in the background

Generally, no, you don't want to have multiple Swing Timer s running if you can help it. They won't scale well (the more you add, the worst things become). Where you trying to do the same or similar things, try and use as few Timer s as possible.

Instead, try creating a single instance of the Timer ...

 public class ... {
     private Timer wipeOutTimer;

     public ...() {
          wipeOutTimer = new Timer(5000, new ActionListener() {
              public void actionPerformed(ActionEvent event) 
              {
                  statusLabel.setText("");
              }
          });
          wipeOutTimer.setRepeats(false);
    }

Then in your startStatusTimer you can check the state of the Timer ...

private void startStatusTimer() {
    if (!wipeOutTimer.isRunning()) {
        wipeOutTimer.start();
    }

This will ensure that no matter how many times you press buttons, while there will only ever be a single Timer running and it will only be started once within a 5 second period.

so how do I stop them?

This depends on what you are trying to do. You could use setRepeats(false) so timer will only run once. You could also use isRunning to check to see if the Timer is already running and even use restart to cause the timer to reset should you want to...

How can I make the timer restart to 5 seconds everytime the button is pressed?

Simply call restart

private void startStatusTimer() {
    if (!wipeOutTimer.isRunning()) {
        wipeOutTimer.start();
    } else {
        wipeOutTimer.restart();
    }

You can actually just call restart every time, but this illustrates some additional functionality you may no know about...