在Swing中等待几秒钟

Question

I need to wait a few seconds between invoking two different methods in a program with Swing interface. Those methods are not related to the GUI.

firstMethod();
//The interface is changed by other methods
...
//I want to Wait five seconds
secondMethod();

I have tried using a Swing Timer but it does not work. Apparently, the Timer starts but is a non-blocking action, so secondMethod() is executed immediately. I can use sleep() , but that freezes the GUI for those five seconds, so the interface is not updated until after that, which I would prefer to avoid.

I have found here some recommendations to use Future<V> and I have read the Javadoc but I have never used ExecutorService before and I am afraid I may write a too complex piece of code for something that simple.

Any idea on how to do it?

Answer 1

Sounds like your code is something like:

firstMethod();

startTimer();

secondMethod();

I have tried using a Timer but it does not work

You can't just start a Timer and do nothing. When the timer fires you need to invoke the secondMethod(...) in the actionPerformed of the Timer.

Answer 2

Use Swing Timer instead of Java Timer and Thread.sleep.

Please have a look at How to Use Swing Timers

Timer timer = new Timer(5000, new ActionListener() {

    @Override
    public void actionPerformed(ActionEvent arg0) {            
        secondMethod();
    }
});
timer.setRepeats(false);
timer.start()

Answer 3

A timer won't just stop code execution like sleep does. You have to assign an ActionListener to it which will be notified when the time is up.

It goes something like this:

firstMethod();
Timer t = new Timer(5000);
t.setRepeats(false);
t.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            secondMethod();    
        }
    })
t.start();