Java IllegalThreadStateException on a basic timer

Question

I have code for an android app within android studio to run a method after a 1 second delay:

    new java.util.Timer().schedule(
            new java.util.TimerTask() {
                @Override
                public void run() {
                    loginClicked();
                }
            },
            1000
    );

However, it produces this error every time it executes:

java.lang.IllegalThreadStateException: A Looper must be associated with this thread.

I've basically grabbed it from this, so I don't really know what's up.

Why you're writing java.util.Timer instead of timer and TimerTask too? — Hayk Mkrtchyan, Oct 02 '18 at 09:47
Then remove loginClicked(); method. If it will work, then the problem is not in timer. — Hayk Mkrtchyan, Oct 02 '18 at 09:48
https://stackoverflow.com/questions/24579445/illegalthreadstateexception-thread-already-started-occurs-when-using-thread-star — Zafer Celaloglu, Oct 02 '18 at 09:52

score 2 · Accepted Answer · answered Oct 02 '18 at 10:03

You better to use Handler on Android at these situations.

TimerTask is pure java and you can see the differences & the other important info in here: https://stackoverflow.com/a/40339630/4409113

Some of reported problems with TimerTask include:

Can't update the UI thread
Memory leaks
Unreliable (doesn't always work)
Long running tasks can interfere with the next scheduled event

However, you can use the following codes:

final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
  @Override
  public void run() {
    //Do your things after 1000ms
     loginClicked();
  }
}, 1000);

Java IllegalThreadStateException on a basic timer

1 Answers1