Android Stop Runnable created in new Thread

Question

In my Android app I start a Runnable (called remoteUDPRunnable ) that establishes an UDP Connection with another device in a new Thread like this:

new Thread(remoteUDPRunnable).start();

I some cases, I want to stop that Thread (and cancel the UDP connection ) but I don't know how

I'have tried to keep the Thread instance in a variable and call myThread.interrupt() but it doesn't work.

I have also tried using a Handler like this:

final Handler remoteUDPRunnableHandler = new Handler();
remoteUDPRunnableHandler.post(remoteUDPRunnable);

So I can cancel it doing this:

remoteUDPRunnableHandler.removeCallbacks(remoteUDPRunnable);

That works but when I call the post(remoteUDPRunnable) method I get a NetworkOnMainThreadException . I have also tried to put the code inside the Runnable inside an AsyncTask but it doesn't work either.

Any ideas? I'm quite new on this and I'm a bit confused about it. Thanks

Answer 1

If you wrote the the class of remoteUDPRunnable yourself, you need to make sure (programmatically) the thread comes to an end.

The call thread.interrupt() only sets a flag in that thread. But if you never check it and do something with it, it's completely useless.

In your runnable you need to call Thread.interrupted() , if it returns true, initiate the shutdown of the thread. Be careful, the call Thread.interrupted() resets the interrupt flag of the executing thread.

Also, if a InterruptedException is thrown, the interrupt flag is also reset, so you might need to call Thread.interrupt() again in your runnable.