Question

I’m trying to use the HandlerThread class to manage thread in my application. The following code is working great :

public class ThreadA extends HandlerThread
{
    private void foo()
    {
        //do something
    }

    private void bar()
    {
        //Do something else
    }

    @Override
    public boolean handleMessage(Message msg) {
        switch(msg.what)
        {
            case 1:
            {
                this.foo();
                break;
            }

            case 2:
            {
                this.bar();
                break;
            }
        }
        return false;
    }

    @Override
    protected void onLooperPrepared()
    {
        super.onLooperPrepared();
        synchronized (this) {
            this.AHandler = new Handler(getLooper(),this);
            notifyAll();
        }
    }
}

1- Should i override the run() method ? In a “classic” thread most of the code is located in the run method.

2- Lets imagine i need my foo() method to be a infinite process (getting a video streaming for example).
What’s the best solution ?

• Overriding run with my foo() code ?

• Simply adding a sleep(xxx) in foo() :

  private void foo()
  {
  //do something
  sleep(100);
  foo();
  }

-Using a delayed message like :

private void foo()
{
    //do something
    handler.sendEmptyMessageDelayed(1,100);
}

PS : Asynctask will not cover my need , so do not bother to tell me to use it.

Thanks

Answer 1

I think you didn’t get the idea of HandlerThread. HandlerThread is designed to implement thread that handles messages. What this means is that it uses Looper.loop() in its run() method (and that’s why you shouldn’t override it). This in turn means that you don’t need to sleep in onHandleMessage() in order to prevent thread from exiting, as Looper.loop() already takes care of this.

To summarize:

1. No, do not override run().
2. You don’t need to do anything to keep thread alive.

If you want to learn/undestand more about HandlerThread, read about Looper and Handler classes.