Get all AsyncTasks that are executed and currently running in Android app

Question

I have a number of AsyncTask instances that are downloading some different content from the server. They run on executor:

final GetStationsTask getStationsTask = new GetStationsTask();
getStationsTask
        .executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, URL_STATIONS);

Currently I have 3 subclasses of AsyncTask, but this number will not stay the same. I am also implementing some kind of retrying for tasks that were not completed for different reasons, and I would like to download everything from the beginning, if at least one of the tasks was not finished correctly (the data was not received):

// mHandler = new Handler(); // an instance variable
mHandler.postDelayed(new Runnable() {
    @Override
    public void run() {
        if (!allDataSet()) {
            // here I want to cancel the tasks that are still running
            // and rerun all of them
        }
    }
}, 30000); // I give all the tasks 30 seconds to complete

For that I suppose I need to know which tasks are currently running, which tasks have finished correctly and which ones were cancelled, because if all the tasks get restarted, I need to cancel the running ones first to prevent the data from being received multiple times. Any ideas how to solve it?

Answer 1

Override the base AsyncTask, and use that as your base class for all AsyncTasks. Have the overriden task have a static list of running, cancelled and finished tasks. Then add each task to the relevant list in the base class methods.