Proper way to chain 2 async tasks in android

Question

I have two async tasks, namely task 1 and task 2.

I need to run task 1 first and then task 2 just after but I do not want to couple the two by calling task 2 in the onPostExecute implementation of task 1; because I use task 1 as stand alone in other circumstances.

I there a way to have the two async tasks defined without being bounded to each other and chain them in specific circumstances?

Thank you very much for your help.

Answer 1

You can try something like this:

final Executor directExecutor = new Executor() {
  public void execute(Runnable r) {
    r.run();
  }
};
AsyncTask.execute(new Runnable() {
  task1.executeOnExecutor(directExecutor, params1);
  task2.executeOnExecutor(directExecutor, params2);
});

I don't have android SDK on my machine now, so I can't verify it.

Answer 2

You can do the following:

YourAsyncClass1 thread1 = new YourAsyncClass1();
thread1.execute(inputArgument1);

    try {
        outputResult1 = thread1.get();
    } catch (InterruptedException e) {
        e.printStackTrace();
    } catch (ExecutionException e) {
        e.printStackTrace();
    }
if(outputResult1 == true /*Or expected result*/){
  YourAsyncClass2 thread2 = new YourAsyncClass2();
  thread2.execute(inputArgument2);
}