Question

This title may seem strange, so let me try to explain what I’m trying to do. I have several activity classes, each representing a different view in my application. My initial activity class gets loaded when the application launches. The user enters values and eventually a TCP socket is opened, and I then use AsyncTask to listen for and respond to messages from the server. I’d like for this AsyncTask class to essentially listen until the app is closed/error condition reached, and be able to update values in other activity classes after they are started. Does this make sense (it’s been a long, frustrating night)? I know that static activity class references are bad practice, and touching the UI thread from other activities is bad as well, but I’m having trouble finding a clean solution to this problem. Maybe using AsyncTask is not the best approach here? Should I be using a service instead or something else entirely?

Thanks in advance.

Answer 1

The user enters values and eventually a TCP socket is opened, and I then use AsyncTask to listen for and respond to messages from the server.

AsyncTask is designed for short-lived operations (e.g., flash reads, flash writes, Web service calls). Use your own background thread for indefinitely-long operations.

I’d like for this AsyncTask class to essentially listen until the app is closed/error condition reached

There is no such concept in Android of “app is closed”, any more than there is a concept on the Web of “app is closed”.

and be able to update values in other activity classes after they are started.

That sounds like a job for a service, not just some random thread or AsyncTask. For starters, once your original activity that started the background thread or AsyncTask is destroyed, you gotta gotta gotta get rid of the background thread or AsyncTask.

Should I be using a service instead or something else entirely?

I would strongly recommend you look into services.