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Asked: 2026-05-22T23:00:50+00:00

I am using Eclipse to develop an Android application that plots Bluetooth data. I

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I am using Eclipse to develop an Android application that plots Bluetooth data.

I am using open source code, which has an existing solution that I want to extend and not replace to solve my development problem as stated above.

The open source code has a very nice and solid background thread that among other things continually logs BluetoothData to logcat even when I switch to a new activity.

Currently I have a solution which I am concerned about: I simply leverage a background thread method that writes to logcat to call a static plotData() method in my Plotting Activity. The result seems good. I get a nice plot. It clips along in real-time. Looks like an oscilloscope.

But I have received negative feedback about using the existing background thread coupled with a static method to plot the BluetoothDate. It has been suggested that I use a new thread, or add a handler, or use Async Task, or AIDL to solve my problem.

I have looked at all these solutions without success. Nothing seems to work like my static plotData() method. That is to say the existing background thread calls my static plotData() method which results in a real-time plot that looks great.

But I am still concerned about the negative feedback. I simply want to extend my existing background thread solution which I have done by having it call a static method to plot the data.

What are the problems I might face with this approach? Thread safety? Deadlock? I don’t know.

Why do people keep suggesting that I create a new thread, handler, Async Task, or Service to solve my problem when extending my existing thread to call a static method seems to work just fine?

Any suggestions? What are the problems with extending the existing thread to use a static method to plot the data in real-time?

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1 Answer

  1. Editorial Team

    Anyone who says that you should use AIDL for this is a loon who should not be listened to. 🙂 Also someone saying you need a Service if you don’t want to have your background thread running when the user is not viewing your activity.

    I’m not sure what you mean by “writes to logcat to call a static plotData().” You should write to logcat only for testing. Writing to logcat doesn’t cause a call to any Java method.

    If you are calling a static plotData() method on your Activity, you need to be extremely careful with this: first because it is difficult to figure out what activity instance should be called from there (it may go away at any time from the user finishing it, or be recreated as a new instance when the configuration changes, etc); and second because you can’t touch your app’s UI/view hierarchy from a background thread without risking that you corrupt its state (since the view hierarchy is single threaded).

    The general model one does for this kind of thing is to have a background thread doing some work, generating the next data to display. Once it is done with the work you send a message to the main thread to have it display the new data. AsyncTask can be a simple way to do this, it takes care of the underlying message sending and threading. You can also implement this yourself, at some point having a Handler that you post a Runnable on or send a Message to that once executed on the UI thread will update your view state.

    (Of course if you are using a SurfaceView, the whole point of that is to allow drawing to it outside of the main UI loop, so your background thread could just draw directly on to it as needed. Basically that is like writing a game.)

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