Error maxTag: java.lang.RuntimeException: Can't create handler inside thread Thread[AsyncTask #5,5,main] that has not called Looper.prepare()

 The error message you are encountering, java.lang.RuntimeException: Can't create handler inside thread Thread[AsyncTask #5,5,main] that has not called Looper.prepare(), typically occurs when you try to update the UI from a background thread without using the proper mechanism.

In Android, UI updates should be performed on the main (UI) thread. In your case, it seems like you're trying to update the UI directly from the doInBackground method of an AsyncTask, which runs on a background thread.

To fix this issue, you should move the UI-related code to the onPostExecute method of the AsyncTask. This method is called on the main thread after the background processing is complete. Here's an example:

private class RFIDScanTask extends AsyncTask<Void, Void, Void> {

    @Override

    protected Void doInBackground(Void... voids) {

        // Simulate RFID scanning logic

        for (int i = 0; i < 10; i++) {

            if (isCancelled()) {

                // Break out of the loop if the task is cancelled

                break;

            }

            // Perform RFID scanning here

            // Simulate delay

            try {

                Thread.sleep(1000);

            } catch (InterruptedException e) {

                e.printStackTrace();

            }

        }

        return null;

    }

    @Override

    protected void onPostExecute(Void aVoid) {

        // RFID scanning completed

        isScanning = false;

        // Update UI from the main thread

        updateUIAfterScanning();

    }

}

private void updateUIAfterScanning() {

    runOnUiThread(new Runnable() {

        @Override

        public void run() {

            // Update UI elements here

            stopScanning();

        }

    });

}

In this example, I've introduced the updateUIAfterScanning method, which is called from the onPostExecute method. This method uses runOnUiThread to ensure that the UI updates are performed on the main thread.

Make sure to replace the stopScanning method call with the actual UI updates you want to perform after the RFID scanning is complete.

If you're not using an AsyncTask or have a different threading mechanism, the key is to ensure that any UI updates are done on the main (UI) thread.