Question

I am a New B to Android. I have been Able to get the Battery Status/Level with the Following Code:

private void BattStatus() {
        BroadcastReceiver batteryLevelReceiver = new BroadcastReceiver() {
            public void onReceive(Context context, Intent intent) {
                context.unregisterReceiver(this);
                int rawlevel = intent.getIntExtra("level", -1);
                int scale = intent.getIntExtra("scale", -1);
                int level = -1;
                if (rawlevel >= 0 && scale > 0) {
                    level = (rawlevel * 100) / scale;
                }
                batteryLevel = level;
                BattStatus.setText("Battery Level : " + batteryLevel + "%");

            }
        };
        IntentFilter batteryLevelFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        registerReceiver(batteryLevelReceiver, batteryLevelFilter);
    }

I would Like to Store the Battery Level In A text file (Using a thread). Code :

public final Runnable DBThread = new Runnable() {
        String AllInfo = batteryLevel+"%"+" , "+new SimpleDateFormat("HH:mm , dd.MM.yy ").format(new Date());
        public void run() {
            try {
                Log.d("DBThread","Battery :"+batteryLevel);
                Log.d("DBThread","Updating DB");
                myDbHelper.CreateAndWriteFile(sdDir+"/", AllInfo );
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        mHandler.postAtTime(this, SystemClock.uptimeMillis() + 2000);
        Log.d("DBThread","Updated DB");
        Log.d("DBThread",AllInfo);

    }

Unfortunately the Battery Status/Level returns 0% in the text file, when I test it using the Log function in the thread it returns the correct value.

Please could some one be so kind to tell me what I am doing wrong or what I am not doing, and maybe provide me with a code snippet as I am new to Development.And Sorry If My Post is incorrect First timer on Stack Overflow 🙂

Thank you very much!

Answer 1

This is not a Thread. This is a Runnable, which is a piece of code that is made to run in a Thread.

In your case, it runs in the handler thread, most likely the UI Thread.

You probably start your thread before receiving the battery status, hence writing the default value (0) to the file.

You don’t need a thread for that. You can write to the file immediately after your receive the broadcast, in the onReceive method.

Edit

There are a few things that don’t work in your code. You unregister the broadcast receiver, hence you don’t receive the battery level after the first time.

You write the batteryLevel value without knowing if it has indeed been modified

You write every 2 seconds without knowing there has been a change.

I would suggest that you don’t unregister the BR, so you receive all battery level change. Then, in the onReceive, you append to the file the date and new value.