writing log to file

Tool.java

public static void log_to_internal_file(String data, Context context) {
        try {
            // /data/data/jp.co.xxx.G3ProRemote/files
            OutputStreamWriter outputStreamWriter = new OutputStreamWriter(context.openFileOutput("debug_log.txt", Context.MODE_APPEND));
            String timeStamp = new SimpleDateFormat("yyyy:MM:dd_HH:mm:ss").format(Calendar.getInstance().getTime());
            outputStreamWriter.append(timeStamp + " " + data + "\n");
            outputStreamWriter.close();
        } catch (IOException e) {
            Log.e("Exception", "File write failed: " + e);
        }
    }

usage:
log_to_internal_file("abc", getContext());