public void closeFileOutputStream() {
    if (txFileOutputStream != null) {
      try {
        txFileOutputStream.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
      txFileOutputStream = null;
    }
    if (stFileOutputStream != null) {
      try {
        stFileOutputStream.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
      stFileOutputStream = null;
    }
    if (qFileOutputStream != null) {
      try {
        qFileOutputStream.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
      qFileOutputStream = null;
    }
  }