Android implements the method of saving data in memory to sdcard

public static void writeToSdCard(String s) {
    try {
      File dst = new File("/sdcard/test_sensor/" + mName + ".txt");
      File parent = ();
      if(!()) {
        ();
      }
      FileOutputStream outStream = new FileOutputStream(dst, true);
      OutputStreamWriter writer = new OutputStreamWriter(outStream, "gb2312");
      (s);
      ("\n");
      ();
      ();// Remember to close      ();
    } catch (Exception e) {
      ("test result", "file write error");
      ();
    }
}