Хранение данных, файлов в Android

void writeFile(final String fileName, final String text)
{
    try {
        FileOutputStream   fos;
        OutputStreamWriter osw;
        BufferedWriter     bw ;

        fos = openFileOutput(fileName, MODE_PRIVATE);
        osw = new OutputStreamWriter(fos);

        bw = new BufferedWriter(osw);
        bw.write(text);
        bw.close();
        Log.d(LOG_TAG, "Файл записан");
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

void readFile(final String fileName)
{
    try {
        FileInputStream   fis;
        InputStreamReader isr;
        BufferedReader    br ;

        fis = openFileInput(fileName);
        isr = new InputStreamReader(fis);

        br  = new BufferedReader(isr);
        String str = "";
        while ((str = br.readLine()) != null) {
            Log.d(LOG_TAG, str);
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

/*
 * Returns the current state of the primary shared/external
 * storage media
 */
public static String getExternalStorageState ();

/*
 * Returns the current state of the shared/external storage 
 * media at the given path.
 */
public static String getExternalStorageState (File path);

/* 
 * Возможные возвращаемые значения :
 * MEDIA_UNKNOWN, 
 * MEDIA_REMOVED, 
 * MEDIA_UNMOUNTED, 
 * MEDIA_CHECKING,
 * MEDIA_NOFS,
 * MEDIA_MOUNTED,
 * MEDIA_SHARED,
 * MEDIA_MOUNTED_READ_ONLY,
 * MEDIA_BAD_REMOVAL,
 * MEDIA_UNMOUNTABLE.
 */

/*
 * Return root of the "system" partition holding the core 
 * Android OS. Always present and mounted read-only.
 */
public static File getRootDirectory();
//-----------------------------------------------------------
/*
 * Return the user data directory.
 */ 
public static File getDataDirectory();
//-----------------------------------------------------------
/*
 * Return the download/cache content directory.
 */ 
public static File getDownloadCacheDirectory();
//-----------------------------------------------------------
/*
 * Return the primary shared/external storage directory. 
 * This directory may not currently be accessible if it has 
 * been mounted by the user on their computer, has been 
 * removed from the device, or some other problem has 
 * happened. You can determine its current state with 
 * getExternalStorageState().
 */
public static File getExternalStorageDirectory();
//-----------------------------------------------------------
/*
 * Get a top-level shared/external storage directory for 
 * placing files of a particular type. This is where the 
 * user will typically place and manage their own files, so
 * you should be careful about what you put here to ensure
 * you don't erase their files or get in the way of their 
 * own organization.
 */
public File   getExternalStoragePublicDirectory(String type);
//-----------------------------------------------------------
/*
 * Returns absolute paths to application-specific directories
 * on all shared/external storage devices where the 
 * application can place persistent files it owns. These 
 * files are internal to the application, and not typically
 * visible to the user as media.
 */
public File[] getExternalFilesDirs (String type);

/*
 * type :
 * Environment.DIRECTORY_MUSIC, 
 * Environment.DIRECTORY_PODCASTS,
 * Environment.DIRECTORY_RINGTONES, 
 * Environment.DIRECTORY_ALARMS, 
 * Environment.DIRECTORY_NOTIFICATIONS,
 * Environment.DIRECTORY_PICTURES, 
 * Environment.DIRECTORY_MOVIES
 */

final String MY_DIR   = "myDir" ;
final String FILENAME = "myFile";

void writeExternalFile()
{
    if (!Environment.getExternalStorageState().equals(
                         Environment.MEDIA_MOUNTED)) {
      Log.d(LOG_TAG, 
           "Доступ к внешнему хранилищу закрыт : " + 
               Environment.getExternalStorageState());
      return;
    }
    File path = Environment.getExternalStorageDirectory();
    path = new File(path.getAbsolutePath() +"/"+ MY_DIR);
    // Создаем каталог
    path.mkdirs();
    // Создаем File
    File file = new File(path, FILENAME);
    try {
      // открываем поток для записи
      BufferedWriter bw;
      bw = new BufferedWriter(new FileWriter(file));
      // пишем данные
      bw.write("Содержимое файла во внешнем хранилище");
      // закрываем поток
      bw.close();
      Log.d(LOG_TAG, "Файл записан : " + 
                      file.getAbsolutePath());
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
 
  void readExternalFile() {
    if (!Environment.getExternalStorageState().equals(
                         Environment.MEDIA_MOUNTED)) {
      Log.d(LOG_TAG, 
           "Доступ к внешнему хранилищу закрыт : " + 
               Environment.getExternalStorageState());
      return;
    }
    File path = Environment.getExternalStorageDirectory();
    path = new File(path.getAbsolutePath() +"/"+ MY_DIR);
    File file = new File(path, FILENAME);
    try {
      // открываем поток для чтения
      BufferedReader br;
      br = new BufferedReader(new FileReader(file));
      String str = "";
      // читаем содержимое
      while ((str = br.readLine()) != null) {
        Log.d(LOG_TAG, str);
      }
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }