write to a sdcard file

public static void FileWriterInit()

{

try

{

File sdCard = Environment.getExternalStorageDirectory();

File dir = new File(sdCard.getAbsolutePath() + "/webprefetch");

dir.mkdirs();

File file = new File(dir, mFileName);

mFos = new FileOutputStream(file);

} catch (Exception e)

{

android.util.Log.d("Debug", e.getMessage());

}

}

public static void FileWriteClose()

{

try

{

mFos.close();

} catch (Exception e)

{

android.util.Log.d("Debug", e.getMessage());

}

}

        public static void FileWrite()

        {

                 mFos.write(a_str.getBytes());

        }