File Read&Write Android

Read:

FileReader fr = new FileReader("/data/data/com.example.steven.note/files/" + fileName);
int ch = 0;

while ((ch = fr.read()) != -1) {
      content += String.valueOf((char) ch);
}

Write

FileOutputStream outputStream = openFileOutput(filename, Context.MODE_PRIVATE);

outputStream.write(string.getBytes());

outputStream.close();