it seems you're overwriting your String t
in every iteration of the while-loop. Try this:
StringBuilder result = new StringBuilder();
String inputLine = "";
while ((inputLine = in.readLine()) != null) {
result.append(inputLine);
}
fOut = openFileOutput("notes", MODE_PRIVATE);
fOut.write(result.toString().getBytes());
It creates a mutable StringBuilder and uses the resulting (immutable) String in the write call.
edit: I also recommend to always use curly brackets to indicate end of loop bodies, ommiting those can quickly lead to bugs, just check #gotofail for a recent example ;-)