Android sample bluetooth code to send a simple string via bluetooth -

i want send simple string data such 'a' android device other 1 via bluetooth. looked sample bluetooth code in android sdk complex me. cannot understand how can send specific data when press button. how can solve problem?

private outputstream outputstream; private inputstream instream;  private void init() throws ioexception {     bluetoothadapter blueadapter = bluetoothadapter.getdefaultadapter();     if (blueadapter != null) {         if (blueadapter.isenabled()) {             set<bluetoothdevice> bondeddevices = blueadapter.getbondeddevices();              if(bondeddevices.size() > 0) {                 object[] devices = (object []) bondeddevices.toarray();                 bluetoothdevice device = (bluetoothdevice) devices[position];                 parceluuid[] uuids = device.getuuids();                 bluetoothsocket socket = device.createrfcommsockettoservicerecord(uuids[0].getuuid());                 socket.connect();                 outputstream = socket.getoutputstream();                 instream = socket.getinputstream();             }              log.e("error", "no appropriate paired devices.");         } else {             log.e("error", "bluetooth disabled.");         }     } }  public void write(string s) throws ioexception {     outputstream.write(s.getbytes()); }  public void run() {     final int buffer_size = 1024;     byte[] buffer = new byte[buffer_size];     int bytes = 0;     int b = buffer_size;      while (true) {         try {             bytes = instream.read(buffer, bytes, buffer_size - bytes);         } catch (ioexception e) {             e.printstacktrace();         }     } }