Searching for simple bluetooth to bluetooth messages tutorial or example

Question

Hi,
I want to send messages from 1 mobile phone to another one using Bluetooth but I can't find any simple tutorial or example with this type of bluetooth use.
So i'm asking for your help :) any simple tutorial/example for bluetooth messages between devices?
Thanks in advance

Answer 1

import java.util.Vector;
import java.io.IOException;
import javax.microedition.io.Connector;
import javax.microedition.io.ConnectionNotFoundException;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.TextField;
import javax.microedition.lcdui.StringItem;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.ChoiceGroup;
import javax.microedition.lcdui.Choice;
import javax.bluetooth.LocalDevice;
import javax.bluetooth.RemoteDevice;
import javax.bluetooth.DiscoveryAgent;
import javax.bluetooth.DataElement;
import javax.bluetooth.DeviceClass;
import javax.bluetooth.UUID;
import javax.bluetooth.DiscoveryListener;
import javax.bluetooth.ServiceRecord;
import javax.bluetooth.L2CAPConnectionNotifier;
import javax.bluetooth.L2CAPConnection;
import javax.bluetooth.BluetoothStateException;
import javax.bluetooth.BluetoothConnectionException;
import javax.bluetooth.ServiceRegistrationException;
public class ChatController extends MIDlet implements CommandListener
private Display display = null;
private Form mainForm = null;
private ChoiceGroup devices = null;
private TextField inTxt = null;
private TextField outTxt = null;
private Command exit = null;
private Command start = null;
private Command connect = null;
private Command send = null;
private Command select = null;
private StringItem status = null;
private LocalDevice local = null;
private RemoteDevice rDevices[];
private ServiceRecord service = null;
private DiscoveryAgent agent = null;
private L2CAPConnectionNotifier notifier;
private L2CAPConnection connection = null;
private static final String UUID_STRING = "112233445566778899AABBCCDDEEFF";
private boolean running = false;
public ChatController()
super();
display = Display.getDisplay(this);
     mainForm = new Form("CHAT");
     devices = new ChoiceGroup(null,Choice.EXCLUSIVE);
     inTxt = new TextField("incoming msg:","",256,TextField.ANY);
     outTxt = new TextField("outgoing msg:","",256,TextField.ANY);
     exit = new Command("EXIT",Command.EXIT,1);
     start = new Command("START",Command.SCREEN,2);
     connect = new Command("CONNECT",Command.SCREEN,2);
     send = new Command("SEND",Command.SCREEN,2);
     select = new Command("SELECT",Command.SCREEN,2);
     status = new StringItem("status : ",null);
     mainForm.append(status);
     mainForm.addCommand(exit);
     mainForm.setCommandListener(this);
protected void startApp() throws MIDletStateChangeException
running = true;
     mainForm.addCommand(start);
mainForm.addCommand(connect);
     display.setCurrent(mainForm);
try
local = LocalDevice.getLocalDevice();
     agent = local.getDiscoveryAgent();
catch(BluetoothStateException bse)
status.setText("BluetoothStateException unable to start:"+bse.getMessage());
          try
          Thread.sleep(1000);     
          catch(InterruptedException ie)
notifyDestroyed();
protected void pauseApp()
running = false;
     releaseResources();
protected void destroyApp(boolean uncond) throws MIDletStateChangeException
running = false;
     releaseResources();
public void commandAction(Command cmd,Displayable disp)
if(cmd==exit)
     running = false;
          releaseResources();
          notifyDestroyed();
else if(cmd==start)
     new Thread()
               public void run()
                    startServer();
               }.start();
else if(cmd==connect)
          status.setText("searching for devices...");
                    mainForm.removeCommand(connect);
                    mainForm.removeCommand(start);
                    mainForm.append(devices);
                    DeviceDiscoverer discoverer = new DeviceDiscoverer(ChatController.this);
                    try
                         agent.startInquiry(DiscoveryAgent.GIAC,discoverer);
                    catch(IllegalArgumentException iae)
status.setText("BluetoothStateException :"+iae.getMessage());
                    catch(NullPointerException npe)
status.setText("BluetoothStateException :"+npe.getMessage());
                    catch(BluetoothStateException bse1)
status.setText("BluetoothStateException :"+bse1.getMessage());
else if(cmd==select)
                    status.setText("searching devices for service...");
                         int index = devices.getSelectedIndex();
                         mainForm.delete(mainForm.size()-1);//deletes choiceGroup
                         mainForm.removeCommand(select);
                         ServiceDiscoverer serviceDListener = new ServiceDiscoverer(ChatController.this);
                         int attrSet[] = {0x0100}; //returns service name attribute
UUID[] uuidSet = {new UUID(UUID_STRING,false)};
                         try
                              agent.searchServices(attrSet,uuidSet,rDevices[index],serviceDListener);
                         catch(IllegalArgumentException iae1)
status.setText("BluetoothStateException :"+iae1.getMessage());
                    catch(NullPointerException npe1)
status.setText("BluetoothStateException :"+npe1.getMessage());
                    catch(BluetoothStateException bse11)
status.setText("BluetoothStateException :"+bse11.getMessage());
else if(cmd==send)
                         new Thread()
                                   public void run()
                                        sendMessage();
                                   }.start();
//this method is called from DeviceDiscoverer when device inquiry finishes
public void deviceInquiryFinished(RemoteDevice[] rDevices,String message)
this.rDevices = rDevices;
     String deviceNames[] = new String[rDevices.length];
     for(int k=0;k<rDevices.length;k++)
     try
          deviceNames[k] = rDevices[k].getFriendlyName(false);
     catch(IOException ioe)
     status.setText("IOException :"+ioe.getMessage());
for(int l=0;l<deviceNames.length;l++)
     devices.append(deviceNames[l],null);
mainForm.addCommand(select);
     status.setText(message);
//called by ServiceDiscoverer when service search gets completed
public void serviceSearchFinished(ServiceRecord service,String message)
     String url = "";
this.service = service;
     status.setText(message);
     try
     url = service.getConnectionURL(ServiceRecord.NOAUTHENTICATE_NOENCRYPT,false);     
     catch (IllegalArgumentException iae1)
try
     connection = (L2CAPConnection)Connector.open(url);
          status.setText("connected...");
          new Thread()
          public void run()
               startReciever();
          }.start();
catch(IOException ioe1)
status.setText("IOException :"+ioe1.getMessage());
// this method starts L2CAPConnection chat server from server mode
public void startServer()
status.setText("server starting...");
     mainForm.removeCommand(connect);
     mainForm.removeCommand(start);
     try
          local.setDiscoverable(DiscoveryAgent.GIAC);
          notifier = (L2CAPConnectionNotifier)Connector.open("btl2cap://localhost:"+UUID_STRING+";name=L2CAPChat");
          ServiceRecord record = local.getRecord(notifier);
          String conURL = record.getConnectionURL(ServiceRecord.NOAUTHENTICATE_NOENCRYPT,false);
          status.setText("server running...");
          connection = notifier.acceptAndOpen();
          new Thread()
          public void run()
               startReciever();
          }.start();
     catch(IOException ioe3)
status.setText("IOException :"+ioe3.getMessage());
//starts a message reciever listening for incomming message
public void startReciever()
mainForm.addCommand(send);
mainForm.append(inTxt);
     mainForm.append(outTxt);
     while(running)
     try
          if(connection.ready())
               int receiveMTU = connection.getReceiveMTU();
                    byte[] data = new byte[receiveMTU];
                    int length = connection.receive(data);
                    String message = new String(data,0,length);
                    inTxt.setString(message);
     catch(IOException ioe4)
     status.setText("IOException :"+ioe4.getMessage());
//sends a message over L2CAP
public void sendMessage()
try
     String message = outTxt.getString();
          byte[] data = message.getBytes();
          int transmitMTU = connection.getTransmitMTU();
          if(data.length <= transmitMTU)
          connection.send(data);
else
          status.setText("message ....");
catch (IOException ioe5)
status.setText("IOException :"+ioe5.getMessage());
//closes L2CAP connection
public void releaseResources()
try
     if(connection != null)
               connection.close();
          if(notifier != null)
               notifier.close();
catch(IOException ioe6)
status.setText("IOException :"+ioe6.getMessage());
import java.util.Vector;
import javax.bluetooth.RemoteDevice;
import javax.bluetooth.DeviceClass;
import javax.bluetooth.DiscoveryListener;
import javax.bluetooth.ServiceRecord;
public class DeviceDiscoverer implements DiscoveryListener
private ChatController controller = null;
private Vector devices = null;
private RemoteDevice[] rDevices = null;
public DeviceDiscoverer(ChatController controller)
super();
this.controller = controller;
     devices = new Vector();
public void deviceDiscovered(RemoteDevice remote,DeviceClass dClass)
devices.addElement(remote);
public void inquiryCompleted(int descType)
     String message = "";
switch(descType)
     case DiscoveryListener.INQUIRY_COMPLETED:
               message = "INQUIRY_COMPLETED";
          break;
     case DiscoveryListener.INQUIRY_TERMINATED:
               message = "INQUIRY_TERMINATED";
          break;
     case DiscoveryListener.INQUIRY_ERROR:
               message = "INQUIRY_ERROR";
          break;
rDevices = new RemoteDevice[devices.size()];
     for(int i=0;i<devices.size();i++)
          rDevices[i] = (RemoteDevice)devices.elementAt(i);
     controller.deviceInquiryFinished(rDevices,message);//call of a method from ChatController class
     devices.removeAllElements();
     controller = null;
devices = null;
public void servicesDiscovered(int transId,ServiceRecord[] services)
public void serviceSearchCompleted(int transId,int respCode)
import javax.bluetooth.RemoteDevice;
import javax.bluetooth.DataElement;
import javax.bluetooth.DeviceClass;
import javax.bluetooth.DiscoveryListener;
import javax.bluetooth.ServiceRecord;
public class ServiceDiscoverer implements DiscoveryListener
private static final String SERVICE_NAME = "L2CAPChat";
private ChatController controller = null;
private ServiceRecord service = null;
public ServiceDiscoverer(ChatController controller)
super();
     this.controller = controller;
public void deviceDiscovered(RemoteDevice remote,DeviceClass dClass)
public void inquiryCompleted(int descType)
public void servicesDiscovered(int transId,ServiceRecord[] services)
for(int j=0;j<services.length;j++)
     DataElement dataElementName = services[j].getAttributeValue(0x0100);
          String serviceName = (String)dataElementName.getValue();
          if(serviceName.equals(SERVICE_NAME))
               service = services[j];
          break;     
public void serviceSearchCompleted(int transId,int respCode)
String message = "";
     switch(respCode)
     case DiscoveryListener.SERVICE_SEARCH_COMPLETED:
               message = "SERVICE_SEARCH_COMPLETED";
          break;
     case DiscoveryListener.SERVICE_SEARCH_ERROR:
               message = "SERVICE_SEARCH_ERROR";
          break;
     case DiscoveryListener.SERVICE_SEARCH_TERMINATED:
               message = "SERVICE_SEARCH_TERMINATED";
          break;
     case DiscoveryListener.SERVICE_SEARCH_NO_RECORDS:
               message = "SERVICE_SEARCH_NO_RECORDS";
          break;
     case DiscoveryListener.SERVICE_SEARCH_DEVICE_NOT_REACHABLE:
               message = "SERVICE_SEARCH_DEVICE_NOT_REACHABLE";
          break;
     controller.serviceSearchFinished(service,message);//calling a method from ChatController class
controller = null;
     service = null;
}