Bluetooth Chat HelloWorld

Comments

I have a problem

Hello I've run the code in my NetBeans and I have a problem. I'm not capable to send more than one message and I've tried with con.Close() at Server and at Client. Could you help me please?

// FOR THE SERVER
 public void run(){
        System.out.println("Starting server - please wait...");
try {
 
    //notifier = null;
    //con = null;
 
            local_device = LocalDevice.getLocalDevice();
            System.out.println("SERVER: " + local_device.toString());
 
            DiscoveryAgent disc_agent = local_device.getDiscoveryAgent();
            System.out.println("SERVER: " + disc_agent.toString());
 
            local_device.setDiscoverable(DiscoveryAgent.LIAC);
            String service_UUID = "6";
            deviceName = local_device.getFriendlyName();
            String url = "btl2cap://localhost:" + service_UUID + ";name=" + deviceName;
            System.out.println("SERVER: " + url);
 
            //if (!midlet.connectedServer){
            notifier = (L2CAPConnectionNotifier)Connector.open(url);
           // con = (L2CAPConnection)Connector.open(url);
            //con = (L2CAPConnection)notifier.acceptAndOpen();
            //midlet.connectedServer = true;
            //}
 
            // L2CAPConnectionNotifier notifier = (L2CAPConnectionNotifier)Connector.open(url);
            // con = notifier.acceptAndOpen();
 
            while (listening) {
                con = (L2CAPConnection)notifier.acceptAndOpen(); 
 
 
                if (con.ready()){
                    System.out.println("READY!");
 
                    //midlet.connectedServer = true;
                                        byte[] b = new byte[1000];
                    //
                    System.out.println("1B " + b.toString());
                    //  
                    con.receive(b);
                    //
                    System.out.println("2B " + b.toString());
                    //
                    String s = new String(b, 0, b.length);
 
                    //System.out.println("Received from client: " + s.trim()); 
                    strText = midlet.get_txfSend().getString();
                    mysend(strText);
                    //midlet.get_listInbox().append(s.trim(),null);
                   //listening=false;
 
 
 
//           notifier.close();
//            notifier = null;
//            con = null;
                }
                else
                {
                   // con = notifier.acceptAndOpen();
                    System.out.println("NO ha entrado en el if");
                }
 
                 con.close();
            }
 
        }catch(BluetoothStateException e){System.out.println(e);} catch(IOException f){System.out.println(f);}
    }
 
 
 
 
 // FOR THE CLIENT
 
 public void run() {
        System.out.println("Starting client - please wait...");
        try {
 
            //con = null;
 
            LocalDevice local_device = LocalDevice.getLocalDevice();
            System.out.println("CLIENT: " + local_device.toString());
 
            DiscoveryAgent disc_agent = local_device.getDiscoveryAgent();
            System.out.println("CLIENT: " + disc_agent.toString());
 
            local_device.setDiscoverable(DiscoveryAgent.LIAC);
            inq_listener = new InquiryListener();
            synchronized(inq_listener)	{
                disc_agent.startInquiry(DiscoveryAgent.LIAC, inq_listener);
                try {inq_listener.wait(); }  
                catch(InterruptedException e){}
            }
 
            Enumeration devices = inq_listener.cached_devices.elements();
            System.out.println("CLIENT: " + devices.toString());
 
            UUID[] u = {new UUID( "6", false )};
            int[] attrbs = { 0x0100 };
            serv_listener = new ServiceListener();
            while( devices.hasMoreElements() ) {
                synchronized(serv_listener)	{
                    disc_agent.searchServices(attrbs, u, (RemoteDevice)devices.nextElement(), serv_listener);
                    try {serv_listener.wait();} catch(InterruptedException e){}
                }
            }
        } catch (BluetoothStateException e) {System.out.println(e);}
 
        if (serv_listener.service!=null){
            try {
                String url;
                url = serv_listener.service.getConnectionURL(0, false);
                System.out.println("CLIENT: " + url.toString());
 
                deviceName = LocalDevice.getLocalDevice().getFriendlyName();
                System.out.println("CLIENT: " + deviceName.toString());
 
//                if (!midlet.connectedClient){
//                    con = (L2CAPConnection) Connector.open( url );
//                    con.send("".getBytes());
//                 }
 
               con = (L2CAPConnection) Connector.open( url );
                     con.send("".getBytes()); 
 
                 byte[] b = new byte[1000];
 
                while (listening) {
 
                    if (con.ready()){
                    //    midlet.connectedClient = true;
 
                        con.receive(b);
                        System.out.println(b.toString());
 
                        String s = new String(b, 0, b.length);
                        System.out.println("Received from server: " + s.trim());
 
                        //listening = false;
                        System.out.println("CLIENT: " + s.trim());
 
                       midlet.get_listInbox().append(s.trim(),null);
 
 
 
                     }
 
                }
               con.close();
 
            } catch (IOException g) {System.out.println(g);}
        }
    }

The documentation is different from the code

The first comments says that the file is called BtoothMidlet but the real name is BtoothChat.

/*
 * '''BtoothMidlet'''.java
 *
 * Created on April 18, 2007, 12:39 AM
 */
 
package wiki.nokia.example;
 
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
 
/**
 *
 * @author  Luis Albinati (luis.albinati@gmail.com)
 */
public class '''BtoothChat''' extends MIDlet

problem on send message more than 2 time

Hi i run this code but i have problem , i`m not able to send message more than 2 time ! after 2 time it`s not work ! can any body help me ? thamks

Mulyawan - need help

could u help me? i want to read some data via bluetooth connection on mobile phone (J2ME). the data transmitted using bluetooth module serial port profile (SPP).

how can i read the data?

mulyawan 12:19, 3 November 2011 (EET)

Hamishwillee - Mulyawan - this was written in 2007

Hi @Mulyawan

This article was written in 2007 and it is quite possible the author is no longer reviewing it (although their email is in the code so you could email them directly). Unless your question is directly related to the article and code in question, I suggest you instead post your query on the Java ME discussion boards as this will increase the number of people who see it: http://www.developer.nokia.com/Community/Discussion/forumdisplay.php?3-Mobile-Java

Regards

Hamish

hamishwillee 05:49, 4 November 2011 (EET)

Log in or Join to leave comments.

Article Metadata

---

Article

Created: luis-junior (18 Apr 2007)

Last edited: hamishwillee (17 Jun 2013)

Bluetooth HelloWorld (Chat example)

This Java ME Bluetooth chat example enables server-client communication over L2CAP protocol. It is separated in 3 classes: a main midlet to start application, a Bluetooth Server class and a Bluetooth Client class.

---

The midlet: BtoothChat.java

/*
 * BtoothMidlet.java
 *
 * Created on April 18, 2007, 12:39 AM
 */
 
package wiki.nokia.example;
 
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
 
/**
 *
 * @author  Luis Albinati (luis.albinati@gmail.com)
 */
public class BtoothChat extends MIDlet implements CommandListener {
 
    private Display display;
    private List list;
 
 
    public BtoothChat() {
 
        display = Display.getDisplay(this);
        list = new List("Select", List.EXCLUSIVE);
        list.append("Server", null);
        list.append("Client", null);
 
        Command cmd_ok = new Command("OK", Command.OK, 1);
 
        list.addCommand(cmd_ok);
        list.setCommandListener(this);
    }
 
    public void startApp() {
        display.setCurrent(list);
    }
 
    public void pauseApp() {
    }
 
    public void destroyApp(boolean unconditional) {
    }
 
    public void commandAction(Command command, Displayable d) {
 
        if (command.getCommandType()==Command.OK) {
            switch (list.getSelectedIndex()){
                case 0: {
 
                    new BluetoothServer(this); //starting instance of a server
 
                    break;
                }
 
                case 1: {
 
                    new BluetoothClient(this); //starting instance of a client
 
                    break;
                }
            }
        }
 
    }
    protected void setAlert(String info) {
        Alert a = new Alert("INFO");
        a.setString(info);
        a.setTimeout(Alert.FOREVER);
        display.setCurrent(a);
    }
}

---

The server class: BluetoothServer.java

/*
 * BluetoothServer.java
 *
 * Created on April 18, 2007, 12:45 AM
 *
 */
 
package wiki.nokia.example;
 
import java.io.IOException;
import javax.bluetooth.BluetoothStateException;
import javax.bluetooth.DiscoveryAgent;
import javax.bluetooth.L2CAPConnection;
import javax.bluetooth.L2CAPConnectionNotifier;
import javax.bluetooth.LocalDevice;
import javax.microedition.io.Connector;
 
/**
 *
 * @author Luis Albinati (luis.albinati@gmail.com)
 */
public class BluetoothServer implements Runnable {
 
    private boolean listening = true;
    private LocalDevice local_device;
    private BtoothChat midlet;
    private String deviceName;
    private L2CAPConnection con;
 
    /** Creates a new instance of BluetoothServer */
    public BluetoothServer(BtoothChat midlet) {
        this.midlet = midlet;
        Thread t = new Thread(this);
        t.start();
    }
 
    public void run(){
        System.out.println("Starting server - please wait...");
 
        try {
            local_device = LocalDevice.getLocalDevice();
            DiscoveryAgent disc_agent = local_device.getDiscoveryAgent();
            local_device.setDiscoverable(DiscoveryAgent.LIAC);
            String service_UUID = "00000000000010008000006057028A06";
            deviceName = local_device.getFriendlyName();
            String url = "btl2cap://localhost:" + service_UUID + ";name=" + deviceName;
 
            L2CAPConnectionNotifier notifier = (L2CAPConnectionNotifier)Connector.open(url);
            con = notifier.acceptAndOpen();
 
            while (listening) {
                if (con.ready()){
                    byte[] b = new byte[1000];
                    con.receive(b);
                    String s = new String(b, 0, b.length);
                    System.out.println("Recieved from client: " + s.trim());
                    midlet.setAlert(s.trim());
                    send("Hello client, my name is: " + getName());
                    listening=false;
                }
            }
 
        } catch(BluetoothStateException e){System.out.println(e);} catch(IOException f){System.out.println(f);}
    }
    private void send(String s){
        byte[] b = s.getBytes();
        try {
            con.send(b);
        } catch(IOException e){
            System.out.println(e);
        }
    }
    private String getName(){
        return deviceName;
    }
}

---

The client class: BluetoothClient.java

/*
 * BluetoothClient.java
 *
 * Created on April 18, 2007, 12:45 AM
 *
 */
 
package wiki.nokia.example;
 
import java.io.IOException;
import java.util.Enumeration;
import java.util.Vector;
import javax.bluetooth.BluetoothStateException;
import javax.bluetooth.DeviceClass;
import javax.bluetooth.DiscoveryAgent;
import javax.bluetooth.DiscoveryListener;
import javax.bluetooth.L2CAPConnection;
import javax.bluetooth.LocalDevice;
import javax.bluetooth.RemoteDevice;
import javax.bluetooth.ServiceRecord;
import javax.bluetooth.UUID;
import javax.microedition.io.Connector;
 
/**
 *
 * @author  Luis Albinati (luis.albinati@gmail.com)
 */
public class BluetoothClient implements Runnable {
 
    private InquiryListener inq_listener;
    private ServiceListener serv_listener;
    private boolean listening = true;
    private BtoothChat midlet;
    private String deviceName;
    private L2CAPConnection con;
 
    /** Creates a new instance of BluetoothClient */
    public BluetoothClient(BtoothChat midlet){
        this.midlet = midlet;
        Thread t = new Thread(this);
        t.start();
    }
    public void run() {
        System.out.println("Starting client - please wait...");
        try {
            LocalDevice local_device = LocalDevice.getLocalDevice();
            DiscoveryAgent disc_agent = local_device.getDiscoveryAgent();
            local_device.setDiscoverable(DiscoveryAgent.LIAC);
            inq_listener = new InquiryListener();
            synchronized(inq_listener)	{
                disc_agent.startInquiry(DiscoveryAgent.LIAC, inq_listener);
                try {inq_listener.wait(); }  catch(InterruptedException e){}
            }
 
            Enumeration devices = inq_listener.cached_devices.elements();
 
            UUID[] u = new UUID[]{new UUID( "00000000000010008000006057028A06", false )};
            int attrbs[] = { 0x0100 };
            serv_listener = new ServiceListener();
            while( devices.hasMoreElements() ) {
                synchronized(serv_listener)	{
                    disc_agent.searchServices(attrbs, u, (RemoteDevice)devices.nextElement(), serv_listener);
                    try {serv_listener.wait();} catch(InterruptedException e){}
                }
            }
        } catch (BluetoothStateException e) {System.out.println(e);}
 
        if (serv_listener.service!=null){
            try {
                String url;
                url = serv_listener.service.getConnectionURL(0, false);
                deviceName = LocalDevice.getLocalDevice().getFriendlyName();
                con = (L2CAPConnection) Connector.open( url );
                send("Hello server, my name is: " + getName());
 
                byte[] b = new byte[1000];
                while (listening) {
                    if (con.ready()){
                        con.receive(b);
                        String s = new String(b, 0, b.length);
                        System.out.println("Received from server: " + s.trim());
                        midlet.setAlert(s.trim());
                        listening = false;
                    }
                }
            } catch (IOException g) {System.out.println(g);}
        }
    }
    private void send(String s){
        byte[] b = s.getBytes();
        try {
            con.send(b);
        } catch(IOException e){
            System.out.println(e);
        }
    }
    private String getName(){
        return deviceName;
    }
}
class InquiryListener implements DiscoveryListener {
    public Vector cached_devices;
    public InquiryListener() {
        cached_devices = new Vector();
    }
 
    public void deviceDiscovered( RemoteDevice btDevice, DeviceClass cod )	{
        int major = cod.getMajorDeviceClass();
        if( ! cached_devices.contains( btDevice ) )	{
            cached_devices.addElement( btDevice );
        }
    }
 
    public void inquiryCompleted( int discType )	{
        synchronized(this){	this.notify(); }
    }
 
    public void servicesDiscovered( int transID, ServiceRecord[] servRecord )	{}
    public void serviceSearchCompleted( int transID, int respCode )	{}
}
 
class ServiceListener	implements DiscoveryListener	{
    public ServiceRecord service;
    public ServiceListener()	{	}
 
    public void servicesDiscovered( int transID, ServiceRecord[] servRecord )	{
        service = servRecord[0];
        System.out.println("foundService");
    }
 
    public void serviceSearchCompleted( int transID, int respCode )	{
        synchronized( this ){	this.notify();}
    }
 
    public void deviceDiscovered( RemoteDevice btDevice, DeviceClass cod ){}
    public void inquiryCompleted( int discType ){}
}