UUID bluetooth and android devices

Question

I'm trying to develop an application for Android devices that connects two devices, but the problem is that I can only connect (using Bluetooth) with PC Bluetooth or devices with another OS than Android.

I think that the problem is the UUID, right now I'm using, in BluetoothCommandService.java:

private static final 
        UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");

And then:

    private class ConnectThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final BluetoothDevice mmDevice;

    public ConnectThread(BluetoothDevice device) {
        mmDevice = device;
        BluetoothSocket tmp = null;

        // Get a BluetoothSocket for a connection with the
        // given BluetoothDevice
        try {
            tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
        } catch (IOException e) {
            Log.e(LOG_TAG, "create() failed", e);
        }
        mmSocket = tmp;
    }

Anyway i leave here all the code related to BluetoothCommandService.java:

    package com.example.vista;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.telephony.TelephonyManager;
import android.util.Log;

public class BluetoothCommandService {
    // Debugging
    private static final String LOG_TAG = "BluetoothCommandService";
    private static final boolean DEBUG = true;

    // Unique UUID for this application
    private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");

    /*TelephonyManager tManager = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
    String uuid = tManager.getDeviceId();*/


    // Member fields
    private final BluetoothAdapter mAdapter;
    private final Handler mHandler;
    private ConnectThread mConnectThread;
    private ConnectedThread mConnectedThread;
    private int mState;
//    private BluetoothDevice mSavedDevice;
//    private int mConnectionLostCount;

    // Constants that indicate the current connection state
    public static final int STATE_NONE = 0;       // we're doing nothing
    public static final int STATE_LISTEN = 1;     // now listening for incoming connections
    public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection
    public static final int STATE_CONNECTED = 3;  // now connected to a remote device

    // Constants that indicate command to computer
    public static final int EXIT_CMD = -1;
    public static final int VOL_UP = 1;
    public static final int VOL_DOWN = 2;
    public static final int MOUSE_MOVE = 3;

    /**
     * Constructor. Prepares a new BluetoothChat session.
     * @param context  The UI Activity Context
     * @param handler  A Handler to send messages back to the UI Activity
     */
    public BluetoothCommandService(Context context, Handler handler) {
        if (DEBUG) Log.e(LOG_TAG, "BluetoothCommandService");
        mAdapter = BluetoothAdapter.getDefaultAdapter();
        mState = STATE_NONE;
        //mConnectionLostCount = 0;
        mHandler = handler;
    }

    /**
     * Set the current state of the chat connection
     * @param state  An integer defining the current connection state
     */
    private synchronized void setState(int state) {
        if (DEBUG) Log.e(LOG_TAG, "setState() " + mState + " -> " + state);
        mState = state;

        // Give the new state to the Handler so the UI Activity can update
        mHandler.obtainMessage(Buscarpartida.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
    }

    /**
     * Return the current connection state. */
    public synchronized int getState() {
        Log.e(LOG_TAG, "MSTATE "+ mState);
        return mState;
    }

    /**
     * Start the chat service. Specifically start AcceptThread to begin a
     * session in listening (server) mode. Called by the Activity onResume() */
    public synchronized void start() {
        if (DEBUG) Log.e(LOG_TAG, "start");

        // Cancel any thread attempting to make a connection
        if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}


        setState(STATE_NONE);
        Log.e(LOG_TAG, "start fin "+ mState);
    }

    /**
     * Start the ConnectThread to initiate a connection to a remote device.
     * @param device  The BluetoothDevice to connect
     */
    public synchronized void connect(BluetoothDevice device) {
        if (DEBUG) Log.e(LOG_TAG, "connect to: " + device);

        // Cancel any thread attempting to make a connection
        if (mState == STATE_CONNECTING) {
            if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}
        }

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}

        // Start the thread to connect with the given device
        mConnectThread = new ConnectThread(device);
        mConnectThread.start();

        setState(STATE_CONNECTING);
    }

    /**
     * Start the ConnectedThread to begin managing a Bluetooth connection
     * @param socket  The BluetoothSocket on which the connection was made
     * @param device  The BluetoothDevice that has been connected
     */
    public synchronized void connected(BluetoothSocket socket, BluetoothDevice device) {
        // Cancel the thread that completed the connection
        if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}

        // Start the thread to manage the connection and perform transmissions
        mConnectedThread = new ConnectedThread(socket);
        mConnectedThread.start();

        // Send the name of the connected device back to the UI Activity
        Message msg = mHandler.obtainMessage(Buscarpartida.MESSAGE_DEVICE_NAME);
        Bundle bundle = new Bundle();
        bundle.putString(Buscarpartida.DEVICE_NAME, device.getName());
        msg.setData(bundle);
        mHandler.sendMessage(msg);



        setState(STATE_CONNECTED);
    }

    /**
     * Stop all threads
     */
    public synchronized void stop() {
        if (DEBUG) Log.e(LOG_TAG, "stop");
        if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}
        if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}

        setState(STATE_NONE);
        if (DEBUG) Log.e(LOG_TAG, "stop fin "+ mState);
    }

    /**
     * Write to the ConnectedThread in an unsynchronized manner
     * @param out The bytes to write
     * @see ConnectedThread#write(byte[])
     */
    public void write(byte[] out) {
        // Create temporary object
        ConnectedThread r;
        // Synchronize a copy of the ConnectedThread
        synchronized (this) {
            if (mState != STATE_CONNECTED) return;
            r = mConnectedThread;
        }
        // Perform the write unsynchronized
        r.write(out);
    }

    public void write(int out) {
        // Create temporary object
        ConnectedThread r;
        // Synchronize a copy of the ConnectedThread
        synchronized (this) {
            if (mState != STATE_CONNECTED) return;
            r = mConnectedThread;
        }
        // Perform the write unsynchronized
        r.write(out);
    }

    /**
     * Indicate that the connection attempt failed and notify the UI Activity.
     */
    private void connectionFailed() {
        setState(STATE_LISTEN);

        // Send a failure message back to the Activity
        Message msg = mHandler.obtainMessage(Buscarpartida.MESSAGE_TOAST);
        Bundle bundle = new Bundle();
        bundle.putString(Buscarpartida.TOAST, "Imposible Conectar");
        msg.setData(bundle);
        mHandler.sendMessage(msg);
    }

    /**
     * Indicate that the connection was lost and notify the UI Activity.
     */
    private void connectionLost() {
//        mConnectionLostCount++;
//        if (mConnectionLostCount < 3) {
//          // Send a reconnect message back to the Activity
//          Message msg = mHandler.obtainMessage(Main.MESSAGE_TOAST);
//          Bundle bundle = new Bundle();
//          bundle.putString(Main.TOAST, "Device connection was lost. Reconnecting...");
//          msg.setData(bundle);
//          mHandler.sendMessage(msg);
//          
//          connect(mSavedDevice);      
//        } else {
            setState(STATE_LISTEN);
            // Send a failure message back to the Activity
            Message msg = mHandler.obtainMessage(Buscarpartida.MESSAGE_TOAST);
            Bundle bundle = new Bundle();
            bundle.putString(Buscarpartida.TOAST, "Conexion Perdida");
            msg.setData(bundle);
            mHandler.sendMessage(msg);
//        }
    }

    /**
     * This thread runs while attempting to make an outgoing connection
     * with a device. It runs straight through; the connection either
     * succeeds or fails.
     */
    private class ConnectThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;

        public ConnectThread(BluetoothDevice device) {
            mmDevice = device;
            BluetoothSocket tmp = null;

            // Get a BluetoothSocket for a connection with the
            // given BluetoothDevice
            try {
                tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
            } catch (IOException e) {
                Log.e(LOG_TAG, "create() failed", e);
            }
            mmSocket = tmp;
        }

        public void run() {
            setName("ConnectThread");

            // Always cancel discovery because it will slow down a connection
            mAdapter.cancelDiscovery();
            Log.e(LOG_TAG, "cancelDiscovery()");
            // Make a connection to the BluetoothSocket
            try {
                // This is a blocking call and will only return on a
                // successful connection or an exception

                mmSocket.connect();
                Log.e(LOG_TAG, "mmSocket.connect()");

            } catch (IOException e) {
                connectionFailed();
                Log.e(LOG_TAG, " connectionFailed()");
                // Close the socket
                try {
                    mmSocket.close();
                } catch (IOException e2) {
                    Log.e(LOG_TAG, "unable to close() socket during connection failure", e2);
                }
                // Start the service over to restart listening mode
                Log.e(LOG_TAG, "run2()");
                BluetoothCommandService.this.start();

                return;
            }

            // Reset the ConnectThread because we're done
            synchronized (BluetoothCommandService.this) {
                mConnectThread = null;
            }

            // Start the connected thread
            connected(mmSocket, mmDevice);
        }

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
                Log.e(LOG_TAG, "close() of connect socket failed", e);
            }
        }
    }

    /**
     * This thread runs during a connection with a remote device.
     * It handles all incoming and outgoing transmissions.
     */
    private class ConnectedThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;

        public ConnectedThread(BluetoothSocket socket) {
            Log.e(LOG_TAG, "create ConnectedThread");
            mmSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            // Get the BluetoothSocket input and output streams
            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {
                Log.e(LOG_TAG, "temp sockets not created", e);
            }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;
        }

        public void run() {
            Log.e(LOG_TAG, "runrer");
            byte[] buffer = new byte[1024];

            // Keep listening to the InputStream while connected
            while (true) {
                try {
                    // Read from the InputStream
                    int bytes = mmInStream.read(buffer);

                    // Send the obtained bytes to the UI Activity
                    mHandler.obtainMessage(Buscarpartida.MESSAGE_READ, bytes, -1, buffer)
                            .sendToTarget();
                } catch (IOException e) {
                    Log.e(LOG_TAG, "disconnected", e);
                    connectionLost();
                    break;
                }
            }
        }


        /**
         * Write to the connected OutStream.
         * @param buffer  The bytes to write
         */
        public void write(byte[] buffer) {
            try {
                mmOutStream.write(buffer);

                // Share the sent message back to the UI Activity
//                mHandler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer)
//                        .sendToTarget();
            } catch (IOException e) {
                Log.e(LOG_TAG, "Exception during write", e);
            }
        }

        public void write(int out) {
            try {
                mmOutStream.write(out);

                // Share the sent message back to the UI Activity
//                mHandler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer)
//                        .sendToTarget();
            } catch (IOException e) {
                Log.e(LOG_TAG, "Exception during write", e);
            }
        }

        public void cancel() {
            try {
                mmOutStream.write(EXIT_CMD);
                mmSocket.close();
            } catch (IOException e) {
                Log.e(LOG_TAG, "close() of connect socket failed", e);
            }
        }
    }
}

Thank you very much!

Solution

Why would you think that:

private static final 
    UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");

is a UUID (Universally Unique ID)?

You now have all your devices using this code with the same UUID. You need to get a better UUID ....

Check out this question (and it's answers): How can I get the UUID of my Android phone in an application?

Comments

[rolfl]

Check ALL the answers (the not-accepted answer is the better one)

[Admin]

Ok, thank you very much, you answer helps me a lot. l I wish I can fix it soon :D

[Anshad Rasheed]

did you fixed it?