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Buetooth connection failed: read failed, socket might closed or timeout, read ret: -1

I am trying to create a Bluetooth connection.

I can search for nearby devices but when I try to connect I get an error I do not understand:


01-03 00:55:06.909 6654-6654/com.bluetooth.prova3.listdiscovery D/CONNECTTHREAD: Could not close read failed, socket might closed or timeout, read ret: -1

I Have two classes for connect, one that receives the device and execute the connection, an other for make connection.


package com.bluetooth.prova3.listdiscovery;


public class ConexionActivity extends AppCompatActivity {

    protected void onCreate(Bundle savedInstanceState) {

        //Aqui rebo el dispositiu que he seleccionat per conectarme
        Intent intent = getIntent();
        BluetoothDevice bluetoothDevice = intent.getExtras().getParcelable("btdevice");
        //mostro el nom per la pantalla amb un text view
        TextView MacAddress = (TextView)findViewById(;
        String aaaa = bluetoothDevice.getName() + "n" + bluetoothDevice.getAddress();

        ConnectThread conexion = new ConnectThread(bluetoothDevice);;

package com.bluetooth.prova3.listdiscovery;


public class ConnectThread extends Thread{
    private final BluetoothSocket mmSocket;
    private final BluetoothDevice mmDevice;
    UUID UUIDaleatorio = UUID.randomUUID();
    public ConnectThread(BluetoothDevice device) {
        // Use a temporary object that is later assigned to mmSocket,
        // because mmSocket is final
        BluetoothSocket tmp = null;
        mmDevice = device;

        // Get a BluetoothSocket to connect with the given BluetoothDevice
        try {
            // MY_UUID is the app's UUID string, also used by the server code
            tmp = device.createRfcommSocketToServiceRecord(UUIDaleatorio);
        } catch (IOException e) {

            Log.d("CONNECTTHREAD", "Could not close connection:" + e.toString());
        mmSocket = tmp;

    public void run() {
        // Cancel discovery because it will slow down the connection
       try {
            // Connect the device through the socket. This will block
            // until it succeeds or throws an exception
        } catch (IOException connectException) {
           Log.d("CONNECTTHREAD", "Could not close connection:" + connectException.toString());
            // Unable to connect; close the socket and get out
            try {
            } catch (IOException closeException) { Log.d("CONNECTTHREAD", "Could not close connection:" + closeException.toString());}

        // Do work to manage the connection (in a separate thread)
       // manageConnectedSocket(mmSocket);

    /** Will cancel an in-progress connection, and close the socket */
    public void cancel() {
        try {
        } catch (IOException e) { }


Try to use ,


in place of


This should fix the problem. Share your debugging results , if this doesn’t fix the issue.

Also , don’t generate random UUID(s), try the one below.

UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");