Pfthb

I am having trouble connecting to the client socket using Android's Bluetooth API. I have already read this post and all of the related posts mentioned within. I am using the same UUID for the client and the server. The server bluetoothSocket.connect() times out each time, and throws the exception
java.io.IOException: read failed, socket might closed or timeout, read ret: -1. I'm not sure that I'm doing wrong in this case. I've been reading the Android Bluetooth API documentation and Chat application code samples and what I'm trying to do is quite similar. I have tried unpairing and pairing again, to no avail.

Here is the client code, running as part of an application on a OnePlus A3003, Android 7.1.1:

public class BluetoothTrafficLightConnectThread extends Thread 
 private BluetoothDevice bluetoothDevice;
 private BluetoothSocket bluetoothSocket;

 public BluetoothTrafficLightConnectThread(BluetoothDevice btDevice)
 BluetoothSocket tmp = null;
 bluetoothDevice = btDevice;
 boolean temp = btDevice.fetchUuidsWithSdp();
 UUID uuid = null;

 if(temp)
 uuid = btDevice.getUuids()[0].getUuid();
 

 Log.i(tag, "SmartRide using UUID " + uuid);

 try
 //MY_UUID is the app's UUID string, also used by the server code
 tmp = bluetoothDevice.createRfcommSocketToServiceRecord(uuid);
 
 catch(IOException e)
 Log.i(tag, "Get socket failed in BluetoothTrafficLightConnectThread");
 

 bluetoothSocket = tmp;
 

 public void run()

 try 
 // Connect the device through the socket. This will block
 // until it succeeds or throws an exception
 bluetoothSocket.connect();
 Log.i(tag, "TrafficLightConnect succeeded.");
 
 catch (IOException connectException) 
 Log.i(tag, "TrafficLightConnect failed.n" + connectException.toString());

 try 
 bluetoothSocket.close();
 
 catch (IOException closeException) 
 Log.i(tag, "Failed to close socket after connection unsuccessful." + closeException);
 
 return;
 

 // Do work to manage the connection (in a separate thread)
 mHandler.obtainMessage(SUCCESS_CONNECT_TRAFFIC_LIGHT, bluetoothSocket).sendToTarget();
 

 public void cancel()
 try 
 bluetoothSocket.close();
 
 catch (IOException e) 
 

And the server code, running on a Samsung J5, Android version 8.1.0:

private class AcceptThread extends Thread 
 // The local server socket - listens for incoming requests
 private final BluetoothServerSocket mmServerSocket;
 private String mSocketType;

 public AcceptThread(boolean secure)
 BluetoothServerSocket tmp = null;
 mSocketType = secure ? "Secure" : "Insecure";

 Log.d(TAG, "AcceptThread constructor");

 // Create a new listening server socket
 try
 if(secure) 
 tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE, MY_UUID);

 Log.d(TAG, "Have a secure rfcomm socket. " + tmp.toString());
 Log.d(TAG, "TrafficLight using UUID " + MY_UUID.toString());
 
 else 
 tmp = mAdapter.listenUsingInsecureRfcommWithServiceRecord(NAME_INSECURE, MY_UUID);
 Log.d(TAG, "Have an insecure rfcomm socket." + tmp.toString());
 

 catch (IOException e) 
 Log.e(TAG, "Socket type: " + mSocketType + "listen() failed", e);
 

 mmServerSocket = tmp;
 mState = STATE_LISTEN;

 updateUserInterfaceTitle();
 

 @Override
 public void run()
 Log.d(TAG, "Begin acceptThread");
 setName("AcceptThread" + mSocketType);

 BluetoothSocket socket = null;

 while(mState != STATE_CONNECTED)
 try
 // This is a blocking call and will only return on a
 // successful connection or an exception
 Log.d(TAG, "Trying to connect to the remote device.");
 socket = mmServerSocket.accept();
 mmServerSocket.close();
 Log.d(TAG, "Accepted the incoming connection request.");
 catch(IOException e)
 Log.e(TAG, "Socket Type: " + mSocketType + ", .accept() failed", e);
 break;
 

 // Connection was accepted
 if(socket != null)
 synchronized(BluetoothTLService.this)
 switch(mState)
 case STATE_LISTEN:
 Log.d(TAG, "Connection established.");
 // Can terminate the AcceptThread as we are now connected
 // Should notify others that we are ready to send data now
 mIsConnected = true;
 setUpConnection(socket, socket.getRemoteDevice(), mSocketType);
 break;
 case STATE_NONE:
 case STATE_CONNECTED:
 // Either not ready or already connected. Terminate new socket
 try
 socket.close();
 Log.d(TAG, "Closing socket.");
 catch(IOException e)
 Log.e(TAG, "Could not close unwanted socket", e);
 
 break;
 
 
 
 

 Log.d(TAG, "END mAcceptThread, socket Type: " + mSocketType);
 

 public void cancel()
 Log.d(TAG, "Socket Type" + mSocketType + "cancel " + this);
 try 
 mmServerSocket.close();
 catch (IOException e) 
 Log.e(TAG, "Socket Type" + mSocketType + "close() of server failed", e);