NullPointer Exception on socket.connect() Galaxy Tab 2 running Android 4.04

Question

I seem to be facing this weird error on a socket.connect():

09-18 14:41:22.968: W/System.err(2593): java.lang.NullPointerException
09-18 14:41:22.968: W/Syst         


        

Answer 1

Warning: the code below may be insecure, use at your own risk

In my case I was able to connect using createInsecureRfcommSocketToServiceRecord rather than createRfcommSocketToServiceRecord but I see you were already doing that. My code looks more like this (error/exception checking removed):

BluetoothDevice device;
String deviceName = ... selected or hardcoded device name. See Android HDR sample code
BluetoothDevice[] mAllBondedDevices = (BluetoothDevice[]) mBluetoothAdapter.getBondedDevices().toArray(new BluetoothDevice[0]);

for (BluetoothDevice d : mAllBondedDevices) {
  if (deviceName.equals(d.getName())) {
    device = d;
    break;
  }
}

UUID uuid = device.getUuids()[0].getUuid();
//FAILED: socket = device.createRfcommSocketToServiceRecord(uuid);
// Succeeds: Warning, INSECURE!
socket = device.createInsecureRfcommSocketToServiceRecord(uuid);
socket.connect();
this.dos = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));
this.dis = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
//etc 

Note that while an insecure connection is not perfect, in our case an insecure connection is preferable to no connection. I posted this an an answer so that you could try the alternate code.