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PO"Service discovery failed" from Android Bluetooth Insecure Rfcomm
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copied!<p><strong>Does anyone know how to create an insecure RFCOMM connection between 2 Android devices at API level 2.3.3 while using an arbitrarily declared service name?</strong> (not random or changing service name, just a service name that I define myself)</p> <h2>Details</h2> <p>I am trying to create an insecure Rfcomm connection between 2 Android devices: Droid X2 and an Asus Transformer. I am assuming that both of these devices have functionality at the level of Android 2.3.3 to actually gain the ability to use insecure Rfcomm.</p> <p>When I try to create the Bluetooth connection as described <a href="https://stackoverflow.com/questions/5308373/how-to-create-insecure-rfcomm-socket-in-android">here</a>, using the now public createInsecureRfcommSocketToServiceRecord() and listenUsingInsecureRfcommWithServiceRecord(SERVICE, UUID), I get a reported:</p> <pre><code>java.io.IOException: Service discovery failed at android.bluetooth.BluetoothSocket$SdpHelper.doSdp(BluetoothSocket.java:377) at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:201) at com.s4d.bluenomad.DeviceConnections$ClientThread.run(DeviceConnections.java:406) </code></pre> <p>I found a <a href="https://stackoverflow.com/questions/8282481/android-bluetooth-connection-secure-insecure">related question</a> where someone creating a normal connection was getting this error and used reflection to invoke a private method. However, I have no idea what private method would now correspond to initiating an "insecure" connection. I tried using the solution proposed in that related question, but I am asked by Android to pair the devices which is exactly what I need to avoid. I really do need the insecure approach.</p> <p>I even tried a combination of the official and hacked solutions outlined <a href="https://stackoverflow.com/questions/8282481/android-bluetooth-connection-secure-insecure">here</a></p> <h2>Relevant Code Snippets</h2> <p><strong>Creating ServerThread To Listen For Connections</strong></p> <pre><code>Log.i(TAG, "Constructing a ServerThread"); // Use a temporary object that is later assigned to serverSocket, // because serverSocket is final BluetoothServerSocket tmp = null; try { // MY_UUID is the app's UUID string, also used by the client code tmp = btAdapter.listenUsingInsecureRfcommWithServiceRecord(SERVICE_NAME, SERVICE_UUID); Log.i(TAG,"Started listening on insecure RFCOMM channel for service requests for: " + SERVICE_NAME); } catch (IOException e) { } serverSocket = tmp; </code></pre> <p><strong>ServerThread Listening for Connections</strong></p> <pre><code>BluetoothSocket socket; while(true) { try { socket = serverSocket.accept(); } catch( IOException e) { break; } if( socket != null ) { Log.i(TAG, "Received new socket connection requesting service: " + SERVICE_NAME); } else { Log.i(TAG, "Socket connection attempted, but socket received is NULL."); } } </code></pre> <p><strong>Creating ClientThread to Initiate Connections</strong></p> <pre><code>Log.i(TAG, "Constructing a ClientThread"); BluetoothSocket tmp = null; try { // MY_UUID is the app's UUID string, also used by the server code tmp = device.createInsecureRfcommSocketToServiceRecord(SERVICE_UUID); Log.i(TAG,"Created client socket on insecure RFCOMM channel for service requests for: " + SERVICE_NAME); } catch (IOException e) { Log.i(TAG, "Failed to createInsecureRfcommSocket() against MAC: " + device.getAddress()); } clientSocket = tmp; </code></pre> <p><strong>ClientThread Connecting to Server</strong></p> <pre><code>try { clientSocket.connect(); } catch( final IOException e) { DeviceConnections.this.runOnUiThread(new Runnable() { @Override public void run() { console.append("Client unable to connect to service."); Log.i(TAG, "Client socket unable to connect() to: " + clientSocket.getRemoteDevice().getAddress()); e.printStackTrace(); } }); } </code></pre> <p>I do get the log output "Client socket unable to connect() to: [MY_MAC_ADDRESS]", then I get the stacktrace for the "Service discovery failed" exception.</p>

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