CODEWITHSUNDEEP
javaandroidsocketsbluetooth
Carling Knight
Carling Knight

Reputation: 495

BluetoothSocket Connect() throws IOException read failed, socket might closed

So I'm trying to connect an Android app to a raspberry Pi, the devices are paired and are trusted by I receive an error identical to the one found here: IOException: read failed, socket might closed - Bluetooth on Android 4.3

However that solution seems really messy and I'm not even sure how to integrate it with my current code. So here's my current code:

 @Override
    protected void onHandleIntent(Intent intent) {
        device = (BluetoothDevice) intent.getExtras().get("device");

        if (device != null) {
            Log.v("DeviceManager", "Beginning attempts to communicate to: " + device.getName());
            try {
                BluetoothSocket socket = device.createRfcommSocketToServiceRecord(MY_UUID);
                //Throws exception here:
                socket.connect();
                outputStream = socket.getOutputStream();
                inputStream = socket.getInputStream();

                while (Utils.appIsInForeground && device != null) {
                    if (outputStream == null){
                        Log.e("DeviceManager", "Looks like the outputStream is null...");
                        if (inputStream == null){
                            Log.e("DeviceManager", "And input stream is null, are you even connected to the device?");
                        }else{
                            Log.e("DeviceManager", "Although strangely, input stream has been set.");
                        }
                    }else{
                        String myString = "This is a string!";
                        byte[] myByteArray = myString.getBytes("UTF-8");
                        outputStream.write(myByteArray, 0, myByteArray.length);
                    }
                    Thread.sleep(1000);
                }

            } catch (IOException e) {
                e.printStackTrace();
                Log.e("DeviceManager", "Can't create a socket to the bluetooth device.");
            } catch (InterruptedException e) {
                e.printStackTrace();
                Log.e("DeviceManager", "The sleep thread was interrupted.");
            } catch (NullPointerException e) {
                e.printStackTrace();
                Log.e("DeviceManager", "A null pointer exception, this is probably not good.");
            }
        }else {
            Log.e("DeviceManager", "The Device Manager has been passed a null object instead of a device.");
        }
    }

And this is the stack trace I'm getting:

03-26 11:44:09.525 7916-8048/com.app.name W/System.err: java.io.IOException: read failed, socket might closed or timeout, read ret: -1
03-26 11:44:09.526 7916-8048/com.app.name W/System.err:     at android.bluetooth.BluetoothSocket.readAll(BluetoothSocket.java:685)
03-26 11:44:09.527 7916-8048/com.app.name W/System.err:     at android.bluetooth.BluetoothSocket.readInt(BluetoothSocket.java:697)
03-26 11:44:09.527 7916-8048/com.app.name W/System.err:     at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:374)
03-26 11:44:09.527 7916-8048/com.app.name W/System.err:     at com.app.name.service.DeviceManager.onHandleIntent(DeviceManager.java:60)
03-26 11:44:09.527 7916-8048/com.app.name W/System.err:     at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:67)
03-26 11:44:09.528 7916-8048/com.app.name W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:102)
03-26 11:44:09.528 7916-8048/com.app.name W/System.err:     at android.os.Looper.loop(Looper.java:154)
03-26 11:44:09.528 7916-8048/com.app.name W/System.err:     at android.os.HandlerThread.run(HandlerThread.java:61)
03-26 11:44:09.528 7916-8048/com.app.name E/DeviceManager: Can't create a socket to the bluetooth device.

What's strange is that my Raspberry Pi comes up on BluetoothCtl saying that the phone connected but then it immediately disconnects.

Upvotes: 0

Views: 1116

Answers (1)

vookimedlo
vookimedlo

Reputation: 1378

Connection would be created just for the querying the SDP database on your Raspberry board.

1) Check if the SDP on the Raspberry side really contains the requested MY_UUID record

2) It's not obvious if the Raspberry board is bonded with your Android. It's required because the you creates a secure socket in the code you posted.

  • You could try the insecure version which do not require to have a bonded device: createInsecureRfcommSocketToServiceRecord

Upvotes: 0

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