UndeliverableException thrown within a RxAndroidBle stream

Question

I have a misbehaving BLE device (temp sensor) that keeps throwing a status 8 (GATT_INSUF_AUTHORIZATION or GATT_CONN_TIMEOUT) exception everytime i try to connect to the device. I'm not concerned about this exception as the device is faulty.

However, I keep getting notified that i've not handled the error correctly by rxjava2 when using RxAndroidBle(1.9.1); see here;

This is my code.

 rxBleClient
                .getBleDevice(macAddress)
                .establishConnection(false)
                .flatMapSingle { it.readRssi() }
                .subscribe({ "test1:Success" }, { "test1:error" })

and the Error

   I/RxBle#GattCallback: MAC='E9:CF:8A:D0:01:19'  onConnectionStateChange(), status=8, value=0
D/RxBle#ClientOperationQueue: FINISHED ConnectOperation(147547253) in 10257 ms
D/RxBle#ConnectionOperationQueue: Connection operations queue to be terminated (MAC='E9:CF:8A:D0:01:19')
    com.polidea.rxandroidble2.exceptions.BleDisconnectedException: Disconnected from MAC='E9:CF:8A:D0:01:19' with status 8 (GATT_INSUF_AUTHORIZATION or GATT_CONN_TIMEOUT)
        at com.polidea.rxandroidble2.internal.connection.RxBleGattCallback$2.onConnectionStateChange(RxBleGattCallback.java:77)
        at android.bluetooth.BluetoothGatt$1$4.run(BluetoothGatt.java:249)
        at android.bluetooth.BluetoothGatt.runOrQueueCallback(BluetoothGatt.java:725)
        at android.bluetooth.BluetoothGatt.-wrap0(Unknown Source:0)
        at android.bluetooth.BluetoothGatt$1.onClientConnectionState(BluetoothGatt.java:244)
        at android.bluetooth.IBluetoothGattCallback$Stub.onTransact(IBluetoothGattCallback.java:70)
        at android.os.Binder.execTransact(Binder.java:697)
D/BleDeviceManagerNew$observeRssiTest: test1:error
E/plication$setupApp: Terminal Exception From RXJAVA was Not handled correctly
    io.reactivex.exceptions.UndeliverableException: The exception could not be delivered to the consumer because it has already canceled/disposed the flow or the exception has nowhere to go to begin with. Further reading: https://github.com/ReactiveX/RxJava/wiki/What's-different-in-2.0#error-handling | com.polidea.rxandroidble2.exceptions.BleDisconnectedException: Disconnected from MAC='E9:CF:8A:D0:01:19' with status 8 (GATT_INSUF_AUTHORIZATION or GATT_CONN_TIMEOUT)
        at io.reactivex.plugins.RxJavaPlugins.onError(RxJavaPlugins.java:367)
        at io.reactivex.internal.operators.observable.ObservableUnsubscribeOn$UnsubscribeObserver.onError(ObservableUnsubscribeOn.java:67)
        at io.reactivex.internal.operators.observable.ObservableSubscribeOn$SubscribeOnObserver.onError(ObservableSubscribeOn.java:63)

I'm not sure what else I should do - i've implemented a 'catch all' solution but don't like this approach;

RxJavaPlugins.setErrorHandler { e -> Timber.e(e, "Terminal Exception From RXJAVA was Not handled correctly") }

but don't see that as a good solution as expected that i should be-able to handle exception on the steam. Any suggestions of where I went wrong?

score 3 · Accepted Answer · answered May 03 '19 at 12:34

3

Your code is fine. The library has a flaw that does not allow to achieve your desired behaviour. More on the topic is on this library's wiki page.

While it is possible to design an API that would not throw UndeliverableException it would need to have a separate error Observable or Completable for BluetoothAdapter turning off and a separate one for RxBleConnection disconnect. The user would be responsible to mix those into their chain appropriately.

Current API does not allow it.

answered May 03 '19 at 12:34

Dariusz Seweryn

3,212
2
14
21

Thanks @Dariusz - I can happily live with the workaround as referenced on the wiki but my fear was that it was me doing something incorrectly - your answer resolves this concern. – Mannie May 03 '19 at 13:38

UndeliverableException thrown within a RxAndroidBle stream

1 Answers1