android - 如果连接丢失，RxAndroidBle 中的重置通知

Question

我正在尝试使用 RxAndroidBle 设置通知，但是当与外围设备的连接丢失时，我需要重新创建我设置的通知。我正在创建这样的通知:

connectionObservable
                .flatMap(rxBleConnection -> rxBleConnection.setupNotification(characteristicUuid))
                .doOnNext(notificationObservable -> runOnUiThread(this::notificationHasBeenSetUp))
                .flatMap(notificationObservable -> notificationObservable)
                .retryWhen(errors -> errors.flatMap(error -> {
                    if (error instanceof BleDisconnectedException) {
                        Log.d("Retry", "Retrying");
                        return Observable.just(null);
                    }
                    return Observable.error(error);
                }))
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(this::onNotificationReceived, this::onNotificationSetupFailure);

此代码与位于 here 的 RxAndroidBle 示例相同(请参阅 onNotifyClick())除了我添加了一个 .retryWhen() block 以在连接丢失时重试连接。建立连接后通知设置成功，调用onNotificationReceived()。在我反复连接失败之前，这有时会重新连接几次，并且重复调用 setCharacteristicNotification()。

这是显示我遇到的问题的一部分日志:

12-12 11:36:23.420 10841-10841/com.polidea.rxandroidble.sample I/CharacteristicOperationExampleActivity: Hey, connection has been established!
12-12 11:36:23.441 10841-10860/com.polidea.rxandroidble.sample D/BluetoothGatt: onConnectionUpdated() - Device=F9:A1:74:C0:09:3A interval=36 latency=0 timeout=500 status=0
12-12 11:36:24.819 10841-10841/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:24.823 10841-10841/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(204891860)
12-12 11:36:24.825 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(204891860)
12-12 11:36:24.889 10841-10859/com.polidea.rxandroidble.sample D/RxBle#BluetoothGatt$1: onDescriptorWrite descriptor=00002902-0000-1000-8000-00805f9b34fb status=0
12-12 11:36:24.893 10841-10841/com.polidea.rxandroidble.sample D/Notifications: Notifications set up
12-12 11:36:24.893 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(204891860)
12-12 11:36:26.252 10841-10860/com.polidea.rxandroidble.sample D/RxBle#BluetoothGatt$1: onCharacteristicChanged characteristic=00002a19-0000-1000-8000-00805f9b34fb
12-12 11:36:26.814 10841-10851/com.polidea.rxandroidble.sample I/zygote64: Compiler allocated 6MB to compile void android.view.ViewRootImpl.performTraversals()
12-12 11:36:27.681 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: onConnectionUpdated() - Device=F9:A1:74:C0:09:3A interval=24 latency=1 timeout=75 status=0
12-12 11:36:28.271 10841-10860/com.polidea.rxandroidble.sample D/RxBle#BluetoothGatt$1: onCharacteristicChanged characteristic=00002a19-0000-1000-8000-00805f9b34fb
12-12 11:36:28.401 10841-10851/com.polidea.rxandroidble.sample I/zygote64: Do full code cache collection, code=103KB, data=93KB
12-12 11:36:28.402 10841-10851/com.polidea.rxandroidble.sample I/zygote64: After code cache collection, code=101KB, data=74KB
12-12 11:36:30.261 10841-10859/com.polidea.rxandroidble.sample D/RxBle#BluetoothGatt$1: onCharacteristicChanged characteristic=00002a19-0000-1000-8000-00805f9b34fb
12-12 11:36:32.271 10841-10860/com.polidea.rxandroidble.sample D/RxBle#BluetoothGatt$1: onCharacteristicChanged characteristic=00002a19-0000-1000-8000-00805f9b34fb
12-12 11:36:34.283 10841-10859/com.polidea.rxandroidble.sample D/RxBle#BluetoothGatt$1: onCharacteristicChanged characteristic=00002a19-0000-1000-8000-00805f9b34fb
12-12 11:36:34.657 10841-10851/com.polidea.rxandroidble.sample I/zygote64: Do partial code cache collection, code=125KB, data=99KB
12-12 11:36:34.657 10841-10851/com.polidea.rxandroidble.sample I/zygote64: After code cache collection, code=125KB, data=99KB
12-12 11:36:34.658 10841-10851/com.polidea.rxandroidble.sample I/zygote64: Increasing code cache capacity to 512KB
12-12 11:36:36.323 10841-10860/com.polidea.rxandroidble.sample D/RxBle#BluetoothGatt$1: onCharacteristicChanged characteristic=00002a19-0000-1000-8000-00805f9b34fb
12-12 11:36:38.273 10841-10859/com.polidea.rxandroidble.sample D/RxBle#BluetoothGatt$1: onCharacteristicChanged characteristic=00002a19-0000-1000-8000-00805f9b34fb
12-12 11:36:40.311 10841-10860/com.polidea.rxandroidble.sample D/RxBle#BluetoothGatt$1: onCharacteristicChanged characteristic=00002a19-0000-1000-8000-00805f9b34fb
12-12 11:36:41.846 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: onClientConnectionState() - status=19 clientIf=6 device=F9:A1:74:C0:09:3A
12-12 11:36:41.854 10841-10859/com.polidea.rxandroidble.sample D/RxBle#BluetoothGatt$1: onConnectionStateChange newState=0 status=19
12-12 11:36:41.873 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:41.879 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(54354895)
12-12 11:36:41.884 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(54354895)
12-12 11:36:41.885 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:41.895 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:41.900 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(254074559)
12-12 11:36:41.902 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(54354895)
12-12 11:36:41.904 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:41.904 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(254074559)
12-12 11:36:41.909 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(231910737)
12-12 11:36:41.914 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:41.916 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(254074559)
12-12 11:36:41.918 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(231910737)
12-12 11:36:41.923 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:41.926 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(48916564)
12-12 11:36:41.928 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:41.935 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(258401717)
12-12 11:36:41.935 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(231910737)
12-12 11:36:41.937 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:41.937 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(48916564)
12-12 11:36:41.941 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:41.947 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(48916564)
12-12 11:36:41.947 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(261960698)
12-12 11:36:41.948 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(258401717)
12-12 11:36:41.949 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:41.952 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(184043911)
12-12 11:36:41.955 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue$2:  REMOVED DescriptorWriteOperation(261960698)
12-12 11:36:41.957 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(258401717)
12-12 11:36:41.957 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:41.958 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(184043911)
12-12 11:36:41.961 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:41.964 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(233807588)
12-12 11:36:41.966 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:41.969 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(92084997)
12-12 11:36:41.970 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(184043911)
12-12 11:36:41.970 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue$2:  REMOVED DescriptorWriteOperation(233807588)
12-12 11:36:41.972 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:41.973 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(92084997)
12-12 11:36:41.975 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:41.978 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(4571907)
12-12 11:36:41.979 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:41.982 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(85913073)
12-12 11:36:41.983 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(92084997)
12-12 11:36:41.984 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue$2:  REMOVED DescriptorWriteOperation(4571907)
12-12 11:36:41.985 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(85913073)
12-12 11:36:41.986 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:41.989 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:41.991 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(44454620)
12-12 11:36:41.993 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:41.995 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(260032157)
12-12 11:36:41.996 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(85913073)
12-12 11:36:41.997 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue$2:  REMOVED DescriptorWriteOperation(44454620)
12-12 11:36:41.998 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:41.998 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(260032157)
12-12 11:36:42.001 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:42.003 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(205319160)
12-12 11:36:42.005 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:42.007 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(141963529)
12-12 11:36:42.007 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(260032157)
12-12 11:36:42.009 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:42.010 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(205319160)
12-12 11:36:42.012 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:42.014 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(207186388)
12-12 11:36:42.016 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:42.019 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(12579274)
12-12 11:36:42.020 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(205319160)
12-12 11:36:42.020 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue$2:  REMOVED DescriptorWriteOperation(207186388)
12-12 11:36:42.021 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:42.022 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(141963529)
12-12 11:36:42.024 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:42.027 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(227068595)
12-12 11:36:42.029 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:42.031 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(34646817)
12-12 11:36:42.032 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(141963529)
12-12 11:36:42.033 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue$2:  REMOVED DescriptorWriteOperation(227068595)
12-12 11:36:42.034 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:42.034 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(12579274)
12-12 11:36:42.037 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:42.040 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(200262604)
12-12 11:36:42.041 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:42.044 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(3707597)
12-12 11:36:42.044 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(12579274)
12-12 11:36:42.046 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue$2:  REMOVED DescriptorWriteOperation(200262604)
12-12 11:36:42.046 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(34646817)
12-12 11:36:42.047 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:42.050 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:42.053 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(115232257)
12-12 11:36:42.054 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:42.056 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(34646817)
12-12 11:36:42.056 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(187740798)
12-12 11:36:42.058 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(3707597)
12-12 11:36:42.058 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue$2:  REMOVED DescriptorWriteOperation(115232257)
12-12 11:36:42.060 10841-10859/com.polidea.rxandroidble.sample D/Retry: Retrying
12-12 11:36:42.064 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: true
12-12 11:36:42.067 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(8463785)
12-12 11:36:42.067 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue: FINISHED DescriptorWriteOperation(3707597)
12-12 11:36:42.069 10841-10859/com.polidea.rxandroidble.sample D/BluetoothGatt: setCharacteristicNotification() - uuid: 00002a19-0000-1000-8000-00805f9b34fb enable: false
12-12 11:36:42.070 10841-10887/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:  STARTED DescriptorWriteOperation(187740798)
12-12 11:36:42.072 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue:   QUEUED DescriptorWriteOperation(22091834)
12-12 11:36:42.077 10841-10859/com.polidea.rxandroidble.sample D/RxBle#ConnectionOperationQueue$2:  REMOVED DescriptorWriteOperation(8463785)

如日志中所示，连接已成功建立，并且我收到了一些特征更改通知；然而，在我失去连接并重试连接后，我再次设置了特征通知，然后立即断开连接。

我的目标是能够模拟与蓝牙设备的长时间连续连接。当连接处于 Activity 状态时，我需要能够获得特征通知。如果使用 retryWhen() 不是重新连接和设置通知的正确方法，那么更好的解决方案是什么？

Answer 1

显然 ConnectionSharingAdapter 存在问题，在 RxBleDevice.establishConnection() 发出异常后，它无法正确释放 RxBleConnection。

使用简单的 RxJava API 应该可以解决问题:

subscription = rxBleDevice.establishConnection()
            .flatMap(rxBleConnection -> rxBleConnection.setupNotification(characteristicUuid))
            .doOnNext(notificationObservable -> runOnUiThread(this::notificationHasBeenSetUp))
            .flatMap(notificationObservable -> notificationObservable)
            .retryWhen(errors -> errors.flatMap(error -> {
                if (error instanceof BleDisconnectedException) {
                    Log.d("Retry", "Retrying");
                    return Observable.just(null);
                }
                return Observable.error(error);
            }))
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(this::onNotificationReceived, this::onNotificationSetupFailure);

当不再需要连接时，只需取消订阅subscription。也可以通过在 .subscribe() 函数之前使用 .takeUntil(Observable) 取消订阅上游，效果大致相同。

编辑:如果需要在代码中的多个位置之间共享相同的连接，则需要共享相同的 Observable。虽然可以使用 ConnectionSharingAdapter 实现它，但它似乎是上面提到的一个错误。直接替换可能是 ReplayingShare运营商。

或者，可以重新安排流程，以便可以通过单个 .subscribe() 来实现。有一个很好的(虽然高级)谈论它Managing State with RxJava by Jake Wharton .