›

MetaMotionR reading battery level causes NPE

SamSam
in Android

Hello. I read device battery level every 0.5 seconds asynchronously using ScheduledExecutorService. It works fine most of the time but rarely causes a NullPointerException thrown from mbientlab api library. Here's my code:

Created subscriber

    private Subscriber chargeHandler = (Subscriber) (data, env) -> {
        Settings.BatteryState batteryState = data.value(Settings.BatteryState.class);
        charge = batteryState.charge;
    };

When connecting

                    Settings boardSettings = metaWearBoard.getModule(Settings.class);
                    if (boardSettings == null) {
                        return null;
                    }
                    boardSettings.editBleConnParams()
                            .maxConnectionInterval(11.25f)
                            .commit();
                    settingsCapture.set(boardSettings);
                    return boardSettings.battery()
                            .addRouteAsync(source -> source.stream(chargeHandler));

Then every 0.5 seconds I do

settingsCapture.get().battery().read();

Stack trace:

java.lang.NullPointerException: Attempt to read from field 'java.lang.String com.mbientlab.metawear.android.BtleService$GattOp.msg' on a null object reference
    at com.mbientlab.metawear.android.BtleService.executeGattOperation(BtleService.java:108)
    at com.mbientlab.metawear.android.BtleService.addGattOperation(BtleService.java:101)
    at com.mbientlab.metawear.android.BtleService.access$600(BtleService.java:76)
    at com.mbientlab.metawear.android.BtleService$AndroidPlatform.writeCharacteristicAsync(BtleService.java:357)
    at com.mbientlab.metawear.impl.JseMetaWearBoard$1.sendCommand(JseMetaWearBoard.java:185)
    at com.mbientlab.metawear.impl.DataTypeBase.read(DataTypeBase.java:154)
    at com.mbientlab.metawear.impl.SettingsImpl$3.read(SettingsImpl.java:397)
    at com.solut.metaweardongles.device.DeviceState.readBatteryLevel(DeviceState.java:242)
    at com.solut.metaweardongles.device.DeviceManager$$Lambda$6.accept(Unknown Source)
    at java.util.HashMap$Values.forEach(HashMap.java:1268)
    at com.solut.metaweardongles.device.DeviceManager.updateDevicesState(DeviceManager.java:288)
    at com.solut.metaweardongles.device.DeviceManager.bridge$lambda$0$DeviceManager(DeviceManager.java)
    at com.solut.metaweardongles.device.DeviceManager$$Lambda$5.run(Unknown Source)
    at com.solut.metaweardongles.utils.ExecutorHelper$ExceptionLoggingRunnable.run(ExecutorHelper.java:25)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:428)
    at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:278)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:273)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
    at java.lang.Thread.run(Thread.java:760)

Comments

This discussion has been closed.