InternalFederateException and NullPointerException

[babangidazachariah]

What could cause the following error and how to address it:

    - InternalFederateException: Error code: 0x01000013: There was an error during an advance time.
    - Root Cause: NullPointerException: The application has not been initialized by the ambassador: the OperatingSystem is null.

[schwepmo]

This probably is an issue with your application but without any context it is hard to pinpoint the issue. When writing an application for a vehicle make sure that your application extends the AbstractApplication<T> class using a VehicleOperatingSystem.

For additional reference see here: https://eclipse.dev/mosaic/docs/develop_applications/

[babangidazachariah]

Thank you sir. I was able to figure it out. I was trying to instantiate objects of my classes in the onStartup() method, the error was or appeared to have been fixed after I moved the instantiations into another function and creating a schedule event to execute the function after the simulation has started. This I don't know why though.

Thank you

[schwepmo]

Alright, I'm glad you found a solution for your problem. If your classes require road positions, this could cause the issue. These are only available after onVehicleUpdated has been called. A common pattern we find in our applications is to call some initialize methods within the onVehicleUpdated-method with the condition if (previousVehicleData == null) { ... } as this will only happen once in the beginning of the simulation

[babangidazachariah]

I see. Thank you @schwepmo I really appreciate