Strange behavior while using Container::addChild method reference on Lemur element collection: ClassNotFoundException instead of compiler error. Probable java bug?

User Code & Projects lemur
1

Hello all,

today I encountered a strange behavior when using lambdas on lemur elements (actually it seems to me that this is not a Lemur bug):
For generating a radio button array I collected a couple of check boxes inside a list. I am using something like this for generating checkboxes:

   List<Checkbox> checkboxList = Stream.of("1","2","3")
                  .map(strKey -> new Checkbox(strKey))
                  .collect(Collectors.toList());

this actually works fine. But whenever I call the following method:

checkboxList.forEach(container::addChild);

Compiler runs smoothly but during runtime I receive an strange error which I do not really understand:

java.lang.NoClassDefFoundError: spacecraft/gui/inflight/elements/ControlGuiAutopilotAcceleration
at spacecraft.gui.inflight.InflightGuiAutopilots.<init>(InflightGuiAutopilots.java:51)
at spacecraft.gui.inflight.InflightGui.<init>(InflightGui.java:81)
at spacecraft.Main.simpleInitApp(Main.java:85)

But: When I call the method using a plain lambda

    checkboxList.forEach(checkbox -> container.addChild(checkbox));

everything works fine.

I do not understand where this error comes from and why a NoClassDefFoundError is thrown. It seems to me that it has something to do with the Container::addChild vararg method. Whenever I use the method references on the verarg method compilation seems to be interrupted silently without an error.

I am using 3.1.0 stable FINAL on macOS Sierra 10.12.6 (MacBook Pro (Retina 13 Zoll))

Regards,
Harry

2

…what’s at that line?

3

this is one of my upper level window which calls interactive control containers dynamically. ControlGuiAutopilotAcceleration is the class wich I modified with the code shown above.
The constructor of the class ControlGuiAutopilotAcceleration is called here.

// The main constructor of ControlGui is called here passing the container for attachment
// and a spatial supplier for data read/write
private final ControlGuiAutopilotAcceleration accelerationAp
        = new ControlGuiAutopilotAcceleration(autopilotAccelerationContainer,
                () -> CharacterSelector.CurrentVessel.apply(this));

I already validated the code, it works.