At the beginning, I thought robovm is a full Java VM, after I give it a try, realized it is not. Obviously robovm doesn't implement all the Java SE VM features, but what kind of features it doesn't implement, I can't find it documented somewhere.
I encounter many compatibility issue while I tried to integrate freemarker and itext into it. For example java.beans package missing and (a lot more actually) etc. The weird things is, it doesn't show the error during compile time but only during iOS runtime.
I can't find any document matrix to describe the implementation difference (java packages) between robovm and Java SE (either Oracle or OpenJDK), do we actually have such matrix documented somewhere?
RoboVM (MobiVM) bundles Android 4.4 runtime.
And Java RT Api is limited to one that was in 4.4.
There is work in progress to bring Android 10/11 libcore to RoboVM.
RoboVM shows warning about missing classes (as phantom class message) during compilation, not error. As class not found it is normal case in Java runtime world.