Well no, Java isn’t the best of languages but my criticism stems from other issues, such as weak type system, certain inscrutably bad decisions about the runtime libraries and other, but this code is bad also according to any self respecting java developer.

An untyped (that is, it cops out to int) bunch of public static’s that should’ve been an enum. Daft combination of builders and constructors. Magic numbers. Adapter methods that should go into their own class. Validators that should also go into their own class (and even there, implemented differently, not as a parameterless method). Transformers that could be modeled as their own class (all these “in their own class” are for testabilty.) some of the names in these adapters suggest some other domain concerns (UI) are leaking into this model class.

IOW, it’s a mess by any standard