The Java ecosystem is vast and there is very little you can say about it generally.
It's trivially easy to write Java programs without (ab)using inheritance. It's trivially easy to write Java programs in a functional style. There are countless libraries that will provide just about any programming interface you like, the only hard part is picking.
It's trivially easy to write Java programs without (ab)using inheritance. It's trivially easy to write Java programs in a functional style. There are countless libraries that will provide just about any programming interface you like, the only hard part is picking.