Ask HN: Good resources to learn Java EE
In my new workplace, we have several web projects built with Java EE. I had not done any Java programming before starting here. Two months in, I am able to contribute to maintenance of said projects and develop new features based on the existing code, but I lack knowledge to meaningfully improve the design of the application (meaning architecture &#x2F; code patterns). There is only one other person who knows more than I do about Java EE (he built the things), but he does not have too much knowledge about the more advanced aspects of Java EE application design either.
So could you recommend any good resources for learning Java EE? Especially about:
- load balancing &#x2F; HA, 
- multithreading, 
- developing an API for external consumption (not entirely Java EE related). 
We are not using the Spring framework. 
Any recommendation about good design patterns in Java EE is also very appreciated.