Data structures and java junior?

Question

Java

Does a java junior need to know in-depth data structures and be able to implement them?

Answer 1

Yes. Junior is the one who knows everything, can do everything, but he has no experience.

Answer 2

Java development is not decently expensive, so at least the second-year program of a third-rate university should be known.
I will omit the question for what it is necessary to know, I would rather ask how you are going to work without it?