The books which you have mentioned are a very good background when it comes to Java language. The problem with being a “backend developer” is that usually even if you don’t work on frontend you are still expected to know basics of frontend stuff.
When I’m interviewing a backend developer or rather web developer with focus on backend, I expect him to know:
- Framework which we use which is Spring 3-4
- Database: SQL and JPQL
- Knowledge of HTML
- Some familiarity with CSS
- Knowledge how web works: Get and post requests, rest services, json, sessions
When it comes to frameworks most popular one are Spring and Java EE6, of course there are much more but if company is using something less commonly known they less expect you to know it.
Basically if you can write from scratch a simple to-do list application all by yourself, you are ok to be junior level web dev.