What does a Java developer need to know?

Question

Java

The point is this. I am programming in Java. I know and use encapsulation, inheritance and polymorphism, I work with collections, I can work with the OpenGL graphic library, as well as create an application using JFrame. I'm currently learning the Android SDK. In general, the question is this.
What else do I need to learn for my future professional programming? What books can you recommend on Java?
PS And a small question: will my small projects in the java language help me to enter the university?

Answer 1

Universities do not care about your achievements, and the fact that you have already mastered a decent piece of technology before entering. The university is a state institution, it does not care about efficiency. Therefore, I doubt that my projects will somehow help, but the fact that you do them is a very big plus when you look for a job as a junior. It's better to upload them to GitHub right now, and it's okay that the curves are oblique :)
What to learn in Java?
The patterns recommended above are great advice. Try to understand the main ones, write your own factory, singleton and others. Push them into your project (don't care what overengineering is - you're learning).
At one time I was very grateful to the resource: java-course.ru , pay attention to the part: java-course.ru/student/book1 it tells how to build your Spring application.

Answer 2

Design patterns.
They won't help.

Answer 3

In principle, in java, you can learn everything that you google, it will be both useful and practical.
Of course, it depends on the applications you develop, what is their conceptual nature and work, orientation and direction. If logic is involved, then you need to study algorithms and mathematics. If you are designing design-oriented applications, then the main thing is to study and train in design theory.
When entering a university, nothing will help you, except for experience in the development and creation of mathematical models and algorithms, since they are based on mathematical theory.
Struggling with mathematics, physics, computer science, and only then will there be success. And you will have time to level up in Java coding later as a student and after that, if you are not expelled yet. Study basic sciences if you really aspire for education and want to become a good javacoder

Answer 4

you need to know everything, or at least know in what form it can function and quickly and efficiently find information.
If you are interested in "minimal" knowledge, which conditionally draws a line, then see the topics and questions for certification of Oracle engineers in Java. For example, SE. If you can prove it, then pass the certification and get a certificate.

Answer 5

The most correct decision is to go to an interview and they will tell you what you don’t know :)
But judging by everything that the author is just going to act, there is no time for social security...

Answer 6

on hh.ru you can see technologies popular with employers =)