Links to courses, which could help begin your journey with JAVA.
Tim Buchalka, best video course I ever found https://www.udemy.com/share/1000wYAkcbdVlbQ3w=/ [ENG]
Samouczek Programisty http://www.samouczekprogramisty.pl/kurs-programowania-java/ [PL]
Good step by step Java course http://moocfi.github.io/courses/2013/programming-part-1/ [ENG]
JAVA BRAINS https://www.youtube.com/user/koushks
Good practises and designs in JAVA http://www.javapractices.com/home/HomeAction.do
JUG Optionals, Lambdas, Streams. Good examples,how to use properly https://youtu.be/bjaNWBKQroA
Przemysław Bykowski http://bykowski.pl
Yet another technical blog http://blog.mloza.pl/
JPA basics, Really helping when you make your first steps with JPA:
https://docs.oracle.com/javaee/5/tutorial/doc/bnbqa.html
https://docs.oracle.com/javaee/7/tutorial/partpersist.htm#BNBPY
next step should be actual Spring Data JPA reference
Jakub Kubryński JPA - beyond copy-paste https://www.youtube.com/watch?v=UPWkpl5PL_w
Jens Schauder Spring Data JPA https://youtu.be/Zyqpo8gxSO0 Jens Explained some misunderstanding during working with Spring Data JPA
https://12factor.net/pl/ Metodologia dwunastu aspektów, czyli jak wytwarzać nowoczesne, łatwe w utrzymaniu oprogramowanie typu SaaS software-as-a-service [PL]
REST - know the rules https://www.youtube.com/watch?v=lGLGW7EOzVY
https://github.com/akullpp/awesome-java
https://github.com/Vedenin/useful-java-links
https://github.com/java-lang/awesome-java
https://github.com/s4kibs4mi/java-developer-roadmap
and remember Java was created for writing best looking code!
https://alibaba.github.io/Alibaba-Java-Coding-Guidelines/ If You are at the beginning of your journey, I'm pretty sure that u should read this at least two times❗
https://google.github.io/styleguide/javaguide.html
https://github.com/twitter/commons/blob/master/src/java/com/twitter/common/styleguide.md
https://petroware.no/javastyle.html