OOP Concepts
Description of main Object Oriented Programming (OOP) concepts in Java - Encapsulation, Inheritance, and Polymorphism.
Full lesson
Overloading and Overriding
What are the method overloading and overriding, rules, and examples? Difference between these two concepts. The main usage of overriding.
Full lesson
Lambda in Java Language
Lambda expressions, method references, java.util.function interfaces: Predicate, Supplier, Consumer, Function, their primitive and binary specializations.
Full lesson
Inner Class
Features, syntax, and examples of a regular inner class, a method-local inner class, an anonymous inner class, and a static nested class.
Full lesson
Using try-catch and finally block in Java. Handle multiple exceptions in one block. The AutoCloseable resource in the try-with-resources statement in Java 7.
Full lesson

Why should I learn Java?

Java has a rich API, which allows to solve different problems, but still is easy in learning. It has a lot of forums, resources and still is growing.

Oct 20, 2012
Hi! Good site! Thanks.
Nov 22, 2012
good site,thanks for your knowledge sharing
Jan 15, 2013
I think this is a real great article post.Really thank you! Cool.
Feb 27, 2013
Hi! I cannot find search on the site. How can I find some information that I need use key e.g. "Optimistic locking"? Thanks
Feb 27, 2013
Hi JWood! There is no search on site now, but it will be implemented in the future.
Mar 20, 2013
hi, I see that this site is written in Java. Do you use a framework? Do you use JPA or JDBC? According to you, how many request this website can handle in 1 second?
Mar 22, 2013
Hi, Long! The site is written using Servlets, EJB and JPA. I didn't calculated how many request the website can handle.
Aug 10, 2013
Great resource! Thank you for your work.
Oct 17, 2013
Very useful for me
May 22, 2015
Hi! It would be nice to be able to print quistions with answers for reading offline :)
May 12, 2016
Nataly, hope to add such feature in the future!:)
Jul 8, 2016
thank your very much for your clarification ! it's very useful :)
Jul 8, 2016
BadriaAch, glad to be helpful!
Oct 8, 2020
it is not detecting checks in the tests
Jan 28, 2021
По окончанию курса выдается сертификат?
Jan 28, 2021
Сертификаты пока не выдаем.