Below are some of the good Java repositories to learn it better:-
iluwatar/java-design-patterns.
javaee-samples/javaee7-samples.
Moreover, these two repositories there are many other Java programmers who have difficulties with GitHub use. Here are two Java projects that make GitHub easy and profitable:
Gitblit (gitblit/gitblit) Gitblit is an open-source, pure Java Git solution for managing, viewing, and serving Git repositories. It can also serve repositories over the GIT, HTTP, and SSH transports. Gitblit can also authenticate against multiple providers and it allows you to get up-and-running with an attractive, capable Git server in less than 5 minutes. Also, it has 787 stars on GitHub.
To know more about these technologies whether if you are an absolute beginner or you have a little knowledge of GitHub in that case to learn GitHub and all its concepts such as pull request or creating a repository in detail which is necessary for a programmer you can learn it by taking up the GitHub training course. If you like to read then you can have a look at the GitHub tutorial. If you want to learn it by watching the video tutorial then you can have a look at the following tutorial:- .