This screencast shows how to create a simple Java application using test driven development (TDD). That is: write the tests FIRST, then implement the actual code. Refactor. Then do the same thing all over again.
The screencast also shows that Emacs is now, thanks to lsp-mode, dap-mode, yasnippets and many others, an excellent Java editor. My configuration can be found here: https://github.com/skybert/my-little-...
Happy coding!