Where can I learn how to write a server in Java?

Question

Node.js

Prompt sites, resources, videos where they simply and in detail explain how to create a server-client in Java.

Answer 1

What a vague question.
What is the server for? What protocol is tcp, http, http rest with json return?
netty.io
https://grizzly.java.net/
This is for you for tcp or websocket's
jax-rs 2.0 for any rest + json or spring.io spring framework

Answer 2

For example, here - www.javable.com/javaworld/04_03/01
There is also a tutorial and a bunch of manuals on the site, the resource has stalled a bit, but the articles are still relevant