Java 'Byte' Server for quick TCP requests

I've been searching for what appears to be the most obvious example project of any networking library; a simple byte-sending (no fancy pipelining), quick-connecting, decent bandwidth, TCP server that can handle simultaneous clients and maybe a client to go along with it. I know this sounds rather a lot of demands, but surely someone has written this code before. It's generic.

I'm trying to write a TCP server that serves multiple simultaneous clients as quickly as possible. The requests are relatively small.

I've found many examples for different networking libraries that try to show off their amazing features, without demonstrating how to write a simple server. I'm more concerned with my application logic than creating the bare bones of sending bytes from one server to another. Why can't I find a library that provides an abstraction that promotes such usage?

So far I've got TCP servers written in Java NIO with and without multithreading and Netty. None of which fulfil the above goals. I know it's probably because I've done *something* wrong, but without adequate documentation (Netty) how am I meant to know what?

I know this could sound like a plea, but I'm lost right now and I know there's no point in reinventing the wheel so I'm reaching out. Hopefully others in the same position as me will see this post and also benefit from any wisdom anyone is willing to impart :)

Thanks to anyone who replies.