A secure TCP echo server that echoes all input it receives on any connection, after prepending the input with a fixed
string. The only difference between this example and
EchoServer is that this adds TLS.
This example just aims to demonstrate how to write the simplest TCP server, it is however, not of much use in general
primarily because it reads unstructured data i.e. there are no boundaries that define what constitutes "a message".
In order to define such boundaries, one would typically add a
ChannelHandler that converts the read raw
ByteBuffer to a structured message.