To make it work you need to create a simple database to save chat, although it uses sqllite but when user is offline it save message on database and then send it to particular user.

Java's built-in java.net package: It provides support for socket programming and other network-related tasks. Netty: A high-performance, non-blocking I/O library for building network applications.

This tutorial is an introduction to socket programming in Java ... User Datagram Protocol (UDP). TCP and UDP are used for different purposes and both have unique constraints: TCP is relatively ...

Typically, this involves asking the user for a username and password, then comparing them with credentials stored in a database or directory service. However, this simple method is not enough to ...

The Java Scanner class is a simple, versatile ... Scanner class multiple times within the same program. You do not need to instantiate it with the new keyword each time. To continually grab input from ...