Spring Boot WebSocket: Chat Example

Writing a simple messaging system using Spring Boot, WebSocket, STOMP, StompJS, SockJS libraries.
In this video https://www.youtube.com/watch?v=0qvT3EujjWw&t=17s
we created a simple chat using the above-mentioned technologies. This time we complicated our code a little bit:)
Link to github: https://github.com/caligula95/spring-websocket-chat