<dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-websocket</artifactId>
      <exclusions>
        <exclusion>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-tomcat</artifactId>
        </exclusion>
      </exclusions>
    </dependency>

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    @Override
    public void registerStompEndpoints(StompEndpointRegistry stompEndpointRegistry) {
        //Set the endpoint and connect the front end through / ContextPath / endpoint
        stompEndpointRegistry.addEndpoint("/any-socket").addInterceptors(new HandshakeInterceptor() {

            /**
             * Intercept before shaking hands, store user information to attributes, and use subsequent user channels
             * @param request
             * @param response
             * @param wsHandler
             * @param attributes
             * @return
             * @throws Exception
             */
            @Override
            public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object> attributes) throws Exception {
                boolean result = false;
                HttpSession session =getSession(request);
                if (session != null){
                    User user =(User)getSession(request).getAttribute("user");
                    if(user != null){
                        attributes.put("user",user);
                        result = true;
                    }
                }
                return result;
            }
            @Nullable
            private HttpSession getSession(ServerHttpRequest request) {
                if (request instanceof ServletServerHttpRequest) {
                    ServletServerHttpRequest serverRequest = (ServletServerHttpRequest) request;
                    return serverRequest.getServletRequest().getSession();
                }
                return null;
            }
            @Override
            public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Exception exception) {}
        }).setHandshakeHandler(new DefaultHandshakeHandler() {
            /**
             * Specify the handshake body generation rule, which will be used when subsequent user messages are received. The default user channel is / User Destination Prefix /{Principal. getName}/ channel.
             * @param request
             * @param wsHandler
             * @param attributes
             * @return
             */
            @Nullable
            @Override
            protected Principal determineUser(ServerHttpRequest request, WebSocketHandler wsHandler, Map<String, Object> attributes) {
                return new UserPrincipal((User) attributes.get("user"));
            }
        //Support SockJS
        }).withSockJS();
    }

    @Override
    public void configureMessageBroker(MessageBrokerRegistry messageBrokerRegistry) {

        messageBrokerRegistry.setApplicationDestinationPrefixes("/app");
// The prefix information of the client subscription address, that is, the prefix information of the client receiving the message sent by the server
 messageBrokerRegistry.enableSimpleBroker("/queue", "/topic");
        //Specify user channel prefix, which is modifiable by default user
        messageBrokerRegistry.setUserDestinationPrefix("/queue");
    }

    @Override
    public void configureWebSocketTransport(final WebSocketTransportRegistration registration) {
        registration.addDecoratorFactory(new WebSocketHandlerDecoratorFactory() {
            @Override
            public WebSocketHandler decorate(final WebSocketHandler handler) {
                return new WebSocketHandlerDecorator(handler) {
                    @Override
                    public void afterConnectionEstablished(final WebSocketSession session) throws Exception {
                        String username = session.getPrincipal().getName();
                        //On-line related operations
                        super.afterConnectionEstablished(session);
                    }

                    @Override
                    public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus)
                            throws Exception {
                        String username = session.getPrincipal().getName();
                      //Offline related operations
                        super.afterConnectionClosed(session, closeStatus);
                    }
                };
            }
        });
    }
}

    @MessageMapping("/sendMsg")
    public void sendMsg(Principal principal, String message) {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy year MM month dd day HH:mm:ss");
        Message msg = JsonUtils.toObject(message, Message.class);
        try {
            msg.setSendTime(sdf.format(new Date()));
        } catch (Exception e) {
        }
        if (!"TO_ALL".equals(msg.getReceiver())) {
            template.convertAndSendToUser(msg.getReceiver(), "/chat", JsonUtils.toJson(msg));
        } else {
            template.convertAndSend("/notice", JsonUtils.toJson(msg));
        }
    }

    function connect() {
        //Connect endpoints, and add project paths
        var socket = new SockJS(_baseUrl+'any-socket');
        stompClient = Stomp.over(socket);
        stompClient.connect({}, function (frame) {
            //Listen for / topic/notice messages on this channel
            stompClient.subscribe('/topic/notice', function (message) {
                showMessage(JSON.parse(message.body));
            });
            //Listen for the current logged-in user's message on this channel, corresponding to the server convertAndSendToUser
            stompClient.subscribe("/queue/"+_username+"/chat", function (message) {
                showMessage(JSON.parse(message.body));
            });
        });
    }

        $("#send").click(function () {
            debugger;
            var msg = {
                "username":_username
                ,"avatar":_avatar
                ,"content":$("#message").val()
                ,"receiver":target
            };;
            //Send a message to the corresponding path of MessageMapping
            stompClient.send("/app/sendMsg", {}, JSON.stringify(msg));
            $("#message").val("");
        });