官方文档-spring websocket/stomp
官方文档-spring session

共享Session

WebsocketSTOMPConfig:

@Configuration
@EnableWebSocketMessageBroker
@ConditionalOnWebApplication
public class WebsocketSTOMPConfig extends AbstractSessionWebSocketMessageBrokerConfigurer<ExpiringSession> {
    /**
    *  AbstractSessionWebSocketMessageBrokerConfigurer实现了在handshake时获取httpsession，并且每次websocket消息发生时也刷新了httpsession的时间。同时在websocket session中加入了SPRING.SESSION.ID字段。
    */

    @Override
    protected void configureStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/ws")
                // 在握手时就获得user，判断是否登录。
           .addInterceptors(new SessionAuthHandshakeInterceptor())
           .setHandshakeHandler(new DefaultHandshakeHandler(){
               @Override
               protected Principal determineUser(ServerHttpRequest request, WebSocketHandler wsHandler, Map<String, Object> attributes) {
                   return new MyPrincipal((User) attributes.get("user"));
               }
           })
           .setAllowedOrigins("http://127.0.0.1:8081");
    }

    @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {
        registration.setInterceptors(new ChannelInterceptorAdapter() {
            @Override
            public Message<?> preSend(Message<?> message, MessageChannel channel) {
                System.out.println("recv : "+message);
                StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
                User user = (User)accessor.getSessionAttributes().get("user");
                return super.preSend(message, channel);
            }

        });
    }

    @Override
    public void configureClientOutboundChannel(ChannelRegistration registration) {
        registration.setInterceptors(new ChannelInterceptorAdapter() {
            @Override
            public Message<?> preSend(Message<?> message, MessageChannel channel) {
                System.out.println("send: "+message);
                return super.preSend(message, channel);
            }
        });
    }



    @Override
    public void configureMessageBroker(MessageBrokerRegistry config) {
        // 这是配置到 @MessageMapping Controller
        config.setApplicationDestinationPrefixes("/app");
        // 直接到broker  message handler
        config.enableSimpleBroker("/topic", "/queue");

    }

    class MyPrincipal implements Principal{

        private User user;

        public MyPrincipal(User user) {
            this.user = user;
        }

        @Override
        public String getName() {
            return String.valueOf(user.getId());
        }

    }
}

SessionAuthHandshakeInterceptor： 这是自定义的握手拦截，获取已登录的User

public class SessionAuthHandshakeInterceptor implements HandshakeInterceptor {

    private Logger logger = LoggerFactory.getLogger(this.getClass());

    @Override
    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object> attributes) throws Exception {
        HttpSession session = getSession(request);
        if(session==null || session.getAttribute("user")==null){
            logger.error("websocket权限拒绝");
            return false;
        }
        attributes.put("user",session.getAttribute("user"));
        return true;
    }

    @Override
    public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Exception exception) {

    }

    // 参考 HttpSessionHandshakeInterceptor
    private HttpSession getSession(ServerHttpRequest request) {
        if (request instanceof ServletServerHttpRequest) {
            ServletServerHttpRequest serverRequest = (ServletServerHttpRequest) request;
            return serverRequest.getServletRequest().getSession(false);
        }
        return null;
    }
}

然后在configureClientInboundChannel中可以通过以下获得User：

StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
User user = (User)accessor.getSessionAttributes().get("user");

还有一种获得User的方式，可以在WebsocketSTOMPConfig中注入SessionRepository来获得springsession：

StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
sessionRepository.getSession((String) accessor.getSessionAttributes().get("SPRING.SESSION.ID"))

设置Principal

Spring提供了”/user”前缀专门用于精准推送单个用户。

client 订阅 “/user/queue/msg”，spring通过UserDestinationMessageHandler重新设置client的订阅地址，使与”/user/{username}/queue/msg”绑定。

前端代码：

var url = "ws://"+window.location.host+"/project/ws";
var client = Stomp.client(url);
client.connect({}, function (message) {
    const subscription = client.subscribe("/user/queue/msg", function () {});
    client.send("/app/test2", {}, "Hello, STOMP");
},function (err) {
    alert(err);
});

Controller:

@Controller
public class MsgController {

    private Logger logger = LoggerFactory.getLogger(this.getClass());
    @Autowired
    private SimpMessagingTemplate simpMessagingTemplate;

    @MessageMapping("/test2")
    public void test(String str, Principal principal){
     simpMessagingTemplate.convertAndSendToUser(principal.getName(),"/queue/msg","haha2");
    }
}

在WebsocketSTOMPConfig中的configureStompEndpoints配置：

registry.addEndpoint("/ws")
   .addInterceptors(new SessionAuthHandshakeInterceptor())
   .setHandshakeHandler(new DefaultHandshakeHandler(){
       @Override
       protected Principal determineUser(ServerHttpRequest request, WebSocketHandler wsHandler, Map<String, Object> attributes) {
          return new MyPrincipal((User) attributes.get("user"));
       }
   });