我理解的spring boot WebSocket

第一步，maven
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>

第二步，Configuration

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {
    @Override
    public void registerStompEndpoints(StompEndpointRegistry stompEndpointRegistry) {
        //简单来说就是设置一个节点，路径名字
        //前端js初始化    new SockJS('/项目名称/xunWS');
        stompEndpointRegistry.addEndpoint("/xunWS").withSockJS();
    }

    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        //可以理解为前缀，参数可以填多个
       //@SendTo("/topic/orderN")
        registry.enableSimpleBroker("/topic","/queue");
    }
}

第三步，Controller
"/topic/orderN"其实就是一个标识，发送和接收时用到。"/topic"是Configuration中设置的registry.enableSimpleBroker("/topic");

@Controller
public class WSOrderController extends BaseController {

    @Autowired
    private SimpMessagingTemplate template;

    @MessageMapping("/orderN")
    @SendTo("/topic/orderN") 
    public ConfigModel orderNotify(ConfigModel msg){
        if (msg instanceof ConfigModel) {
            return msg;
        }else {
            ConfigModel m = new ConfigModel();
            m.setConf_value(msg.toString());
            m.setConf_key("c_msg");
            m.setConf_id(123456);
            return m;
        }
    }

    @Scheduled(cron = "0 0/1 * * * ?")//每分钟执行一次
    public void demo() {
//后台发送，第一参数是标识，第二参数是Object。和ios的通知中心类似
//前端js接收设置该标识就可以接收该消息，其中不会跑orderNotify方法
//后台直接调用orderNotify方法，前端是不会触发接收器的
//即使orderNotify方法去掉，也能行得通
        template.convertAndSend("/topic/orderN", new Date().toString());
    }
}////

第四步，js页面。jquery.min.js sockjs.min.js stomp.min.js

<script th:inline="javascript">
    /*<![CDATA[*/
    $(function(){
        connect();
        setInterval("send()",9000);
    });
    var stompClient;
    function connect() {
        var sockjs = new SockJS('/项目名称/xunWS');
        stompClient = Stomp.over(sockjs);
        stompClient.connect({},function (frame) {
            console.log('===========Connected:'+frame);
//设置接收标识[路径]
            stompClient.subscribe('/topic/orderN',function (response) {
//返回来的是json数据
                console.log("=========="+response.body);
            });
        });
    }
    function send() {
//js端发送信息，这个会跑后台orderNotify方法，"/orderN"和 @MessageMapping("/orderN")对应
//orderNotify方法设置了@SendTo("/topic/orderN") ，执行完orderNotify方法后会触发上面的subscribe。
        stompClient.send("/orderN", {}, JSON.stringify({'conf_id':'1000','conf_key':'c_duo','conf_value':'我爱duoduo'}));
    }
    /*]]>*/
</script>