项目中需要向页面推送消息..决定采用websocket

部分代码copy网上的

config: websocket的配置

@Configuration
@EnableWebSocket
open class WebSocketConfig : WebSocketConfigurer {
    override fun registerWebSocketHandlers(p0: WebSocketHandlerRegistry?) {
        p0?.addHandler(MyWebSocketHander(),"/test")?.addInterceptors(MyHandshakeInterceptor())
    }
    @Bean open fun serverEndpointExporter() : ServerEndpointExporter {
        return ServerEndpointExporter()
    }
}

socketHandler类

  @ServerEndpoint("/test")
  @Component
  class MyWebSocket {
      companion object {
          val webSocketSet = CopyOnWriteArraySet<MyWebSocket>()
          var onlineCount = 0
      }
    var session: Session? = null
    @OnOpen
    fun onOpen(session: Session) {
        this.session = session
        webSocketSet.add(this)
        addOnlineCount()
        println("有新客户加入!当前在线人数 $onlineCount")
        sendMsg("你好!客户端")
        try {
            sendMsg("test")
        } catch(e: Exception) {
            println("${e.message}")
        }
    }
    @OnClose
    fun onClose() {
        webSocketSet.remove(this)
        subOnlineCount()
        println("客户退出!当前在线人数 $onlineCount")
    }
    @OnMessage
    fun onMsg(msg: String, session: Session) {
        println("客户端传来的消息:$msg")
        for (item in webSocketSet) {
            item.sendMsg("msg:$msg")
        }
    }
    fun subOnlineCount() {
        onlineCount--
    }
    fun addOnlineCount(): Int {
        return onlineCount++
    }
    fun sendMsg(msg: String) {
        this.session?.basicRemote?.sendText(msg)
    }
}

最后就是控制类

@PostMapping("xxxx")
@MessageMapping("/test")
    fun test(){
      val webSocketSet = MyWebSocket.webSocketSet
            for (item in webSocketSet) {
                   item.sendMsg("有订单导入!!")
                }
      }

到这里就可以实现服务器向web推送消息的方式了.