[网络协议]SpringBoot整合WebSocket具体实现

引入pom

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

代码

@Component
@Service
@Slf4j
@ServerEndpoint("/websocket/{userId}")
public class WebSocketServer {


    //静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
    private static int onlineCount = 0;
    //concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。
    private static CopyOnWriteArraySet<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<WebSocketServer>();

    //与某个客户端的连接会话，需要通过它来给客户端发送数据
    private Session session;

    //接收sid
    private Long userId = null;

    private static MessageService  messageService;
    //webSocket中无法使用Autowired直接注入，需要通过方法注入的方式注入。
    @Autowired
    public void setChatService(MessageService  messageService) {
        WebSocketServer.messageService= messageService;
    }

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("userId") Long userId) {
        this.session = session;
        webSocketSet.add(this);     //加入set中
        this.userId = userId;
        addOnlineCount();           //在线数加1
        try {
            //通过userId查询是否该用户有待办的消息。然后调用发送消息方法发送给前端。
            //sendMessage("conn_success");
            List<MessageEntity> list = messageService.getUnreadByUserId(userId);

            String message = "";
            if(list!=null&&list.size()>0){
                message = JSONObject.toJSONString(list);
            }
            sendInfo(message,userId);
            log.info("有新窗口开始监听:" + userId + ",当前在线人数为:" + getOnlineCount());
        } catch (IOException e) {
            log.error("websocket IO Exception");
        }
    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose() {
        webSocketSet.remove(this);  //从set中删除
        subOnlineCount();           //在线数减1
        //断开连接情况下，更新主板占用情况为释放
        log.info("释放的sid为："+userId);
        //这里写你 释放的时候，要处理的业务
        log.info("有一连接关闭！当前在线人数为" + getOnlineCount());

    }

    /**
     * 收到客户端消息后调用的方法
     * @ Param message 客户端发送过来的消息
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("收到来自窗口" + userId + "的信息:" + message);
        //群发消息
        for (WebSocketServer item : webSocketSet) {
            try {
                item.sendMessage(message);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * @ Param session
     * @ Param error
     */
    @OnError
    public void onError(Session session, Throwable error) {
        log.error("发生错误");
        error.printStackTrace();
    }

    /**
     * 实现服务器主动推送
     */
    public void sendMessage(String message) throws IOException {
        this.session.getBasicRemote().sendText(message);
    }

    /**
     * 群发自定义消息
     */
    public static void sendInfo(String message, @PathParam("userId") Long userId) throws IOException {
        log.info("推送消息到窗口" + userId + "，推送内容:" + message);

        for (WebSocketServer item : webSocketSet) {
            System.out.println(item.userId);
            System.out.println(webSocketSet.size());
            try {
                //这里可以设定只推送给这个sid的，为null则全部推送
                if (userId == null) {

                } else if (item.userId.equals(userId)) {
                    item.sendMessage(message);
                }
            } catch (IOException e) {
                continue;
            }
        }
    }

    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    public static synchronized void addOnlineCount() {
        WebSocketServer.onlineCount++;
    }

    public static synchronized void subOnlineCount() {
        WebSocketServer.onlineCount--;
    }

    public static CopyOnWriteArraySet<WebSocketServer> getWebSocketSet() {
        return webSocketSet;
    }



}

测试

@Controller("web_Scoket_system")
@RequestMapping("/api/socket")
public class TestWebSocketController {
    //页面请求
    @GetMapping("/index/{userId}")
    public ModelAndView socket(@PathVariable String userId) {
        ModelAndView mav = new ModelAndView("/socket1");
        mav.addObject("userId", userId);
        return mav;
    }

    //推送数据接口
    @ResponseBody
    @RequestMapping("/socket/push/{userId}")
    public Map pushToWeb(@PathVariable Long userId, String message) {
        Map<String,Object> result = new HashMap<>();
        try {
            WebSocketServer.sendInfo(message, userId);
            result.put("code", userId);
            result.put("msg", message);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return result;
    }
}