Websocket 向指定用户发消息的方法

if (!Cookies.get('socketId')) {
  // 这里为模拟生成唯一id 建议 require('uuid')
  var uuid = Math.random() * 1000;
  Cookies.set('socketId', uuid)
}

function connectWebsocket() {
  let url = `ws://${document.location.host}`;

  var ws = new WebSocket(url);

  ws.onopen = function () {
    console.log("连接成功!");
    ws.send(
      JSON.stringify({
        type: "setSocketId",
        data: Cookies.get('socketId')
      })
    );
  };
  ws.onclose = function () {
    // 关闭 websocket
    console.log("连接已关闭...正在重连...");
    connectWebsocket()
  };
  ws.onmessage = res => {
    console.log("收到socket消息:", res.data)
    var data = JSON.parse(res.data)
    document.querySelector('#content').innerHTML += data.data;
  };
}

connectWebsocket()

wss.on('connection', function connection(ws, req) {
    ws.req = req;
    ws.sendJson = function (json) {
      if (this.readyState == 1) {
        this.send(JSON.stringify(json))
      }
    }
    ws.on('message', function (message) {
      message = JSON.parse(message);
      switch (message.type) {
        case 'setSocketId':
          ws.socketId = message.data;
          console.log(ws.socketId)
          break;
      }
    });
});
app.post('/api/socket/msg', function (req, res) {
    var query = req.body;
    console.log(query)

    var socketId = req.cookies.socketId;

    res.wss.clients.forEach(ws => {
      if (ws.socketId == socketId && ws.readyState == 1) {
        ws.sendJson({
          type:'testMsg',
          data:query.msg
        });
      }
    })

    res.send({})
})