当客户端断开连接时，Node.js websocket崩溃

Question

我是NodeJS和Websockets的新手，但我正在尝试玩它。

我所做的是从串行端口读取传入数据，然后使用websocket将这些数据发送到网页。从这里开始一切正常。

• 我使用节点静态来服务我的网页
• websocket

问题是当客户端关闭浏览器时，我的NodeJS websocket服务器崩溃并出现以下错误:

root@WS-SERVER-2:~/app# node socketserver.js
open serial communication
Client disconnected.
/root/node-v0.10.29/lib/node_modules/ws/lib/WebSocket.js:187
    else throw new Error('not opened');
               ^
Error: not opened
    at WebSocket.send (/root/node-v0.10.29/lib/node_modules/ws/lib/WebSocket.js:187:16)
    at sendAll (/root/app/socketserver.js:30:16)
    at SerialPort.<anonymous> (/root/app/socketserver.js:58:8)
    at SerialPort.emit (events.js:95:17)
    at Object.module.exports.raw [as parser] (/root/node-v0.10.29/bin/node_modules/serialport/parsers.js:8:13)
    at Object.SerialPort.options.dataCallback (/root/node-v0.10.29/bin/node_modules/serialport/serialport.js:143:15)
    at SerialPortFactory.SerialPort._emitData (/root/node-v0.10.29/bin/node_modules/serialport/serialport.js:312:20)
    at afterRead (/root/node-v0.10.29/bin/node_modules/serialport/serialport.js:290:18)
    at /root/node-v0.10.29/bin/node_modules/serialport/serialport.js:304:9
    at Object.wrapper [as oncomplete] (fs.js:459:17)

以下是我的websocket/serialport代码:

var WebSocketServer = require('../node-v0.10.29/lib/node_modules/ws').Server;
var SerialPort = require('../node-v0.10.29/bin/node_modules/serialport').SerialPort;
var serialPort;
var portName = '/dev/ttyACM0';
var sendData = "";
var wss = new WebSocketServer({port: 8080});
var CLIENTS=[];
wss.on('connection', function(ws) {
       CLIENTS.push(ws);
    ws.on('message', function(message) {
        console.log('received: %s', message);
        sendAll(message);
    });
    ws.on('close', function() {
        console.log('Client disconnected.');
    });
    ws.on('error', function() {
        console.log('ERROR');
    });
    ws.send("");
});
function sendAll(message)
{
for(var i=0;i<CLIENTS.length;i++)
    {
    CLIENTS[i].send(message);
    }
}
serialListener();
function serialListener(debug)
{
    var receivedData = "";
    serialPort = new SerialPort(portName, {
        baudrate: 9600,
         dataBits: 8,
         parity: 'none',
         stopBits: 1,
         flowControl: false
    });
    serialPort.on("open", function () {
      console.log('open serial communication');
            // Listens to incoming data
        serialPort.on('data', function(data) {
             receivedData += data.toString();
          if (receivedData .indexOf('E') >= 0 && receivedData .indexOf('B') >= 0) {
           sendData = receivedData .substring(receivedData .indexOf('B') + 1, receivedData .indexOf('E'));
           receivedData = '';
         }
         // send the incoming data to browser with websockets.
       sendAll(sendData);
      });
    });
}

谁能帮我弄清楚这里出了什么问题?

Answer 1

我认为，您应该在close和error事件上从CLIENTS数组中删除套接字。否则，它将尝试向关闭的套接字发送消息

Answer 2

我也有同样的问题。原来我试图将事件发送到处于"关闭"状态的套接字。在广播消息之前检查每个套接字是专门打开的，为我修复了它:

    function sendAll(data){
        for(var i = 0; i < clients.length; i++){
            if(this.clients[i].readyState != this.clients[0].OPEN){
                console.error('Client state is ' + this.clients[i].readyState);
            }
            else{
                this.clients[i].send(data);
            }
        }
    }

Answer 3

在向客户端发送数据时尝试这样做:- socket是我当前的web socket对象。它覆盖了默认的>WebSocket.js类条件，抛出"未打开错误"。

if (socket.readyState != socket.OPEN) {
    console.error('Client state is ' + socket.readyState);
    //or any message you want
} else {
    socket.send(JSON.stringify(object)); //send data to client
}