Question

我正在使用Node.js + Express + Express-ws创建一个应用程序，但是当我尝试在连接后发送消息时遇到以下错误：

const fs        = require('fs');
const http      = require('http');
const https     = require('https');
const express   = require('express');
const app       = express();

/*
const key   = fs.readFileSync('./security/server-key.pem', 'utf8');
const cert  = fs.readFileSync('./security/server-crt.pem', 'utf8'); 
const ca    = fs.readFileSync('./security/ca-crt.pem', 'utf8');
const credentials = {key: key, cert: cert, ca: ca};
var httpsServer = https.createServer(credentials, app);
*/

var httpServer = http.createServer(app);

httpServer.listen(8443, function(){
    console.log('Listening on *:8443 \n');
});

httpServer.on('connection', function(ws) {
    ws.on('message', function(message) {
        console.log('received: ' + message);
        ws.send(message);
    });
    ws.send('Hi there, I am a WebSocket server');
});

//ROUTES
app.get('/charger/:id', function(req, res){
    res.send('<h1>Hello ' + req.params.id + '</h1>');
});

app.get('*', function(req, res){
    res.status(404).send('404 — Not Found');
});

评论部分是为了验证我可以在以后使用HTPPS而不用过多修改内容。

错误如下：

TypeError: ws.send is not a function
    at Server.<anonymous> (index.js:26:5)
    at Server.emit (events.js:194:15)
    at TCP.onconnection (net.js:1517:8)

Answer 1

据我所知，这是因为您实际上并没有在任何地方使用express-ws软件包。另外，httpServer对象是http.Server类的实例，并且不具有websocket的内置知识。即使您在回调ws中调用该参数，它实际上也不是websocket对象-它是http.ClientRequest类的实例，该类没有send方法，因此{{1 }}错误。因此，要解决此问题，我认为您需要按照the docs遵循以下原则进行操作：

ws.send is not a function

希望有帮助，祝你好运！

express-ws：“ ws.send不是函数”

1 个答案: