The following is my code:

const http = require('http');
var server1 = http.createServer(function(req, res) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.write('request successfully proxied!' + '\n' + JSON.stringify(req.headers, true, 2) + '\n' + req.url);
    res.end();
    throw new Error("Error!!!");
});
server1.on("error", err=>console.log(err));
server1.listen(5060);

Why the exception thrown from the callback is not handled by the server1.on("error", ...) and the process is stopped? If such an exception can't be handled by listening on the "error" event, how could I handle such exceptions so that the http server can still run well from the time on?

The following is my code:

const http = require('http');
var server1 = http.createServer(function(req, res) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.write('request successfully proxied!' + '\n' + JSON.stringify(req.headers, true, 2) + '\n' + req.url);
    res.end();
    throw new Error("Error!!!");
});
server1.on("error", err=>console.log(err));
server1.listen(5060);

Why the exception thrown from the callback is not handled by the server1.on("error", ...) and the process is stopped? If such an exception can't be handled by listening on the "error" event, how could I handle such exceptions so that the http server can still run well from the time on?

• javascript
• node.js
• http
• server

• 3 The error in server1.on refers to the error event being emitted by the server and not a thrown Error object as is in your case. To handle the thrown error, you'd need try-catch. – Soubhik Mondal Commented Feb 29, 2016 at 16:43

1 Answer 1

Use emit instead throw:

const http = require('http');
var server1 = http.createServer(function(req, res) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.write('request successfully proxied!' + '\n' + JSON.stringify(req.headers, true, 2) + '\n' + req.url);
    res.end();
    // throw new Error("Error!!!");
    this.emit('error', new Error("Error!!!"));
});
server1.on("error", err=>console.log(err));
server1.listen(5060);