I'm as new to Node and when I trying to run my first ever simple node app that makes an http connection to www.google.com host. While I tried some of the solutions suggested on prior threads nothing really seemed to help. While the below error is not a rare case but need someone to advise me what's missing from my setup/env.
source code - test.js - as simple as below -
var http = require('http');
var options = { host: 'www.google.com'};
http.get(options, function(err, res) {
console.log("GOT ERR?", err);
console.log("GOT RES?", res);});
I get the below error.
events.js:72
throw er; // Unhandled 'error' event
^
Error: getaddrinfo ENOTFOUND
at errnoException (dns.js:37:11)
at Object.onanswer [as oncomplete] (dns.js:124:16)
Your callback is wrong. Try to write your code as follow:
var http = require('http');
var options = { host: 'www.google.com'};
// notice that the callback only receives a res parameter
// errors are handled on an event below
var req = http.get(options, function(res) {
console.log("Got response: " + res.statusCode);
});
// handle errors
req.on('error', function(e) {
console.log("Got error: " + e.message);
});
Here is the documentation for http.get: http://nodejs.org/api/http.html#http_http_get_options_callback
The error that you are seeing (throw er; // Unhandled 'error' event) is because you do not have an even handler for the error event. Notice the req.on('error') in my code to address this.
Related
i have this code in express.
var express = require('express');
var http = require("http");
var https = require("https");
var app = express();
var optionsSB = {
host: 'domain.com',
path: '/wp-content/themes/domain/includes/ajax/get_properties.php'
};
var optionsLV = {
host: 'apiproperties.local',
path: '/properties/storeSB',
method: 'POST',
headers: {
'Content-Type': 'application/json',
}
};
https.get(optionsSB, function (https_res) {
var dataSB = "";
https_res.on("data", function (chunkSB) {
dataSB += chunkSB;
});
https_res.on("end", function () {
http.request(optionsLV, function(http_res){
var dataVL = "";
http_res.on("data", function (chunkVL) {
dataVL += chunkVL;
});
http_res.on("end", function () {
console.log(dataVL);
});
});
});
});
app.listen(3000, function () {});
I get this error
events.js:183
throw er; // Unhandled 'error' event
^
Error: connect ECONNREFUSED 127.0.0.1:80
at Object._errnoException (util.js:1022:11)
at _exceptionWithHostPort (util.js:1044:20)
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1182:14)
I already try some things but i dont know what is the problem, regards.
I follow some instruction from a tutorials and all works fine but that error i dont understand.
It will throw like this when you are getting an error in setting up the request with your https.get(), but you don't have any error handler to capture the error. You can supply an error handler:
https.get(...).on('error', function(err) {
// error here
console.log(err);
});
It appears that the specific error is ECONNREFUSED. It could be that the destination is not accepting your https connection or it could be that it doesn't like the way you were passing the options. Since all you have is a host and path, you can also just use the URL:
https.get("https://somedomain.com//wp-content/themes/domain/includes/ajax/get_properties.php", ...);
Normally, everything works, but when there is no internet connection my app throws an error:
events.js:160
throw er; // Unhandled 'error' event
^
Error: getaddrinfo ENOTFOUND
/* my code - putting this to try...catch have no effect: */
var http = require('http');
// (...)
var req = http.request(options, response => {
/* ... */
});
req.write(data);
req.end();
So what can I do when internet connection shuts down and I would like to prevent my app from stopping?
To prevent your app from stopping when external server's internet connection is down, you can catch getaddrinfo ENOTFOUND error and return error message to your end client. Please check this SO on how to catch getaddrinfo ENOTFOUND error.
In your case, the code would be:
var http = require('http');
// (...)
var req = http.request(options, response => {
/* ... */
});
req.on('error', function (err) {
// Check error type and console.log corresponding message.
});
req.write(data);
req.end();
I'm trying to use named pipes in my application. The problem is when I try to connect to the named pipe before the server is running, I get the following error:
events.js:141
throw er; // Unhandled 'error' event
^
Error: connect ENOENT \\?\pipe\\testpipe
at Object.exports._errnoException (util.js:870:11)
at exports._exceptionWithHostPort (util.js:893:20)
at PipeConnectWrap.afterConnect [as oncomplete] (net.js:1062:14)
How can I check if the pipe exists before attempting to connect to it?
Note: Wrapping my connect code in a try-catch doesn't prevent the error.
Here is my code:
var net = require('net');
var addr = '\\\\?\\pipe\\testpipe';
var client = net.createConnection({ path: addr }, function() {
console.log("Connected");
client.on('data', function(data) {
console.log("Recieved: " + data);
});
client.on('error', function(){
console.log(arguments);
});
}.bind(this));
Using the domain module prevents a fatal error. The following code can be used to safely run the connect code.
Not what I was hoping for, but the closed solution since there have been no answers.
var net = require('net');
var domain = require('domain');
var addr = '\\\\?\\pipe\\testpipe';
var d = domain.create();
d.on('error', function(err) {
console.error(err);
});
d.run(function() {
var client = net.createConnection({ path: addr }, function() {
console.log("Connected");
client.on('data', function(data) {
console.log("Recieved: " + data);
});
client.on('error', function(){
console.log(arguments);
});
}.bind(this));
});
make the socket, then listen for an error event, then call connect and it won't be thrown: https://nodejs.org/api/net.html#net_event_error_1
All,
I have a simple Express web server on Windows Node. I can't work out how to capture the error if I'm trying to start the server on the same port as another instance of Express already running. The error middleware won't capture it and the usual .on("error", function ()....) doesn't work either, and the whole Node application bombs - I want to capture it gracefully.
Here is the code:
var express = require('express');
var compression = require('compression')
var app = express();
var __dirname = ""
app.use(compression({ threshold: 512 }));
var oneYear = 86400000 * 365;
app.enable('etag')
app.use(express.static(__dirname + '../../HAWebClient', { maxAge: oneYear }));
app.use(function (err, req, res, next) {
if (!err) return next();
console.log('<-------Error Occured ----->');
res.send(500, JSON.stringify(err, ['stack', 'message']));
});
app.on("error", function (err) {
status("SYSTEM/HTTP", "Error with the web server: " + err);
// Do stuff with error
});
app.listen(80);
and I get
events.js:72
throw er; // Unhandled 'error' event
^
Error: listen EADDRINUSE
at errnoException (net.js:904:11)
at Server._listen2 (net.js:1042:14)
at listen (net.js:1064:10)
at Server.listen (net.js:1138:5)
at Function.app.listen (C:\Users\deandob\Documents\GitHub\PluginMgr\PluginMgr\node_modules\express\lib\application.js:546:24)
at webSvr (C:\Users\deandob\Documents\GitHub\PluginMgr\PluginMgr\PlugMgr.js:298:9)
at Object.<anonymous> (C:\Users\deandob\Documents\GitHub\PluginMgr\PluginMgr\PlugMgr.js:271:1)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
Press any key to continue...
Don't want to capture this in Node's global error handler (which loses error context) - this error should be able to be captured by app.on("error,....) but I'm obviously missing something here. Thanks for the input!
When the port is already in use, app.listen(80); will throw an exception asynchronously (the exception you see in your error log) if you don't have an error handler on the server. The server, in this case, is the return value from app.listen(), not the app object which is why you attempt at handling the error was not working.
Rather than let that exception go to the system which will shut-down your app, you can catch the error and prevent the exception like this:
var server = app.listen(8080);
server.on('error', function(e) {
console.log(e);
// put your code here
});
And, then decide what to do in the error handler. I have tested this solution in a sample server and it does work.
FYI, the relevant documentation is on the socket object here: https://nodejs.org/api/net.html#net_server_listen_port_host_backlog_callback
I am trying to create a simple server and a simple client with node.js using http module. Server is working fine but client is not. Please help me to find the bug...
Server Is :
var server = require('http').createServer();
server.on('request', function(req, res){
res.end("hello, world");
});
server.listen(4000);
Client Is :
var options = {
host : 'localhost',
port : 4000,
method : 'GET',
path " '/'
};
require('http').request(options, function(res){
console.log(require('util').inspect(res));
res.on('data', function(data){
console.log(data);
});
I am running them in different terminal windows as node server.js & node client.js.
I am getting below mentioned error on the client.js running terminal after around 10 mins.
events.js:72
throw er; // Unhandled 'error' event
^
Error: socket hang up
at createHangUpError (http.js:1473:15)
at Socket.socketOnEnd [as onend] (http.js:1569:23)
at Socket.g (events.js:175:14)
at Socket.EventEmitter.emit (events.js:117:20)
at _stream_readable.js:920:16
at process._tickCallback (node.js:415:13)
Thanks !
The request() method of the HTTP library will not automatically end requests, therefore they stay open, and time out. Instead, you should either end the request using req.end(), or use the get() method, which will do so automatically.
var http = require('http');
var req = http.request(options, function(res) {
// handle the resposne
});
req.end();
Or:
http.get(options, function(res) {
// handle the resposne
});