I have just started out learning Node js. I can't understand why in output.txt I am seeing "2020 Septemberundefined undefined" in output.txt when I call:
http://localhost/?month=September&year=2020
I am expecting to see just "2020 September" in output.txt.
var http = require('http');
var url = require('url');
var fs = require('fs');
//create a server object:
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
var q = url.parse(req.url, true).query;
var txt = q.year + " " + q.month;
fs.appendFile('output.txt', txt, function (err) {
// nothing
});
res.end(); //end the respons
}).listen(8080); //the server object listens on port 8080
The favorite icon. Add console.log(req.url). You will see that the browser makes two requests.
Browser is sending requests for http://localhost:8080/favicon.ico, behind the scenes.
So whenever you hit http://localhost:8080/?month=September&year=2020,
node write "2020 September" to output.txt file, meanwhile browser hit favicon.ico request then node write again "undefined undefined" in output.txt file.
if you want to skip favicon.ico request,
var http = require('http');
var url = require('url');
var fs = require('fs');
//create a server object:
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
if (req.url != '/favicon.ico') {
var q = url.parse(req.url, true).query;
var txt = q.year + " " + q.month;
fs.appendFile('output.txt', txt, function (err) {
// nothing
});
}
res.end(); //end the respons
}).listen(8080);
Related
Im self-educating Node.js. I have created two simple HTML files (summer.html and winter.html) and noded the JS on node.js. I went on localhost:5354/summer.html (and winter.html). Nothing is showing up and I got an error message
This site can’t be reached
The connection was reset.
Try:
Checking the connection
Checking the proxy and the firewall
Running Windows Network Diagnostics
ERR_CONNECTION_RESET
I have tested other lessons and was able to display results on localhost:5354/ but this one doesnt work. What did I do wrong?
JS
var http = require('http');
var url = require('url');
var fs = require('fs');
http.createServer(function (req, res) {
var q = url.parse(req.url, true);
var filename = "." + q.pathname;
fs.readFile(filename, function(err, data) {
if (err) {
res.writeHead(404, {'Content-Type': 'text/html'});
return res.end("404 Not Found");
}
res.writeHead(200, {'Content-Type': 'text/html'});
res.write(data);
return res.end();
});
}).listen(5343);
Hit this URL
localhost:5343/summer.html
Because, You listen in 5343 PORT. But you hit 5354 Port
UPDATE
Thanks to #robertklep and #vallo for pointing out that I was not parsing the multipart request properly.
Here's the updated server code with some re-worked sample code from Busboy:
'use strict';
// Require
var http = require('http');
var Busboy = require('busboy');
var fs = require('fs');
// Server
var server = http.createServer(function(request, response) {
if (request.method === 'POST') {
var busboy = new Busboy({ headers: request.headers });
busboy.on('file', function(fieldname, file, filename, encoding, mimetype) {
file.pipe(fs.createWriteStream(`../db/images/${filename}`));
});
busboy.on('finish', function() {
response.writeHead(200, { 'Connection': 'close' });
response.end("That's all folks!");
});
return request.pipe(busboy);
}
response.writeHead(404);
response.end();
});
server.listen(8000, '192.168.7.25', () => {});
I am trying to post a jpg to an endpoint but the resulting image cannot be opened :
The file “image_copy.jpg” could not be opened. It may be damaged or
use a file format that Preview doesn’t recognize.
Some background:
Everything (servers, storage) are being hosted locally
Have made a decision to only use native Node modules like http and fs due to storage constraints on a microcontroller board
Am using form-data as it eases the pain of multi-part forms and uploads as well as sets the correct request headers
Here is some sample code broken into two scripts:
Server
'use strict';
// Require
var http = require('http');
// Server
var server = http.createServer((request, response) => {
var body = [];
request.on('data', function(chunk) {
body.push(chunk);
});
request.on('end', function() {
saveImage(Buffer.concat(body),null);
response.statusCode = 200;
response.end('thanks')
});
});
server.listen(8000, '192.168.7.25', () => {});
// Process
function saveImage(data,callback) {
var fs = require('fs');
fs.writeFile('../db/images/image_copy.jpg', data, function(err) {});
}
Client
'use strict';
// Require
var FormData = require('form-data');
var fs = require('fs');
var http = require('http');
// Vars
var form = new FormData();
// Process
form.append('my_file', fs.createReadStream('/temp/1.jpg'));
var request = http.request({
hostname: '192.168.7.25',
port: 8000,
path: '/api/premises/v1/image',
method: 'POST',
headers: form.getHeaders()
});
form.pipe(request);
request.on('response', function(res) {
console.log(res.statusCode);
});
After executing, the jpg is uploaded and saved to the correct file location (and also has the same file size as the source jpg) but the new image can't be opened.
Even if I encode the incoming chunk as binary and set the encoding on fs.writeFile to binary, I get a similar result.
What am I doing wrong? Thank you!
The client is uploading in multipart/form-data format, which is a format that can contain, amongst others, file data.
However, this means that the server should parse this format to extract the file data. Right now, the server is just taking the request body verbatim and writing it to a file.
The multiparty module can help you, and one of its usage examples shows you how to hook it up with http.Server: https://github.com/pillarjs/multiparty#usage
var multiparty = require('multiparty');
var http = require('http');
var util = require('util');
http.createServer(function(req, res) {
// parse a file upload
var form = new multiparty.Form();
form.parse(req, function(err, fields, files) {
res.writeHead(200, {'content-type': 'text/plain'});
res.write('received upload:\n\n');
res.end(util.inspect({fields: fields, files: files}));
});
}).listen(8000);
Using that, you can extract the file data from (I think) files.my_file and write it to the file.
To show my students a simple HTTP request and response that they could capture using Wireshark, I whipped up a simple Node.js HTTP server:
var fs = require('fs');
var http = require('http');
var port = 80;
var file = process.argv[2]; //This file contains a 42 byte HTML page
http.createServer(function (req, res) {
res.writeHead(200, { 'content-type' : 'text/html' }); // Sends first packet
fs.createReadStream(file).pipe(res); // Sends second packet
}).listen(port);
Unfortunately, the two lines transmitting the HTTP header and the HTML are sent as two separate TCP packets (even though they are both quite small). It would be simpler for my students if the HTTP header and HTML were just one packet. How could I change my code to do this?
var http = require('http');
var fs = require('fs');
var file = process.argv[2];
http.createServer(function(request, response) {
response.writeHeader(200, {"Content-Type": "text/html;"});
fs.readFile(file, function (err, html) {
if (err) {
throw err;
}
response.write(html);
response.end();
});
}).listen(8000);
the reason it won't work is that Node.js runs everything asynchronously. When you are loading your html file, the server creation starts the same time. By the time you are about to write your html to your tcp socket, the file most likely won't be ready.
I see what you were trying to do before... I misread your code because of the indentation. Let me know if this snippet works.
try using something like-
var file = process.argv[2];
fs.readFile(file, function (err, html) {
if (err) {
throw err;
}
http.createServer(function(request, response) {
response.writeHeader(200, {"Content-Type": "text/html"});
response.write(html);
response.end();
}).listen(8000);
});
1) Running a NodeJS server on localmachine
2) One device with App making a POST req to Node server.
3) XAMPP page making a GET request to get what device (from point 2) sent to Node server.
hope that's clear.
this is what I have, but GET receives undefined.
POST logs key1=value1
var http = require('http');
http.createServer(function (req, res) {
console.log(req.method);
var txt;
if(req.method == "POST") {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello World\n');
var url = require("url"),
parsedUrl = url.parse(req.url, false), // true to get query as object
queryAsObject = parsedUrl.query;
txt = JSON.stringify(queryAsObject);
console.log(txt);
} else {
// for GET requests, serve up the contents in 'index.html'
res.writeHead(200, {'Content-Type': 'text/html'});
res.end('Hello Worldzz\n'); // I WANT TO PASS txt here.
console.log("jaa" + txt);
}
}).listen(1337, 'my.ip.here');
console.log('Server running at http://my.ip.here:1337/');
-- update. CHECKing
function checkServer() {
$.ajax({
type: "GET",
url: "http://my.ip.here:1337/",
async: false,
}).success(function( text ) {
console.log("res" + text);
$( "h2" ).text( text );
});
}
This is just a simple scope problem. Since you want all requests to share the same txt var, you'll need to define txt in a place where all requests can access it.
var http = require('http');
var txt;
http.createServer(function (req, res) {
console.log(req.method);
//var txt;
If I have two node.js servers running, how can I tell which server called the processRequest function?
var http = require('http');
var https = require('https');
function processRequest(req, res) {
res.writeHead(200);
res.end("hello world, I'm on port: " + ???.port + "\n");
}
var server1 = http.createServer(processRequest).listen(80);
var server2 = https.createServer(processRequest).listen(443);
Originally I wanted the port number, but couldn't find the object/variable to give it to me. Based on the below answer it makes more sense to determine encrypted vs non-encrypted since the point is to know which of the http servers the request came in on.
The req parameter is an instance of IncomingMessage from which you can access the socket.
From there you can access both the localPort and remotePort.
Something like:
console.log(req.socket.localPort);
console.log(req.socket.remotePort);
This way you get the port number:
var http = require('http');
var server = http.createServer().listen(8080);
server.on('request', function(req, res){
res.writeHead(200, {"Content-Type": "text/html; charset: UTF-8"});
res.write("Hello from Node! ");
res.write(" Server listening on port " + this.address().port);
res.end();
});
In case you are using http://localhost:<port_number>, then you can get the port number using req.headers.host property.
Example:
const http = require('http');
const server = http.createServer((req, res)=>{
console.log(req.headers.host); // localhost:8080
console.log(req.headers.host.split(':')[1]); // 8080
})
server.listen(8080);
Instead of checking port numbers, you can also check the server instance or the connection object:
var http = require('http'),
https = require('https');
function processRequest(req, res) {
var isSSL = (req.socket.encrypted ? true : false);
// alternate method:
// var isSSL = (this instanceof https.Server);
// or if you want to check against a specific server instance:
// var isServer1 = (this === server1);
res.writeHead(200);
res.end('hello world, i am' + (!isSSL ? ' not' : '') + ' encrypted!\n');
}
var server1 = http.createServer(processRequest).listen(80);
var server2 = https.createServer(processRequest).listen(443);