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How can i make a local server using nodeJs?

I'm trying to make a local server using nodeJs but its not working.
What is tried
var http = require('http');
http.createServer(function(req, res) {
res.write('Hello');
req.end();
}).listen(8080);

Be careful when using response.end!
What is the difference between response.end() and response.send()?
response.end() will always send an HTML string, while response.send() can send any object type. For your example, both will serve the purpose since you are sending an HTML string of 'hello', but keep these cautions in mind as you proceed to build your server!
var http = require('http');
//Example with response.end()
http.createServer(function(request, response) {
response.end('Hello');
}).listen(8080);
//Example with response.send()
http.createServer(function(request, response) {
response.send('Hello');
}).listen(8080);
//Example with res.send() object
http.createServer(function(request, response) {
response.send({ message: 'Hello', from: 'Happy Dev' });
}).listen(8080);

The res (which stand for response) in the callback is a Stream. After you write all you want (headers, body) to the stream, you must end it like so:
res.end();
What you have is req.end().
Using req instead of res was your error.
Also, since you only write one line in this contrived example, you could write the buffer and end the stream in one go:
const server = http.createServer(function (req, res) {
res.end('Hello');
});
server.listen(8080);
Docs for response.end

I want to start a simple http web server but this isn't working

var http = require("http");
var fs = require("fs");
http.createServer(function(request, response) {
console.log("User request received");
response.writeHead(200, {"Content-Type": "Text/plain"});
fs.createReadStream(process.argv[3]).pipe(response);
response.end();
}).listen(process.argv[2]);
console.log("Server is running...");
This program takes the port number and the file path as command line parameters.
When I run it in node, even though I pass the correct command line arguments, the file is not served when accessed from the browser
I don't know where the error is occurring

This might not be the best answer but it looks like the call to response.end() is closing the stream before the file is served. Following the logic on this answer:
createReadStream().pipe() Callback
You need a callback on when the stream closes, so I found this works but again, I don't know if this is the most elegant solution:
var http = require("http");
var fs = require("fs");
http.createServer(function(request, response) {
console.log("User request received");
response.writeHead(200, {"Content-Type": "Text/plain"});
var t = fs.createReadStream(process.argv[3]).pipe(response);
t.on('close', function(){
response.end();
});
}).listen(process.argv[2]);

Combining Java and Node.js through Sockets

I have the following Node.js code:
var http = require('http');
http.createServer(function(req, res)) {
console.log("URL request"+req.url);
res.writeHead(200, {'Content-Type':'text/plain'});
res.end('Hello World\n');
}).listen(9898, '127.0.0.1');
console.log('Server locally running at http://127.0.0.1:9898/');
I am using the Socket class in Java to make a socket that also connects to port 9898. I want whatever the Node.js writes (in this case 'Hello World'), to be processed by a Java class. So far, this is what I have for the Java class:
Socket s = new Socket(serverAddress, 9898);
BufferedReader input =
new BufferedReader(new InputStreamReader(s.getInputStream()));
My question is how do I get the 'Hello World' to be read by the Java code, so that whenever I call System.out.println(input.readLine()), it prints 'Hello World'?

you had an extra ')' on the third line, but your code seems to otherwise work:
var http = require('http');
http.createServer(function(req, res) {
console.log("URL request"+req.url);
res.writeHead(200, {'Content-Type':'text/plain'});
res.end('Hello World\n');
}).listen(9898, '127.0.0.1');
console.log('Server locally running at http://127.0.0.1:9898/');
i guess you need to create some java functionality to make a http request to the url:port the node server is running on. it probably wont be as simple as 'input.readLine()'.
maybe something like this will help for getting the java code to get the data from node:
How can I get an http response body as a string in Java?

Node.js Simple Server JavaScript

I just started last week learning JavaScript and Node.js. Before that I developed with Java WebObjects and VB.NET. I just want to learn it for my self.
My brain is hurting after this week because of closures and other JavaScript stuff.
And now the question. To create a simple Node server I always found some code like this.
var http = require("http");
http.createServer(function(request,response) {
response.writeHead(200, {"Content-Type": "text/plain"});
response.write("Hello World");
response.end();
}).listen(3000);
Is there any difference if I would write the code like this?
var http = require("http");
var serverCallback = function(request, response) {
response.writeHead(200, {'Content-Type': 'text/plain'});
response.write("Hello World");
response.end();
}
var server = http.createServer(serverCallback);
server.listen(3000);
For me this is more readable. But I'm not really sure that its exact the same.

There is no difference in functionality. Use whatever style you like.

The only difference in this case how the variables are assigned, found this yesterday in HN
https://news.ycombinator.com/item?id=7672131

node.js send data to client?

I wonder how can I send data from node.js to client?
example node.js code -
var http = require('http');
var data = "data to send to client";
var server = http.createServer(function (request, response) {
response.writeHead(200, {"Content-Type": "text/plain"});
response.end("Hello World\n");
}).listen(8125);
Now, I want to send the data variable to client and log it with JavaScript..
How can I do that?
Thanks ;)
EDIT: Does anyone know how to send array?

If You Want to do it after response.end you should use Socket.io or Server Send Events.
If you want it before res.end, you would make your code look like:
var http = require('http');
var data = "data to send to client";
var server = http.createServer(function (request, response) {
response.writeHead(200, {"Content-Type": "text/plain"});
response.write(data); // You Can Call Response.write Infinite Times BEFORE response.end
response.end("Hello World\n");
}).listen(8125);