HTTP Server

import http from 'node:http'
 
function handler(request, response) {
  response.writeHead(200, { 'Content-type':'text/plain' })
  response.write('hello world')
  response.end()
}
 
const server = http.createServer(handler)
server.listen(8080)

package main
 
import (
	"fmt"
	"net/http"
)
 
func main() {
	http.HandleFunc("GET /", func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte("hello world"))
	})
 
	http.HandleFunc("GET /hello/{name}", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintf(w, "hello %s", r.PathValue("name"))
	})
 
	if err := http.ListenAndServe(":8080", nil); err != nil {
		panic(err)
	}
}

// Cargo.toml: axum = "0.8"
// Cargo.toml: tokio = { version = "1", features = ["full"] }
use axum::extract::Path;
use axum::routing::get;
use axum::Router;
 
async fn hello(Path(name): Path<String>) -> String {
    format!("hello {name}")
}
 
#[tokio::main]
async fn main() {
    let app = Router::new()
        .route("/", get(|| async { "hello world" }))
        .route("/hello/{name}", get(hello));
 
    let listener = tokio::net::TcpListener::bind("0.0.0.0:8080").await.unwrap();
    axum::serve(listener, app).await.unwrap();
}

import Network
 
let listener = try NWListener(using: .tcp, on: 8080)
 
listener.newConnectionHandler = { connection in
    connection.start(queue: .main)
    connection.receive(minimumIncompleteLength: 1, maximumLength: 65536) { data, _, _, _ in
        guard let data, let request = String(data: data, encoding: .utf8) else { return }
        let path = request.split(separator: " ")[1] // "GET /hello/neko HTTP/1.1" -> "/hello/neko"
 
        let status: String
        let body: String
        if path == "/" {
            status = "200 OK"
            body = "hello world"
        } else if path.hasPrefix("/hello/") {
            status = "200 OK"
            body = "hello \(path.dropFirst("/hello/".count))"
        } else {
            status = "404 Not Found"
            body = "not found"
        }
 
        let response = "HTTP/1.1 \(status)\r\nContent-Length: \(body.utf8.count)\r\n\r\n\(body)"
        connection.send(content: response.data(using: .utf8), completion: .contentProcessed { _ in connection.cancel() })
    }
}
 
listener.start(queue: .main)
dispatchMain()

import com.sun.net.httpserver.HttpServer;
import java.net.InetSocketAddress;
 
void main() throws Exception {
    var server = HttpServer.create(new InetSocketAddress(8080), 0);
 
    server.createContext("/", exchange -> {
        byte[] body = "hello world".getBytes();
        exchange.sendResponseHeaders(200, body.length);
        exchange.getResponseBody().write(body);
        exchange.close();
    });
 
    server.createContext("/hello/", exchange -> { // prefix match, no {name} pattern like ServeMux
        String name = exchange.getRequestURI().getPath().substring("/hello/".length());
        byte[] body = ("hello " + name).getBytes();
        exchange.sendResponseHeaders(200, body.length);
        exchange.getResponseBody().write(body);
        exchange.close();
    });
 
    server.start();
}

const response = await fetch('http://localhost:8080')
console.log(await response.text())

package main
 
import (
	"fmt"
	"io"
	"net/http"
)
 
func main() {
	res, err := http.Get("http://localhost:8080")
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
 
	body, err := io.ReadAll(res.Body)
	if err != nil {
		panic(err)
	}
	fmt.Println(string(body))
}

// Cargo.toml: reqwest = "0.13"
// Cargo.toml: tokio = { version = "1", features = ["full"] }
#[tokio::main]
async fn main() {
    let body = reqwest::get("http://localhost:8080").await.unwrap().text().await.unwrap();
    println!("{body}");
}

import Foundation
 
let (data, _) = try await URLSession.shared.data(from: URL(string: "http://localhost:8080")!)
print(String(data: data, encoding: .utf8)!)

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
 
void main() throws Exception {
    var client = HttpClient.newHttpClient();
    var request = HttpRequest.newBuilder(URI.create("http://localhost:8080")).build();
 
    var response = client.send(request, HttpResponse.BodyHandlers.ofString());
    IO.println(response.body());
}