this is a simple network service that reverses strings. I'm using it to test out Project Loom

ReversingServiceApplication.java

package com.example.demo;

import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * simple reversing service. Use with: {@code  curl https://www.wikipedia.org/ | nc 127.0.0.1 9090 }
 */
@SpringBootApplication
public class ReversingServiceApplication {

    @Bean
    ApplicationRunner runner() {
        var ex = Executors.newVirtualThreadPerTaskExecutor();
        var port = 9090;
        var server = new Server(ex, port);
        return args -> server.start();
    }

    public static void main(String[] args) {
        SpringApplication.run(ReversingServiceApplication.class, args);
    }

}

class Server {

    private final int port;

    private final ExecutorService executor;

    Server(ExecutorService executor, int port) {
        this.port = port;
        this.executor = executor;
    }

    private static void handleRequest(Socket socket, InputStream in, OutputStream out) throws Throwable {
        try {
            var next = -1;
            var baos = new ByteArrayOutputStream();
            while ((next = in.read()) != -1)
                baos.write(next);
            var reversedBytes = new StringBuilder(baos.toString())
                    .reverse()
                    .toString()
                    .getBytes(StandardCharsets.UTF_8);
            out.write(reversedBytes);
        } ///
        finally {
            socket.close();
        }
    }

    public void start() throws Exception {
        try (var serverSocket = new ServerSocket(this.port)) {
            while (true) {
                var client = serverSocket.accept();
                var is = client.getInputStream();
                var os = client.getOutputStream();
                this.executor.submit(() -> {
                    try {
                        handleRequest(client, is, os);
                    }//
                    catch (Throwable e) {
                        throw new RuntimeException("there's been an exception in our service: " + e.getMessage());
                    }
                });
            }
        }
    }
}