Server.java

import java.io.IOException;
import java.io.OutputStream;
import java.net.InetSocketAddress;

import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;

public class Server {

    public static void main(String[] args) throws Exception {

        HttpServer server = HttpServer.create(new InetSocketAddress(8080), 0);

        server.createContext("/", new HttpHandler() {

            @Override
            public void handle(HttpExchange t) throws IOException {

                String response = "Hello World!";
                t.sendResponseHeaders(200, response.length());
                OutputStream os = t.getResponseBody();
                os.write(response.getBytes());
                os.close();
            }
        });

        server.start();
    }
}