HttpServer from JDK since 1.6

WebApp.java

import java.io.OutputStream;
import java.net.InetSocketAddress;
import com.sun.net.httpserver.HttpServer;

public class WebApp {

    public static void main(String[] args) throws Exception {
        HttpServer server = HttpServer.create(new InetSocketAddress(9394), 0);
        server.createContext("/ping").setHandler(h -> {
            final String response = "pong!";
            h.sendResponseHeaders(200, response.getBytes().length);
            try (OutputStream os = h.getResponseBody()) {
                os.write(response.getBytes());
            }
        });
        server.createContext("/shutdown").setHandler(h -> server.stop(0));
        server.start();
    }
}