import io.vertx.core.AbstractVerticle; public class Server extends AbstractVerticle { public void start() { vertx.createHttpServer().requestHandler(req -> { req.response() .putHeader("content-type", "text/plain") .end("Hello from Vert.x!"); }).listen(8080); } } import io.vertx.core.AbstractVerticle class Server : AbstractVerticle() { override fun start() { vertx.createHttpServer().requestHandler {