Now, I begin to learn vert.x.
At first, I tried to define a function that can work.
However, my current implementation gives me the following error: when I run the program for the second time
 22, 2018 3:29:23  io.vertx.core.http.impl.HttpServerImpl
: java.net.BindException: Address already in use
I hope that when I run the second time, I can first detect the port, and if the port is occupied, close the port first
I could not find an answer from the documentation.
< H1 > Source code < / H1 >package com.project.service;
import io.vertx.core.AbstractVerticle;
import io.vertx.core.Vertx;
import io.vertx.core.VertxOptions;
import io.vertx.ext.web.Router;
import java.util.function.Consumer;
public class VerticleMain extends AbstractVerticle {
    @Override
    public void start() throws Exception {
        Router router = Router.router(vertx);
        router.route().handler(routingContext -> {
            routingContext.response()
                    .putHeader("content-type","text/html;charset=UTF-8")
                    .end("");
        });
        vertx.createHttpServer().requestHandler(router::accept).listen(8181);
    }
    public static void deployVertx() {
        String verticleId = VerticleMain.class.getName();
        VertxOptions options = new VertxOptions();
        Consumer<Vertx> runner = vertxStart -> {
            vertxStart.deployVerticle(verticleId);
        };
        Vertx vertx = Vertx.vertx(options);
        runner.accept(vertx);
    }
    public static void main(String[] args) {
        VerticleMain.deployVertx();
    }
}
						