No me funciona

Buenas tardes, Sigo las instrucciones del video y no me funciona, me sigue apareciendo la misma pantalla del localhost:8080 y del localhost:8080/hello

package med.voll.api.controller;

import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController;

@RestController @RequestMapping("hello") public class HelloController {

@GetMapping
public String helloworld() {
    System.out.println("desde controller...");
    return "Hello world!";
}

}

package med.voll.api;

import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication public class ApiApplication {

public static void main(String[] args) {
    //System.out.println("Hola API!!!");
    SpringApplication.run(ApiApplication.class, args);
}

}