Solved Something very difficult

Why are you reposting the same post you made a few weeks ago. https://www.spigotmc.org/threads/create-rounds.414425/

 

You can create an event by extending the Event class, https://hub.spigotmc.org/javadocs/spigot/org/bukkit/event/package-summary.html // https://www.spigotmc.org/wiki/using-the-event-api/, which allows you to call an event when a round ends, and start a new one in a listener class right away. vague example code:

Code (Java):

public class RoundEndEvent extends Event {
public RoundEndEvent(/*event parameters*/) {
// etc etc
 

Code (Java):

public class WhereYourRoundEnds {
public void endRound() {
    Bukkit.getServer().getPluginManager().callEvent(new RoundEndEvent(parameters);
    // etc etc etc
}
//etc etc etc
 

Code (Java):

public class RoundEndListener implements Listener {
@EventHandler
public void on(RoundEndEvent e) {
    //start a new round, do whatever (anything that is public in RoundEndEvent can be accessed using e here)
    // etc etc etc
 

Don't forget to register your listeners with Bukkit.getServer().getPluginManager().registerEvents();!