Fajen klase

package pl.meleride.api.user.manager;

import org.apache.commons.lang.Validate;
import org.bukkit.Bukkit;
import org.bukkit.entity.Player;
import pl.meleride.api.user.User;

import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.stream.Collectors;
import pl.meleride.api.user.UserImpl;

public class UserManagerImpl implements UserManager {

  private final ConcurrentMap<String, User> userNameMap = new ConcurrentHashMap<>(16, 0.9F, 1);
  private final ConcurrentMap<UUID, User> userUniqueIdMap = new ConcurrentHashMap<>(16, 0.9F, 1);

  @Override
  public Optional<User> getUser(String name) {
    Validate.notNull(name, "Player name cannot be null!");

    return this.userNameMap.values()
        .stream()
        .filter(user -> user.getName().equalsIgnoreCase(name))
        .findFirst();
  }

  @Override
  public Optional<User> getUser(UUID uniqueId) {
    Validate.notNull(uniqueId, "Player unique id cannot be null!");

    return this.userUniqueIdMap.values()
        .stream()
        .filter(user -> user.getUniqueId().equals(uniqueId))
        .findFirst();
  }

  @Override
  public Optional<User> getUser(Player player) {
    Validate.notNull(player, "Player object cannot be null!");

    return this.getUser(player.getUniqueId());
  }

  @Override
  public void addUser(User user) {
    Validate.notNull(user, "User object cannot be null!");

    this.userUniqueIdMap.put(user.getUniqueId(), user);
    this.userNameMap.put(user.getName(), user);
  }

  @Override
  public void createUser(Player player) {
    Validate.notNull(player, "Player cannot be null!");

    User user = new UserImpl(player);
    this.userUniqueIdMap.put(user.getUniqueId(), user);
    this.userNameMap.put(player.getName(), user);
  }

  @Override
  public void createUser(UUID uuid) {
    Validate.notNull(uuid, "UUID of player cannot be null!");

    User user = new UserImpl(uuid);
    this.userUniqueIdMap.put(uuid, user);
    this.userNameMap.put(Bukkit.getPlayer(uuid).getName(), user);
  }

  @Override
  public void removeUser(User user) {
    Validate.notNull(user, "User object cannot be null!");

    this.userUniqueIdMap.remove(user.getUniqueId());
    this.userNameMap.remove(user.getName());
  }

  @Override
  public Set<User> getOnlineUsers() {
    return Bukkit.getServer().getOnlinePlayers().stream()
      .map(player -> this.getUser(player.getUniqueId()))
      .filter(Optional::isPresent)
      .map(Optional::get)
      .collect(Collectors.toCollection(LinkedHashSet::new));
  }

}


/ ------------------------------------------------------------------------ \

package pl.meleride.api.user.caller;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.UUID;
import org.bukkit.Bukkit;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.EventPriority;
import org.bukkit.event.Listener;
import org.bukkit.event.player.AsyncPlayerPreLoginEvent;
import pl.meleride.api.MelerideAPI;
import pl.meleride.api.storage.StorageException;
import pl.meleride.api.storage.sql.hikari.SQLHikariStorage;
import pl.meleride.api.user.User;
import pl.meleride.api.user.event.UserAbortEvent;
import pl.meleride.api.user.event.UserInitEvent;
import pl.meleride.api.user.manager.UserManager;
import pl.meleride.api.user.manager.UserManagerImpl;
import pl.meleride.api.user.status.DiseaseStatus;

public class PlayerPreLoginListener implements Listener {

  private MelerideAPI instance;
  private UserManager userManager = new UserManagerImpl();
  private ResultSet resultSet;

  public PlayerPreLoginListener(MelerideAPI instance) {
    this.instance = instance;
  }

  @EventHandler(priority = EventPriority.LOWEST)
  public void onPlayerPreLogin(AsyncPlayerPreLoginEvent event) {
    Player player = Bukkit.getPlayer(event.getUniqueId());
    if(!this.userManager.getUser(player).isPresent()) {
      this.userManager.createUser(player);
    }
    User user = this.userManager.getUser(player).get();
    SQLHikariStorage storage = instance.getStorage();

    UserInitEvent userInitEvent = new UserInitEvent(user);
    Bukkit.getPluginManager().callEvent(userInitEvent);

    if (userInitEvent.isCancelled()) {
      UserAbortEvent userAbortEvent = new UserAbortEvent(user);
      Bukkit.getPluginManager().callEvent(userAbortEvent);
      event.disallow(AsyncPlayerPreLoginEvent.Result.KICK_OTHER, "Session abort.");
      return;
    }

    this.userManager.addUser(user);

    try {
      resultSet = storage.query("SELECT " + event.getName() + " from users");
        user.setName(resultSet.getString("name"));
        for(DiseaseStatus disease : DiseaseStatus.getDiseaseFromString(resultSet.getString("disease").split(","))) {
          user.addDisease(disease);
        }
    } catch(StorageException | SQLException e) {
      Bukkit.getLogger().severe("Wystąpił BARDZO POTEŻNY błąd w ładowaniu gracza!!1");
      e.printStackTrace();
    }
  }

}