content: package net.minecraft.server.management;
  
  import com.google.common.base.Predicate;
  import com.google.common.collect.Iterators;
  import com.google.common.collect.Lists;
  import com.mojang.authlib.Agent;
  import com.mojang.authlib.GameProfile;
  import com.mojang.authlib.ProfileLookupCallback;
  import net.minecraft.entity.player.EntityPlayer;
  import net.minecraft.server.MinecraftServer;
  import net.minecraft.util.StringUtils;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  
  import java.io.File;
  import java.util.Collection;
  import java.util.List;
  import java.util.UUID;
  
  public class PreYggdrasilConverter {
      private static final Logger LOGGER = LogManager.getLogger();
      public static final File OLD_IPBAN_FILE = new File("banned-ips.txt");
      public static final File OLD_PLAYERBAN_FILE = new File("banned-players.txt");
      public static final File OLD_OPS_FILE = new File("ops.txt");
      public static final File OLD_WHITELIST_FILE = new File("white-list.txt");
  
      private static void lookupNames(MinecraftServer server, Collection<String> names, ProfileLookupCallback callback) {
          String[] astring = Iterators.toArray(Iterators.filter(names.iterator(), new Predicate<String>() {
              public boolean apply(String p_apply_1_) {
                  return !StringUtils.isNullOrEmpty(p_apply_1_);
              }
          }), String.class);
  
          if (server.isServerInOnlineMode()) {
              server.getGameProfileRepository().findProfilesByNames(astring, Agent.MINECRAFT, callback);
          } else {
              for (String s : astring) {
                  UUID uuid = EntityPlayer.getUUID(new GameProfile(null, s));
                  GameProfile gameprofile = new GameProfile(uuid, s);
                  callback.onProfileLookupSucceeded(gameprofile);
              }
          }
      }
  
      public static String getStringUUIDFromName(String p_152719_0_) {
          if (!StringUtils.isNullOrEmpty(p_152719_0_) && p_152719_0_.length() <= 16) {
              final MinecraftServer minecraftserver = MinecraftServer.getServer();
              GameProfile gameprofile = minecraftserver.getPlayerProfileCache().getGameProfileForUsername(p_152719_0_);
  
              if (gameprofile != null && gameprofile.getId() != null) {
                  return gameprofile.getId().toString();
              } else if (!minecraftserver.isSinglePlayer() && minecraftserver.isServerInOnlineMode()) {
                  final List<GameProfile> list = Lists.newArrayList();
                  ProfileLookupCallback profilelookupcallback = new ProfileLookupCallback() {
                      public void onProfileLookupSucceeded(GameProfile p_onProfileLookupSucceeded_1_) {
                          minecraftserver.getPlayerProfileCache().addEntry(p_onProfileLookupSucceeded_1_);
                          list.add(p_onProfileLookupSucceeded_1_);
                      }
  
                      public void onProfileLookupFailed(GameProfile p_onProfileLookupFailed_1_, Exception p_onProfileLookupFailed_2_) {
                          PreYggdrasilConverter.LOGGER.warn("Could not lookup user whitelist entry for " + p_onProfileLookupFailed_1_.getName(), p_onProfileLookupFailed_2_);
                      }
                  };
                  lookupNames(minecraftserver, Lists.newArrayList(p_152719_0_), profilelookupcallback);
                  return list.size() > 0 && list.get(0).getId() != null ? list.get(0).getId().toString() : "";
              } else {
                  return EntityPlayer.getUUID(new GameProfile(null, p_152719_0_)).toString();
              }
          } else {
              return p_152719_0_;
          }
      }
  }
  