How to use

getSaveLoader

method

in

net.minecraft.world.storage.ISaveFormat

/**
 * Requires to start up from external from here
 *
 * drawback of the singleton build style
 *
 * @param server
 */
public static void onServerAboutToStart( MinecraftServer server )
{
  File worldDirectory = DimensionManager.getCurrentSaveRootDirectory();
  if( worldDirectory == null )
  {
    worldDirectory = server.getActiveAnvilConverter().getSaveLoader( server.getFolderName(), false ).getWorldDirectory();
  }
  final WorldData newInstance = new WorldData( worldDirectory );
  instance = newInstance;
  newInstance.onServerStarting();
}