Почему оно не работает?

 import com.google.gson.Gson; 
import org.bukkit.entity.Player; 
import org.bukkit.event.EventHandler; 
import org.bukkit.event.Listener; 
import org.bukkit.event.player.PlayerJoinEvent; 
import org.bukkit.event.player.PlayerQuitEvent; 
import org.bukkit.plugin.java.JavaPlugin; 
 
import java.io.IOException; 
import java.util.Arrays; 
import java.util.Base64; 
import java.util.UUID; 
 
import InventoryGet.*; 
 
public class InventorySync extends JavaPlugin implements Listener { 
    String saveInv = "192.168.137.38:4443/saveInv.php"; 
    String loadInv = "192.168.137.38:4443/loadInv.php"; 
    Gson gson = new Gson(); 
    @EventHandler 
    public void onJoin(PlayerJoinEvent event) throws IOException { 
        Player player = event.getPlayer(); 
        UUID uuid = player.getUniqueId(); 
        //InventoryGet.main(loadInv + "?username=" + uuid.toString()); 
    } 
 
    @EventHandler 
    public void onQuit(PlayerQuitEvent event) throws IOException { 
        Player player = event.getPlayer(); 
        UUID uuid = player.getUniqueId(); 
        Object[] contents = Arrays.stream(player.getInventory().getContents()).toArray(); 
        String inv = Base64.getEncoder().encodeToString( gson.toJson(contents).getBytes() ); 
        InventoryGet.main(saveInv + "?username=" + uuid.toString() + "&inventory=" + inv); 
        System.out.print("123"); 
    } 
}