[GUI] on Item Click Open Inventory Error!

Hi Guys!

Im trying to make this plugin, were you can do /shop and then it opens a GUI. When you get in there is some main Menus and when you get into the Main Menus there is Under Menus
I Figured out how open a Under Menu when i click on the first item in a GUI.
But when i use the Exact same code in a new Class and click on the second item it just gives me an error.
Please Help

My under menus are in diffrent classes.

MAIN MENU CODE (Look at the bottom of the code):

Code:

package com.BechGameplay.menuplus;

import java.util.Arrays;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.ItemMeta;
import org.bukkit.plugin.Plugin;

public class mainmenu implements Listener{
   
   
    static Inventory mainmenu;
    private ItemStack Random, Mining, Farming, ByggeBlocks, Redstone, BaseMaterialer, Spawners, PvP, PotionMaterialer, Mad, RaidMaterialer;
   
    public mainmenu(Plugin p) {
        mainmenu = Bukkit.getServer().createInventory(null, 27, ChatColor.DARK_BLUE.toString() + ChatColor.BOLD.toString() +  "=======XENA-SHOP=======");
       
        Mining = Mining(Material.DIAMOND, "Mining Ting");
        Random = Random(Material.STRING, "Random Ting");
        Farming = Farming(Material.WHEAT, "Farming Ting!");
        ByggeBlocks = ByggeBlocks(Material.BRICK, "Bygge Blocks");
        Redstone = Redstone(Material.REDSTONE, "Redstone Materialer");
        BaseMaterialer = BaseMaterialer(Material.BEACON, "Base Materialer");
        Spawners = Spawners(Material.MOB_SPAWNER, "Spawners");
        PvP = PvP(Material.DIAMOND_SWORD, "PvP Ting");
        PotionMaterialer = PotionMaterialer(Material.NETHER_WARTS, "Potion Materialer");
        Mad = Mad(Material.COOKED_BEEF, "Mad");
        RaidMaterialer = RaidMaterialer(Material.TNT, "Raid Materialer");
       
        mainmenu.setItem(0, Mining);
        mainmenu.setItem(2, ByggeBlocks);
        mainmenu.setItem(4, Redstone);
        mainmenu.setItem(6, BaseMaterialer);
        mainmenu.setItem(8, Spawners);
        mainmenu.setItem(10, PvP);
        mainmenu.setItem(12, PotionMaterialer);
        mainmenu.setItem(14, Mad);
        mainmenu.setItem(16, RaidMaterialer);
        mainmenu.setItem(20, Farming);
        mainmenu.setItem(24, Random);
       
       
        Bukkit.getServer().getPluginManager().registerEvents(this, p);
       
    }
    private ItemStack Mining(Material mat, String name) {
        ItemStack i = new ItemStack(Material.DIAMOND, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb dine Mining Ting her!"));
        i.setItemMeta(im);
        return i;
    }
    private ItemStack Random(Material mat, String name) {
        ItemStack i = new ItemStack(Material.STRING, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb dine Random Items her!"));
        i.setItemMeta(im);
        return i;
    }
   
    private ItemStack ByggeBlocks(Material mat, String name) {
        ItemStack i = new ItemStack(Material.BRICK, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb dine Bygge Blocks her!"));
        i.setItemMeta(im);
        return i;
    }
   
    private ItemStack Redstone(Material mat, String name) {
        ItemStack i = new ItemStack(Material.REDSTONE, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb alt dit Redstone her!"));
        i.setItemMeta(im);
        return i;
    }
    private ItemStack BaseMaterialer(Material mat, String name) {
        ItemStack i = new ItemStack(Material.BEACON, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb alt til din Base her!"));
        i.setItemMeta(im);
        return i;
    }
    private ItemStack Spawners(Material mat, String name) {
        ItemStack i = new ItemStack(Material.MOB_SPAWNER, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb Mob-Spawners her!"));
        i.setItemMeta(im);
        return i;
    }
    private ItemStack PvP(Material mat, String name) {
        ItemStack i = new ItemStack(Material.DIAMOND_SWORD, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb PVP Items her!"));
        i.setItemMeta(im);
        return i;
    }
    private ItemStack PotionMaterialer(Material mat, String name) {
        ItemStack i = new ItemStack(Material.GLOWSTONE_DUST, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb alt til Potions her!"));
        i.setItemMeta(im);
        return i;
    }
    private ItemStack Mad(Material mat, String name) {
        ItemStack i = new ItemStack(Material.COOKED_BEEF, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb alt dit Mad her!"));
        i.setItemMeta(im);
        return i;
    }
    private ItemStack RaidMaterialer(Material mat, String name) {
        ItemStack i = new ItemStack(Material.TNT, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb alle dine Raid materialer her!"));
        i.setItemMeta(im);
        return i;
    }
    private ItemStack Farming(Material mat, String name) {
        ItemStack i = new ItemStack(Material.WHEAT, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList("Køb alt til din Baghave her!"));
        i.setItemMeta(im);
        return i;
    }
   
   
   
   
   
   
    public void showmainmenu(Player p){
        p.openInventory(mainmenu);
    }
   
   
    @EventHandler
    public void onInventoryClickE(InventoryClickEvent e) {
        if (!e.getInventory().getName().equalsIgnoreCase(mainmenu.getName())) return;
       
        if(e.getCurrentItem().getItemMeta() == null) return;
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Mining Ting")){
            e.setCancelled(true);

          //THIS WORKS JUST FINE!

            e.getWhoClicked().openInventory(MiningMenu.menu);
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Base Materialer")){
            e.setCancelled(true);
           

              //ITS FAILING HERE! IT CANT OPEN THE MENU
            e.getWhoClicked().openInventory(BaseMenu.menu);
           
        }
       
    }

}

UNDER MENU 1 (THIS ONE WORKS):

Code:

package com.BechGameplay.menuplus;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.ItemMeta;
import org.bukkit.plugin.Plugin;
import org.bukkit.plugin.java.JavaPlugin;

public class MiningMenu implements Listener{
   
   
    static Inventory menu;
    private ItemStack Back, Exit, Diamond, Jern, Guld, DiamondPickaxe, DiamondSkovl;
   
    public MiningMenu(Plugin p) {
        menu = Bukkit.getServer().createInventory(null, 27, ChatColor.DARK_BLUE.toString() + ChatColor.BOLD.toString() +  "=======XENA MINING=======");
       
        Back = Back(Material.MAP, "Tilbage til MainMenu");
        Exit = Exit(Material.SLIME_BALL, "Luk Menuen");
        Diamond = Diamond(Material.DIAMOND, "Diamond - 250,-");
        Jern = Jern(Material.IRON_INGOT, "Jern - 500,-");
        Guld = Guld(Material.WHEAT, "Guld - 1500,-");
        DiamondPickaxe = DiamondPickaxe(Material.BRICK, "Diamond Pickaxe - 800,-");
        DiamondSkovl = DiamondSkovl(Material.REDSTONE, "Diamond Skovl - 300,-");
       
        menu.setItem(21, Back);
        menu.setItem(23, Exit);
        menu.setItem(2, Diamond);
        menu.setItem(0, Jern);
        menu.setItem(4, Guld);
        menu.setItem(6, DiamondPickaxe);
        menu.setItem(8, DiamondSkovl);
       
       
        Bukkit.getServer().getPluginManager().registerEvents(this, p);
       
    }
    private ItemStack Back(Material mat, String name) {
        ItemStack i = new ItemStack(Material.MAP, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
    private ItemStack Exit(Material mat, String name) {
        ItemStack i = new ItemStack(Material.SLIME_BALL, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
    private ItemStack Diamond(Material mat, String name) {
        ItemStack i = new ItemStack(Material.DIAMOND, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
    private ItemStack Jern(Material mat, String name) {
        ItemStack i = new ItemStack(Material.IRON_INGOT, 16);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
   
    private ItemStack Guld(Material mat, String name) {
        ItemStack i = new ItemStack(Material.GOLD_INGOT, 16);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
   
    private ItemStack DiamondPickaxe(Material mat, String name) {
        ItemStack i = new ItemStack(Material.DIAMOND_PICKAXE, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
    private ItemStack DiamondSkovl(Material mat, String name) {
        ItemStack i = new ItemStack(Material.DIAMOND_SPADE, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
   
   
    public void showmainmenu(Player p){
        p.openInventory(menu);
    }
   
   
    @EventHandler
    public void onInventoryClickE(InventoryClickEvent e) {
        if (!e.getInventory().getName().equalsIgnoreCase(menu.getName())) return;
       
        if(e.getCurrentItem().getItemMeta() == null) return;
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Diamond - 250,-")){
            e.setCancelled(true);

            e.getWhoClicked().getInventory().addItem(new ItemStack(Material.DIAMOND, 1));
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Tilbage til MainMenu")){
            e.setCancelled(true);

            e.getWhoClicked().openInventory(mainmenu.mainmenu);
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Jern - 500,-")){
            e.setCancelled(true);

            e.getWhoClicked().getInventory().addItem(new ItemStack(Material.IRON_INGOT, 16));
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Guld - 1500,-")){
            e.setCancelled(true);

            e.getWhoClicked().getInventory().addItem(new ItemStack(Material.GOLD_INGOT, 16));
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Diamond Pickaxe - 800,-")){
            e.setCancelled(true);

            e.getWhoClicked().getInventory().addItem(new ItemStack(Material.DIAMOND_PICKAXE, 1));
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Diamond Skovl - 300,-")){
            e.setCancelled(true);

            e.getWhoClicked().getInventory().addItem(new ItemStack(Material.DIAMOND_SPADE, 1));
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Luk Menuen")){
            e.setCancelled(true);

            e.getWhoClicked().closeInventory();
           
        }
       
    }

}

UNDER MENU 2 (Exact Same code as "Under Menu 1", but it doesent work when im trying to open it, in the main menu):

Code:

package com.BechGameplay.menuplus;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.ItemMeta;
import org.bukkit.plugin.Plugin;

public class BaseMenu implements Listener{
   
   
    static Inventory menu;
    private ItemStack Back, Exit, Diamond, Jern, Guld, DiamondPickaxe, DiamondSkovl;
   
    public BaseMenu(Plugin p) {
        menu = Bukkit.getServer().createInventory(null, 27, ChatColor.DARK_BLUE.toString() + ChatColor.BOLD.toString() +  "=======XENA BASE=======");
       
        Back = Back(Material.MAP, "Tilbage til MainMenu");
        Exit = Exit(Material.SLIME_BALL, "Luk Menuen");
        Diamond = Diamond(Material.DIAMOND, "Diamond - 250,-");
        Jern = Jern(Material.IRON_INGOT, "Jern - 500,-");
        Guld = Guld(Material.WHEAT, "Guld - 1500,-");
        DiamondPickaxe = DiamondPickaxe(Material.BRICK, "Diamond Pickaxe - 800,-");
        DiamondSkovl = DiamondSkovl(Material.REDSTONE, "Diamond Skovl - 300,-");
       
        menu.setItem(21, Back);
        menu.setItem(23, Exit);
        menu.setItem(2, Diamond);
        menu.setItem(0, Jern);
        menu.setItem(4, Guld);
        menu.setItem(6, DiamondPickaxe);
        menu.setItem(8, DiamondSkovl);
       
       
        Bukkit.getServer().getPluginManager().registerEvents(this, p);
       
    }
    private ItemStack Back(Material mat, String name) {
        ItemStack i = new ItemStack(Material.MAP, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
    private ItemStack Exit(Material mat, String name) {
        ItemStack i = new ItemStack(Material.SLIME_BALL, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
    private ItemStack Diamond(Material mat, String name) {
        ItemStack i = new ItemStack(Material.DIAMOND, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
    private ItemStack Jern(Material mat, String name) {
        ItemStack i = new ItemStack(Material.IRON_INGOT, 16);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
   
    private ItemStack Guld(Material mat, String name) {
        ItemStack i = new ItemStack(Material.GOLD_INGOT, 16);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
   
    private ItemStack DiamondPickaxe(Material mat, String name) {
        ItemStack i = new ItemStack(Material.DIAMOND_PICKAXE, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
    private ItemStack DiamondSkovl(Material mat, String name) {
        ItemStack i = new ItemStack(Material.DIAMOND_SPADE, 1);
        ItemMeta im = i.getItemMeta();
        im.setDisplayName(name);
        i.setItemMeta(im);
        return i;
    }
   
   
    public void showmainmenu(Player p){
        p.openInventory(menu);
    }
   
   
    @EventHandler
    public void onInventoryClickE(InventoryClickEvent e) {
        if (!e.getInventory().getName().equalsIgnoreCase(menu.getName())) return;
       
        if(e.getCurrentItem().getItemMeta() == null) return;
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Diamond - 250,-")){
            e.setCancelled(true);

            e.getWhoClicked().getInventory().addItem(new ItemStack(Material.DIAMOND, 1));
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Tilbage til MainMenu")){
            e.setCancelled(true);

            e.getWhoClicked().openInventory(mainmenu.mainmenu);
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Jern - 500,-")){
            e.setCancelled(true);

            e.getWhoClicked().getInventory().addItem(new ItemStack(Material.IRON_INGOT, 16));
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Guld - 1500,-")){
            e.setCancelled(true);

            e.getWhoClicked().getInventory().addItem(new ItemStack(Material.GOLD_INGOT, 16));
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Diamond Pickaxe - 800,-")){
            e.setCancelled(true);

            e.getWhoClicked().getInventory().addItem(new ItemStack(Material.DIAMOND_PICKAXE, 1));
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Diamond Skovl - 300,-")){
            e.setCancelled(true);

            e.getWhoClicked().getInventory().addItem(new ItemStack(Material.DIAMOND_SPADE, 1));
           
        }
        if (e.getCurrentItem().getItemMeta().getDisplayName().contains("Luk Menuen")){
            e.setCancelled(true);

            e.getWhoClicked().closeInventory();
           
        }
       
    }

}

The ERROR:

Code:

[15:45:47 ERROR]: Could not pass event InventoryClickEvent to MenuPlus v1.0
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:299) ~[spigot.jar:git-Spigot-1545]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.jav
a:62) ~[spigot.jar:git-Spigot-1545]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.j
ava:502) [spigot.jar:git-Spigot-1545]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.j
ava:487) [spigot.jar:git-Spigot-1545]
        at net.minecraft.server.v1_7_R4.PlayerConnection.a(PlayerConnection.java
:1434) [spigot.jar:git-Spigot-1545]
        at net.minecraft.server.v1_7_R4.PacketPlayInWindowClick.a(SourceFile:32)
[spigot.jar:git-Spigot-1545]
        at net.minecraft.server.v1_7_R4.PacketPlayInWindowClick.handle(SourceFil
e:10) [spigot.jar:git-Spigot-1545]
        at net.minecraft.server.v1_7_R4.NetworkManager.a(NetworkManager.java:184
) [spigot.jar:git-Spigot-1545]
        at net.minecraft.server.v1_7_R4.ServerConnection.c(ServerConnection.java
:81) [spigot.jar:git-Spigot-1545]
        at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:7
31) [spigot.jar:git-Spigot-1545]
        at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:2
89) [spigot.jar:git-Spigot-1545]
        at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:5
84) [spigot.jar:git-Spigot-1545]
        at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java
:490) [spigot.jar:git-Spigot-1545]
        at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:6
28) [spigot.jar:git-Spigot-1545]
Caused by: java.lang.NullPointerException
        at org.bukkit.craftbukkit.v1_7_R4.entity.CraftHumanEntity.openInventory(
CraftHumanEntity.java:185) ~[spigot.jar:git-Spigot-1545]
        at com.BechGameplay.menuplus.mainmenu.onInventoryClickE(mainmenu.java:16
9) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0
_31]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0
_31]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1
.8.0_31]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_31]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:296) ~[spigot.jar:git-Spigot-1545]
        ... 13 more
>

 

Created something I think might help you:
https://gist.github.com/FerusGrim/712f44e7f7310494502f

 

@BechGameplay Wrong Section. Post this in the bukkit alternatives section

 

I don't think Curse cares about that, all things considered. Spigot is the only 1.8 available download. We expect to see questions for it here.

 

Moved to Bukkit Alternates.

@FerusGrim It is 1.8 which is unofficial so we do care.

 

@FerusGrim Yeah but hes using Spigot 1.8 =and they have made a special section in this forum for spigot/couldron,...