NPE

Hello Everyone,

I am getting an NPE and I don't know why.
Error:

Code:

[17:30:40] [Server thread/ERROR]: Could not pass event InventoryClickEvent to Quidditch v1.0
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:320) ~[Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:486) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:471) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:1361) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.PacketPlayInWindowClick.a(SourceFile:32) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.PacketPlayInWindowClick.handle(SourceFile:10) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
Caused by: java.lang.NullPointerException
    at me.pieman.quidditch.Quidditch.onInventoryClick(Quidditch.java:91) ~[?:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_45]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_45]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_45]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_45]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:318) ~[Craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    ... 13 more
[17:35:33]

InventoryClickEvent:

Code:java

    @EventHandler
    public void onInventoryClick(InventoryClickEvent e){
        Player p = (Player) e.getWhoClicked();
        p.sendMessage("Working!!!");
        if(!e.getInventory().getName().equalsIgnoreCase(inv.getName())) return;
        p.sendMessage("Working");
        if(e.getCurrentItem() == null) return;
        p.sendMessage("Still Working");
        if(e.getCurrentItem().getItemMeta().getDisplayName().equalsIgnoreCase("gryffindor")){
            e.setCancelled(true);
            Bukkit.getServer().broadcastMessage(ChatColor.DARK_AQUA+"[" + ChatColor.AQUA + "AG Quidditch" + ChatColor.DARK_AQUA + "] " + p.getName() + " has joined Gryffindor!");
            p.closeInventory();
            p.sendMessage("Should Be Working");
        }

Whole Class:

Code:java

package me.pieman.quidditch;
 
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
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.java.JavaPlugin;
 
public class Quidditch extends JavaPlugin implements Listener{
 
    private Inventory inv;
 
    public void onEnable(){
        Bukkit.getServer().getPluginManager().registerEvents(this, this);
    }
 
    @SuppressWarnings("deprecation")
    public void open(Player p){
        inv = Bukkit.createInventory(null, 9, "Teams");
 
        ItemStack red = new ItemStack(Material.WOOL, 1, (byte) 14);
        ItemMeta redmeta = red.getItemMeta();
        redmeta.setDisplayName(ChatColor.RED+"Gryffindor");
        red.setItemMeta(redmeta);
 
        ItemStack yellow = new ItemStack(Material.WOOL, 1, (byte) 4);
        ItemMeta yellowmeta = yellow.getItemMeta();
        yellowmeta.setDisplayName(ChatColor.YELLOW+"Hufflepuff");
        yellow.setItemMeta(yellowmeta);
 
        ItemStack blue = new ItemStack(Material.WOOL, 1, (byte) 11);
        ItemMeta bluemeta = blue.getItemMeta();
        bluemeta.setDisplayName(ChatColor.DARK_BLUE+"Ravenclaw");
        blue.setItemMeta(bluemeta);
 
        ItemStack green = new ItemStack(Material.WOOL, 1, (byte) 13);
        ItemMeta greenmeta = green.getItemMeta();
        greenmeta.setDisplayName(ChatColor.GREEN+"Slytherin");
        green.setItemMeta(greenmeta);
 
        inv.clear();
        inv.setItem(3, new ItemStack(red));
        inv.setItem(4, new ItemStack(yellow));
        inv.setItem(5, new ItemStack(blue));
        inv.setItem(6, new ItemStack(green));
 
        p.openInventory(inv);
        p.updateInventory();
    }
 
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args){
        if(label.equalsIgnoreCase("quidditch")){
            if(args.length == 0){
                sender.sendMessage(ChatColor.RED + "Wrong usage /quidditch join");
                return true;
            }
            if(!(sender instanceof Player)){
                sender.sendMessage(ChatColor.RED + "Only players can use the command!");
                return true;
            }
            Player p = (Player) sender;
            if(args[0].equalsIgnoreCase("join")){
                if(p.hasPermission("quidditch.play")){
                    open(p);
                    return true;
                } else {
                    p.sendMessage(ChatColor.RED + "Sorry you do not have permission!");
                    return true;
                }
            }
        }
        return true;
    }
 
    @EventHandler
    public void onInventoryClick(InventoryClickEvent e){
        Player p = (Player) e.getWhoClicked();
        p.sendMessage("Working!!!");
        if(!e.getInventory().getName().equalsIgnoreCase(inv.getName())) return;
        p.sendMessage("Working");
        if(e.getCurrentItem() == null) return;
        p.sendMessage("Still Working");
        if(e.getCurrentItem().getItemMeta().getDisplayName().equalsIgnoreCase("gryffindor")){
            e.setCancelled(true);
            Bukkit.getServer().broadcastMessage(ChatColor.DARK_AQUA+"[" + ChatColor.AQUA + "AG Quidditch" + ChatColor.DARK_AQUA + "] " + p.getName() + " has joined Gryffindor!");
            p.closeInventory();
            p.sendMessage("Should Be Working");
        }
        if(e.getCurrentItem().getItemMeta().getDisplayName().equalsIgnoreCase("hufflepuff")){
            e.setCancelled(true);
            Bukkit.getServer().broadcastMessage(ChatColor.DARK_AQUA+"[" + ChatColor.AQUA + "AG Quidditch" + ChatColor.DARK_AQUA + "] " + p.getName() + " has joined Hufflepuff!");
            p.closeInventory();
        }
        if(e.getCurrentItem().getItemMeta().getDisplayName().equalsIgnoreCase("ravenclaw")){
            e.setCancelled(true);
            Bukkit.getServer().broadcastMessage(ChatColor.DARK_AQUA+"[" + ChatColor.AQUA + "AG Quidditch" + ChatColor.DARK_AQUA + "] " + p.getName() + " has joined Ravenclaw!");
            p.closeInventory();
        }
        if(e.getCurrentItem().getItemMeta().getDisplayName().equalsIgnoreCase("slytherin")){
            e.setCancelled(true);
            Bukkit.getServer().broadcastMessage(ChatColor.DARK_AQUA+"[" + ChatColor.AQUA + "AG Quidditch" + ChatColor.DARK_AQUA + "] " + p.getName() + " has joined Slytherin!");
            p.closeInventory();
        }
    }
 
}
 

Line 91:

Code:java

if(e.getCurrentItem().getItemMeta().getDisplayName().equalsIgnoreCase("gryffindor")){

 

PieMan456
Check if getCurrentItem returns null. It could also be getItemMeta

 

SuperOmegaCow
I am testing that. The debug lines go to "Still Working". It works through "Working!!!" "Working" but it stops at "Still Working".

 

PieMan456 does it get to Should be working?

 

PieMan456
It might be that the item's display name returns null o.o

 

If the item has no ItemMeta it will return null, hence your NPE. Check first:

Code:java

if (ItemStack.hasItemMeta()) {
    // can use .getItemMeta()
} else {
    // is null
}

 

1Rogue alex123099 SuperOmegaCow
I assign a name to it though so how would it be null?

Code:java

ItemStack red = new ItemStack(Material.WOOL, 1, (byte) 14);
        ItemMeta redmeta = red.getItemMeta();
        redmeta.setDisplayName(ChatColor.RED+"Gryffindor");
        red.setItemMeta(redmeta);

1Rogue
It does return null so how would I fix this?

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

He showed you in his post, check hasItemMeta first.

 

PieMan456 you only assign this data when the player actually types the command.

 

SuperOmegaCow Alshain01
Well obviously checking the item meta is not working for me so is there a way to check if the item they're clicking on is red wool?

is there a way to check if the item they're clicking on is red wool?

EDIT by Moderator: merged posts, please use the edit button instead of double posting.