NullPointerExeption

Whenever I have an item held with my cursor within the crafting screen and throw it outside of the crafting menu (Dropping the item on the floor) It shows up with this error:

Code:

[20:27:58] [Server thread/ERROR]: Could not pass event InventoryClickEvent to SurvivalServer v1.045
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:294) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:1361) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at net.minecraft.server.v1_7_R1.PacketPlayInWindowClick.a(SourceFile:32) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at net.minecraft.server.v1_7_R1.PacketPlayInWindowClick.handle(SourceFile:10) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
Caused by: java.lang.NullPointerException
    at me.DiamGamingWTF.SS.ToolCrafting.WoodTools.onInteract(WoodTools.java:45) ~[?:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_40]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_40]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_40]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_40]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3023jnks]
    ... 13 more

This is the code I am currently using;

Code:java

 
 
 
import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.enchantments.Enchantment;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.event.inventory.PrepareItemCraftEvent;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.ItemMeta;
 
public class WoodTools implements Listener {
 
@EventHandler
public void onCraft(PrepareItemCraftEvent event){
 
if(event.getInventory().getResult().getType() == Material.WOOD_PICKAXE){
ItemStack WoodPickaxe = new ItemStack(Material.WOOD_PICKAXE, 1);
ItemMeta i = WoodPickaxe.getItemMeta();
i.setDisplayName(ChatColor.GOLD + "Wooden Pickaxe");
WoodPickaxe.setItemMeta(i);
WoodPickaxe.addUnsafeEnchantment(Enchantment.DURABILITY, 1);
 
event.getInventory().setResult(WoodPickaxe);
return;
}
}
 
@EventHandler
public void onInteract(final InventoryClickEvent e) {
ItemStack WoodPickaxe = new ItemStack(Material.WOOD_PICKAXE, 1);
ItemMeta i = WoodPickaxe.getItemMeta();
i.setDisplayName(ChatColor.GOLD + "Wooden Pickaxe");
WoodPickaxe.setItemMeta(i);
WoodPickaxe.addUnsafeEnchantment(Enchantment.DURABILITY, 1);
 
final ItemStack WoodPickaxe2 = new ItemStack(Material.STONE_AXE, 1);
 
if (e.getCursor() == null) {
return;
}
 
if (e.getCurrentItem().equals(WoodPickaxe)) {
e.setCurrentItem(WoodPickaxe2);
return;
}
}
 
}
 

I have tried checking if the item quantity in the cursor was 0 DIDNT WORK
I have tried checking if the item is null DIDNT WORK
I have tried setting the item to null.. Just changes all items to null when i click something..

Please help me, thank you for reading this


PS. The code works fine.. it just shows up with the null pointer when clicking outside the Crafting GUI

 

e.getCurrentItem() will return null, you can prevent this with a null check. Also, learn to read stacktraces

 

Sgt_Tailor
Yea.. i suck at stacktraces.. and I have no idea how to perform a null check because I don't regularly get NullPointers

 

this should do the trick
if(e.getCurrentItem() != null && e.getCurrentItem().equals(WoodPickaxe)){

}