Solved How come it returns to me null

Hi everyone, I need a hand in understanding why this code returns a nullPointer even though it doesn't seem like it can

this the errror:

Code:

Caused by: java.lang.NullPointerException
        at org.salex.pvpsword.events.SwordEvent.onCambioItem(SwordEvent.java:41) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_292]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_292]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_292]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_292]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot.jar:git-Spigot-db6de12-18fbb24

and this is my class:

Code:

package org.salex.pvpsword.events;

import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerItemHeldEvent;
import org.bukkit.inventory.ItemStack;
import org.salex.pvpsword.Main;


public class SwordEvent implements Listener {
   
    private Main main;
    private List<UUID> pvp;
    private ItemStack[] armor;
    private ItemStack[] armor1;
   
    public SwordEvent(Main m) {
        main = m;
        this.pvp = new ArrayList<UUID>();
        this.armor = new ItemStack[4];
        this.armor1 = new ItemStack[4];
    }
   
   
    @EventHandler
    public void onCambioItem(PlayerItemHeldEvent event) {
        Player p = event.getPlayer();
        armor[3] = (new ItemStack(Material.DIAMOND_HELMET));
        armor[2] = (new ItemStack(Material.DIAMOND_CHESTPLATE));
        armor[1] = (new ItemStack(Material.DIAMOND_LEGGINGS));
        armor[0] = (new ItemStack(Material.DIAMOND_BOOTS));
       
        String nome = main.getConfig().getString("sword.name");
       
        if(p.getPlayer().getItemInHand().getItemMeta().getDisplayName().equals(nome) && !pvp.contains(p.getUniqueId())) {
            p.getInventory().setArmorContents(armor);
            pvp.add(p.getUniqueId());
        } else if (!p.getPlayer().getItemInHand().getItemMeta().getDisplayName().equals(nome)  && pvp.contains(p.getUniqueId())) {
            p.getInventory().setArmorContents(armor1);
            pvp.remove(p.getUniqueId());
        }
    }
   
    public List<UUID> getPvp() {
        return pvp;
    }
   
    public ItemStack[] getArmor() {
        return armor;
    }
   
}

anyone know why?

 

It's because Player#getItemInHand() returns null if they aren't holding anything, and so it causes an error because it can't get attributes such as item meta. It's simple to combat this, just add:

Code:

ItemStack item = //Player#getItemInHand();
if (item != null && !item.getType().equals(Material.AIR)) {
    //code
}