Problem in my Bukkit plugin

I'm trying to create a command that heals you but you have to pay 1 gold nugget.

Ingame it works fine when you have a gold nugget, but if you have not a gold nugget it's an internal error.
How can i fix that?

Code:

if (cmd.getName().equalsIgnoreCase("heal")) {

            for(int i = 0; i<p.getInventory().getSize()-1; ++i) {
                if(p.getInventory().getItem(i).getType() == Material.GOLD_NUGGET){
                    p.getInventory().remove(new ItemStack(org.bukkit.Material.GOLD_NUGGET, 1));
                p.sendMessage("§4Healed");
                p.playSound(p.getLocation(), Sound.VILLAGER_YES, 10, 1);
                p.setHealth(20);
                p.setFoodLevel(20);
                p.setSaturation(20);
                return true;
            } else {
                p.sendMessage("§6You don't have a gold nugget");
                p.playSound(p.getLocation(),Sound.WITHER_HURT, 10 ,1);
                return true;

                }

            }

 

@timtower What do you mean (sorry im new in programming plugins)

 

so i don't know how to edit the code because im such a noob

Sorry im confused

 

give me 5 minutes to test

I did this:

Code:

for (int i = 0; i < p.getInventory().getSize() - 1; ++i) {
                if (p.getInventory().getItem(i).getType() == Material.AIR) {
                    p.sendMessage("§6You don't have a gold nugget");
                    p.playSound(p.getLocation(), Sound.WITHER_HURT, 10, 1);
                    return true;
                } else {
                    p.getInventory().remove(new ItemStack(Material.GOLD_NUGGET, 1));
                    p.sendMessage("§4Healed");
                    p.playSound(p.getLocation(), Sound.VILLAGER_YES, 10, 1);
                    p.setHealth(20);
                    p.setFoodLevel(20);
                    p.setSaturation(20);
                    return true;

I think i didn't understand it correct because it's the same error ingame when i have no nugget

there's also an error in console. Im getting null error: org.bukkit.command.CommandException: Unhandled exception executing command 'heal' in plugin test v1.0

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

 

yea i know but how can i do a null check

i tried something like that : Playerinventory inv = p.getInventory().getItem(i).getType() == MATERIAL.GOLDNUGGET
if(inv == null)

but this didn't work either

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

 

yes, im only getting things that my program don't like

 

I don't know how

I fixed it with
if(p.getInventory().contains(Material.GOLD_NUGGET))

TY for your time

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