Solved ItemMeta causing NPE...

It seems the the past few builds I've been using to develop with (all latest dev builds), contain an NPE using ItemMeta..

Perhaps it could be that i'm using colored names with the § symbol (section), as opposed to using another method..

Here's an example of code causing a questioning NPE

Code:

ItemStack is = new ItemStack(Material.DIAMOND_SWORD, 1);
ItemMeta meta = is.getItemMeta();
meta.setDisplayName("§5 I am purple ");
is.setItemMeta(meta);

NPE will be thrown, saying error on the 3rd line (set display name).. item stack isn't null, however the meta some how is..


Is this changed?

 

getItemMeta() will return null if there is no ItemMeta. you need to create a new ItemMeta instance w/ getServer().getItemFactory().getItemMeta(Material);

I stand corrected.

 

Well, it would be null because .getItemMeta(); is returning null. I haven't worked much with ItemMeta personally, but could you just check if that returned null, and if it did initialize it with a new value?

Could it not have ItemMeta because it's merely a new ItemStack in the first place?

Try creating a new instance of meta and setting that, instead of grabbing from the ItemStack.

 

1Rogue
Never do new ItemMeta(), because that gives also an error.

 

I haven't made a plugin in so long! I didn't even know there was an item factory you had to use... Thanks!

 

I dont think you need it for anything other than creating new ItemMeta instances to be honest. I've never found another use for it.

 

You cannot create direct instances of interfaces anyhow, you would need to go through ItemFactory.

 

Just wondering if anyone knows when this changed?

I used to have no issues at all using the method above..

And still getting an NPE when using .getItemMeta() in ItemFactory

Edit: It only appears when setting lore+display name..

 

That isn't true. If the itemstack's ItemMeta is null it attempts to create a new one when you call the getItemMeta() on that ItemStack: HERE. The only time it is null is if the chosen material is air: HERE. I don't know why in this instance that would be the case but I'm guessing it's probably because that isn't the actual code that is being used.

 

Current code being used exactly:

Code:java

 
 
    public void createMenus()
    {
        //!f
        shopMenu = new IconMenu("§5Shop", 9 * 4, new IconMenu.OptionClickEventHandler()
        {
            @Override
            public void onOptionClick(OptionClickEvent event)
            {
                switch (event.getPosition())
                {
 
                }
                event.setWillClose(true);
            }
        }, this)
        .setOption(0, configData.getShopItem(Upgrade.C4), "§cC4", "test")
        .setOption(1, configData.getShopItem(Upgrade.GRENADE_FRAG), "§cFrag Grenade", "test")
        .setOption(2, configData.getShopItem(Upgrade.GRENADE_CLUSTER), "§cCluster Grenade", "test")
        .setOption(3, configData.getShopItem(Upgrade.LANDMINE), "§cLandmine", "test")
        .setOption(4, configData.getShopItem(Upgrade.HARRIERS), "§cHarrier Strike", "test")
        .setOption(5, configData.getShopItem(Upgrade.GRENADE_FLASHBANG), "§cFlashbang", "test")
        .setOption(6, configData.getShopItem(Upgrade.RIOTSHIELD), "§cRiot Shield", "test")
        .setOption(7, configData.getShopItem(Upgrade.ROCKETLAUNCHER), "§cRocket Launcher (1)", "test")
        ;
        //f
    }
 

And nisovin's Iconmenu class.. in particular, this method

Code:java

 
 
    private ItemStack setItemNameAndLore(ItemStack item, String name, String[] lore)
    {
        ItemStack is = item.clone();
        ItemMeta im = item.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList(lore));
        item.setItemMeta(im);
        return is;
    }
 
Not sure if it will make sense, but restarting my IDE seemed to fix the issue..
 
EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Thanks for correcting me. I could have swore I've had getItemMeta return null on me many times, but I must be mistaken.

 

TheGreenGamerHD
Turn this:

Code:java

private ItemStack setItemNameAndLore(ItemStack item, String name, String[] lore)
    {
        ItemStack is = item.clone();
        ItemMeta im = item.getItemMeta();
        im.setDisplayName(name);
        im.setLore(Arrays.asList(lore));
        item.setItemMeta(im);
        return is;
    }

To this:

Code:java

private ItemStack setItemNameAndLore(ItemStack item, String name, String[] lore)
    {
        ItemStack is = item;
ItemMeta im = item.getItemMeta();
im.setDisplayName(name);
im.setLore(Arrays.asList(lore));
is.setItemMeta(im);
return is;
    }

You made a little mistake:
"item.setItemMeta(im);" - But you want to return is

KingNyuels

 

In that method, if you send in an itemstack of air it would throw that error. It looks like you are getting all of your item ids from a config file though, so if you are attempting to retrieve an integer from a non-existant (maybe spelled wrong) path I believe it will return 0 which might be the problem. It's also possible that it's set to 0 in the config file. If that isn't the problem then check to make sure that the 'configData.getShopItem(Upgrade.****)' doesn't return 0 for any of the values.