How to make subclasses unique

Hello People,
I'm working at a little Test for a SpLaG plugin.

So I made a Class for the shovel and another one for the egg(the projectile, not the Item).
My idea was, that when you do a rightclick with the shovel an egg should be fired, and the hitted Block disappears.
Unfortunately it's don't working and I think it's because the Server can't

distinguish my SpLaG shovel from a normal one.
That's how it looks like

Code:java

//SpLaGSpade.java
public class SplagSpade extends ItemStack{
    public SplagSpade(){
        this.setType(Material.DIAMOND_SPADE);
        this.setDurability((short) 50000);
        getItemMeta().setDisplayName("SplagSpade");
        this.addEnchantment(Enchantment.DURABILITY, 1);
        this.setAmount(1);
    }
}

In fact there aren't any differences.

So the question stands in the title.
How to make this classes unique?

 

You can use the instanceof operator to check class type in Java.

Code:

if(someitemstack instanceof SplagSpade) {
}

Be careful though, this does return true for superclasses - so (mysplagspade instanceof ItemStack) is true.

 

Actually I already done that.
I just forgot to mention it. Sorry
MultipleListener.java:

Code:java

    @EventHandler
    public void SpadeFireListener(PlayerInteractEvent e){
      if(e.getPlayer().getItemInHand()instanceof SplagSpade){
          e.getPlayer().launchProjectile(SplagEgg.class);
      }
    }
 
    @EventHandler
    public void EggCollision(ProjectileHitEvent e){
        if(e.getEntity() instanceof SplagEgg){
            e.getEntity().getLocation().getBlock().setType(Material.AIR);
        }
    }

Oh. And the problem is, that the spade didn't even launch the egg.