GUI plugin

I want to make a GUI plugin that opens a GUI when you click with a chest in your hand. There should be 4 things in the chest:
- Spawn --> Tps to spawn
- Rules --> Sends the player all the rules
- Doneren --> The player does /buy
- Map --> Gives the player a map and if he scrolls away it disapears
The last 2 do not work.
On Inventory Click:
http://pastebin.com/xv5aA6ba
Console:
http://pastebin.com/aChY0d99
How can I fix this?
Thanks

 

Fix line 110, and follow naming conventions.

 

What do you mean with "fix"?

 

@BakedPotato_HD
If you actually read your error report, which you can learn how here:
http://bukkit.org/threads/how-to-re...ubleshoot-your-own-plugins-by-yourself.32457/
You would know that line 110 is null.

 

@Zombie_Striker But how can I fix it so it isn't null anymore?
Thanks

 

@BakedPotato_HD
If you do not know how to null check, you should not be coding. Bukkit requires knowledge of Java. Read this before you continue:
http://bukkit.org/threads/plugin-dev-sticky-learning-java-where-to-learn.350132/

 

@Zombie_Striker Sorry for me being a noob, but I don't understand what a NullPointerException is. Do you know how to fix it?
Thanks

 

@BakedPotato_HD

No one will help you here because you do not know what you're doing.

 

@BakedPotato_HD
Ever tried using google? It works wonders...

 

I did google it but didn't really understand it
I actually got it to work by removing something and coding that part from the beginning

 

Check if current item is null.