Stop PvP if a player is in an ArrayList

Hello! So my plugin uses a GUI menu to select a kit, after you select it you are put in an ArrayList,
How would I stop people in that ArrayList:

From using a command other than /leave;

And finally, stopping item drops when a player dies.

Can anyone help me?

 

1.

PHP:

//psuedocode
PlayerCommandPreprocessEvent():
    if the command name is not equals to /leave
    and the ArrayList contains the player name:
        cancel the event

2. http://jd.bukkit.org/rb/apidocs/org/bukkit/event/entity/EntityDeathEvent.html#getDrops()
3. Stop being lazy, and use Google to find your answer - your questions have already been asked (and answered).

 

Wizehh
I legitimately did use Google and the Forum but found nothing, or maybe I am just the worst searcher in history....

 

https://forums.bukkit.org/threads/disable-player-commands.157216/
https://forums.bukkit.org/threads/make-players-not-drop-certain-items-on-death.86428/

 

Wizehh
Then I am the worst searcher ever
I typed in the Search Bar:
Stop item drops

And I got one thing, something to do with Essentials

Then I go to Google,
Same thing;
Essentials.

 

Here's a tip: prefix all of your searches (when applicable) with site:forums.bukkit.org; that way, you'll only get Bukkit-related results. Example:
'site:forums.bukkit.org how to stop item drops'

 

I mostly google How to stop item drops bukkit and get a result from here or stackoverflow.

 

I believe it would be PlayerCommandPreprocessEvent. If the player is in the collection and the command is not "leave" cancel it.