Making it so a player can't hurt certain players

Hi, so I want to create a small CTF/CTW bukkit plugin for a friend's server and I was wondering how to make it so people from one team can only hurt people from the other team. Thanks for the help in advance

 

Well how do you store each team?
If your using an arraylist say for team 1 and team 2, you can get the entity and if the entity matches the damager, event.setCancelled(true);

 

Try doing something like this:
Make an arraylist which stores players of each team
Then do EntityDamageByEntity event and check the arraylist.

Code:

if(hs.containsKey(e.getEntity())){    //if the hashmap contains the entity you are about to hit
            e.setCancelled(true);    //set cancelled
     
        } else {
            e.setCancelled(false);    //if it doesn't,hit the player 

EDIT: slater pretty much covered it....darn didn't see his post

 

Oh, okay. My main problem was I couldn't find the right event for it. Thanks.