Time between running commands to stop spam

I am at the moment creating a plugin that sends various commands to people, but it has the problem that it is easily spammable.
Is there a way to put a timer between running the command and then running it again?

 

One simple method is HashMap<String,Long> where you store their name and the current system time + cooldown. Check on that map onCommand and if the current system time is past their map entry, permit the command.

Use this to get the system time: System.currentTimeMillis()

You can't be more vague than that? If you're going to even mention it, at least give direction...

For this method to create a cooldown effect, you would first want an ArrayList<String> containing player names that you add when they use a command. When they send the command, start a delayed scheduled task to remove them from that arraylist. If they aren't on the arraylist then permit the command.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Thanks for the response, I still do not quite understand Hashmapping and Arraylists, but I will try to learn more about them.