I'm getting index out of bounds errors in my Bukkit plugin, and it's really beginning to piss me off...

I for the life of me can't figure this issue out!

Caused by: java.lang.IndexOutOfBoundsException: Index: 1, Size: 1

This is where I believe the code to be erroring...

for(int i = 0; i <= staffOnline.size(); i++) {
            if(i == staffOnline.size()) {
                staffList = staffList + staffOnline.get(i);
            } else {
                staffList = staffList + staffOnline.get(i) + ", ";
            }
        }