Synchronized arrayList- incompatible types

Question

I'd like to create synchronized ArrayList in JAVA. I've used this code:

static ArrayList<User> listOfUsers = Collections.synchronizedList(new ArrayList<User>());

But NetBeans yells:

incompatible types:

required: ArrayList found: List

Any help possible?

Answer 1

Collections.synchronizedList() returns a List, not an ArrayList. Declare the user list as such:

static List<User> listOfUsers = Collections.synchronizedList(new ArrayList<User>());