In Java primitives aren’t objects, so you can’t use them in place of objects. However Java will automatically box/unbox primitives (aka autoboxing) into objects so you can do things like:
List<Integer> intList = new LinkedList<Integer>();
intList.add(1);
intList.add(new Integer(2));
...
Integer first = intList.get(0);
int second = intList.get(1);
But this is really just the compiler automatically converting types for you.