Java map.get(key) - automatically do put(key) and return if key doesn't exist?

Question

I am sick of the following pattern:

value = map.get(key);
if (value == null) {
    value = new Object();
    map.put(key, value);
}

This ex

Answer 1

Maybe I'm not seeing the whole problem, but how about using inheritance or composition to add this behavior to the Map object?