Java Map implementation that returns a default value instead of null

Question

I have a Map<String, List<String>> in my code, where I'd avoid potential null pointers if the map's #get() method returned an empty list instead of null. Is there anything like this in the java API? Should I just extend HashMap?

Answer 1

Thanks to default methods, Java 8 now has this built in with Map::getOrDefault:

Map<Integer, String> map = ... map.put(1, "1"); System.out.println(map.getOrDefault(1, "2")); // "1" System.out.println(map.getOrDefault(2, "2")); // "2"