Java 8 Collectors.toMap SortedMap

Question

I\'m using Java 8 lambdas and want to use Collectors toMap to return a SortedMap. The best I can come up with is to call the following

Answer 1

Another way you can do this is to allow Collectors.toMap() to return whatever map it is going to return, and then pass that to a new TreeMap<>().

The caveat there is that this only works if your "hashCode()+equals()" and "compareTo" are consistent. If they aren't consistent, then you'll end up with the HashMap removing different set of keys than your TreeMap.