Java8: HashMap to HashMap using Stream / Map-Reduce / Collector
Map<String, String> x; Map<String, Integer> y = x.entrySet().stream() .collect(Collectors.toMap( e -> e.getKey(), e -> Integer.parseInt(e.getValue()) )); It’s not quite as nice as the list code. You can’t construct new Map.Entrys in a map() call so the work is mixed into the collect() call.