Use Streams to return Boolean if all the List values in a Map are empty/not-empty

Question

Given a Map mapping a String to a List, is there a way to use Java Streams to return a Boolean where TRUE means one or more list had elements? If all lists in the map were e

Answer 1

int size = Map.entrySet().stream()
                           .map(entry -> entry.getValue())
                           .flatMap(list -> list.stream())
                           .size();
if(size==0)
  return Boolean.False;
else
  return Boolean.True;

This code is a simple one this may help for your work .