在以下情况下如何避免 NPE？

Question

List<User> sortedList = userList.stream()       
    .sorted(Comparator.comparingInt(User::getAge).reversed())
    .collect(Collectors.toList());

sortedList.forEach(System.out::println)

In the above case if User is null it is giving NPE. How to avoid NPE here?

Answer 1

Yes I got the solution. It is very easy. Just use stream. filter(a->a!=null)...

List<User> sortedList = userList.stream()
    .filter(a->a!=null)       
    .sorted(Comparator.comparingInt(User::getAge).reversed())
    .collect(Collectors.toList());

sortedList.forEach(System.out::println)