Splitting comma separated string values when streaming in java 8

Question

I have a String field called userId that has comma separated values like String user = "123","456" I want to split it. I have written something like this

List<String> idList= employeeList.stream()
    .map(UserDto::getUserId)
    .filter(Objects::nonNull)
    .map(String::toUpperCase)
    .distinct()
    .collect(Collectors.toList());

This UserDto::getUserId contains the comma separated values. Is it possible to split when streaming in the above logic.

Thanks

Answer 1

I think this should work

List<String> idList= employeeList.stream()
    .map(UserDto::getUserId)
    .filter(Objects::nonNull)
    .map(String::toUpperCase)
    .flatMap(s -> Arrays.stream(s.split(",")))//create a stream of split values
    .distinct()
    .collect(Collectors.toList());