Using streams return null if value is false else return true

Question

I have the below code

 headers.stream().map(MyHeader::getIsCancelled).iterator(),

getIsCancelled returns boolean true/false.

I want to modify the above code to return null if the value is false, else return true. Should I use filter to filter for true value and automatically I will get true or null value?

Answer 1

By using filter , you can eliminate the false values instead of replacing them by null .

If you want to replace the false values by null , you should still use map :

headers.stream().map(h -> h.getIsCancelled() ? true : null).iterator()

I believe that should work, but if not, you can replace true with Boolean.TRUE .