Return null value for Java Streams

Question

Date finalexamDate = Person.stream()
    .map(PersonDetails::getexamDate)
    .max(Date::compareTo)
    .orElse(null);

The following code produces a

null pointer exception

as this person doesnt have any getexamdate during this case I wanted to return null to the finalexamDate

Tried adding Optional.ofNullable still produces the same error.

How should this be handled ? is there any way to handle along with the same line of code rather than checking one more if condition ?

Try adding `.filter(Objects::nonNull)` before your `max` line — Phil, May 28 '20 at 03:25

score 1 · Accepted Answer · answered May 28 '20 at 03:33

1

The max terminal method throws a Null pointer Exception if the maximum value is null . So it is safe to filter the values first so that the stream will only have non null values in it.

Date finalexamDate = Person.stream()
    .map(PersonDetails::getexamDate)
    .filter(Objects::nonNull)
    .max(Date::compareTo)
    .orElse("some default value");

answered May 28 '20 at 03:33

Ananthapadmanabhan

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Thanks for the clear explanation Ananth it worked – A K May 28 '20 at 03:45

Return null value for Java Streams

1 Answers1