Welcome to ShenZhenJia Knowledge Sharing Community for programmer and developer-Open, Learning and Share
menu search
person
Welcome To Ask or Share your Answers For Others

Categories

When using a Java Stream, sometimes null values can occur after mapping. Currently when these values need to be omitted, I use:

.stream()
.<other operations...>
.filter(element -> element != null)
.<other operations...>

For a more functional style a tiny helper method is quickly written:

public static <T> boolean nonNull(T entity) {
    return entity != null;
}

So that you can use a method reference instead:

.stream()
.<other operations...>
.filter(Elements::nonNull)
.<other operations...>

I could not find such a jdk method, even though I would suspect they have included one. Is there a different approach here? Or did they omit this for a reason?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
thumb_up_alt 0 like thumb_down_alt 0 dislike
91 views
Welcome To Ask or Share your Answers For Others

1 Answer

You can use Objects::nonNull from the Java8 SDK:

.stream()
.<other operations...>
.filter(Objects::nonNull)
.<other operations...>

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
thumb_up_alt 0 like thumb_down_alt 0 dislike
Welcome to ShenZhenJia Knowledge Sharing Community for programmer and developer-Open, Learning and Share
...