ServerSideCat ServerSideCat - 7 months ago 26
Java Question

Java 8 Stream String Null Or Empty Filter

I've got Google Guava inside Stream:

this.map.entrySet().stream()
.filter(entity -> !Strings.isNullOrEmpty(entity.getValue()))
.map(obj -> String.format("%s=%s", obj.getKey(), obj.getValue()))
.collect(Collectors.joining(","))


As you see there is a statement
!String.isNullOrEmpty(entity)
inside the filter function.

I don't want to use Guava anymore in the project, so I just want to replace it simply by:

string == null || string.length() == 0;


How can I do it more elegant?

fge fge
Answer

You can write your own predicate:

final Predicate<Map.Entry<?, String>> valueNotNullOrEmpty
    = e -> e.getValue() != null && !e.getValue().isEmpty();

Then just use valueNotNullOrEmpty as your filter argument.