Is there a better way to combine two string sets in java?

Question

I need to combine two string sets while filtering out redundant information, this is the solution I came up with, is there a better way that anyone can suggest? Perhaps som

Answer 1

You can do it using this one-liner

Set combined = Stream.concat(newStringSet.stream(), oldStringSet.stream())
        .collect(Collectors.toSet());

With a static import it looks even nicer

Set combined = concat(newStringSet.stream(), oldStringSet.stream())
        .collect(toSet());

Another way is to use flatMap method:

Set combined = Stream.of(newStringSet, oldStringSet).flatMap(Set::stream)
        .collect(toSet());

Also any collection could easily be combined with a single element

Set combined = concat(newStringSet.stream(), Stream.of(singleValue))
        .collect(toSet());