Java 8 - Best way to transform a list: map or foreach?

Question

I have a list myListToParse where I want to filter the elements and apply a method on each element, and add the result in another list myFinalList.

Answer 1

If you use Eclipse Collections you can use the collectIf() method.

MutableList source =
    Lists.mutable.with(1, null, 2, null, 3, null, 4, null, 5);

MutableList result = source.collectIf(Objects::nonNull, String::valueOf);

Assert.assertEquals(Lists.immutable.with("1", "2", "3", "4", "5"), result);

It evaluates eagerly and should be a bit faster than using a Stream.

Note: I am a committer for Eclipse Collections.