Optional<T> does not handle null elements

Question

As I experimented Optional<T> does not handle null elements, so in the following example it throws a NullPointerException in the last statement:

List<String> data = Arrays.asList("Foo", null, "Bar");
data.stream().findFirst().ifPresent(System.out::println);
data.stream().skip(1).findFirst().ifPresent(System.out::println);

So, I still have to explicitly deal with null and filter non-null elements, such as:

data.stream()
    .filter(item -> item != null)
    .skip(1)
    .findFirst()
    .ifPresent(System.out::println);

Is there any alternative that avoids dealing explicitly with null as: item != null

Answer 1

You can use .filter(Objects::nonNull) using the method Objects.nonNull(…) added for this purpose.

There is no way to avoid explicit filtering, unless you avoid having nulls in your source list in the first place.

Note that it would be strange if the Optional handled the null in this case as it would yield an empty optional which had the semantic of “there is no first element” which implies “the stream was empty” which is just wrong.

Dealing with nulls explicitly is the cleanest solution here as it also allows you to explicitly tell whether you want .filter(Objects::nonNull).skip(1), .skip(1).filter(Objects::nonNull)…

…or .map(s->s==null? "null-replacement": s).findFirst()