How to best create a Java 8 stream from a nullable object?

Question

What is the best/idiomatic way of doing a null check before getting a stream?

I have method that is receiving a List that might be null. So I can\'t jus

Answer 1

Personally I consider null deprecated and use Optional wherever possible despite the (tiny) performance overhead. So I use the interface from Stuart Marks with an implementation based on gdejohn, i.e.

@SuppressWarnings("unchecked")
static  Stream nullableCollectionToStream(Collection coll)
{
    return (Stream) Optional.ofNullable(coll)
                           .map(Collection::stream)
                           .orElseGet(Stream::empty);
}