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by this_user 2556 days ago
> Apparently he replaces null with null objects

That's what Optional was introduced for in Java 8. If you want to be absolutely null-safe, using it makes sense. But if you want to optimise performance, going with the slightly more risky route is still the better choice.
2 comments
kjeetgill 2556 days ago
That's not really "why" it was introduced. Optional is used as a null wrapper in other JVM languages so that idiom bled over pretty naturally.

Here's a talk "Optional - Mother of all Bikesheds" by Stuart Marks, the guy who added it to OpenJDK: https://m.youtube.com/watch?v=Ej0sss6cq14

It was mostly just meant to cover the zero or one case on fluent-style interfaces like the Streams API, so check as getFirst() or getAny(). In hindsight, the name Optional was a poor choice if they didn't want the idiom coming over.

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killface 2556 days ago
Passing optional objects as method params is bad. The trouble is that an Optional<T> can still be null itself.
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