How to replace "return optObj.isPresent() ? new Obj2(optObj) : null" in a functional style?

DIBits :

My IDE (InteliJ) keeps pointing me that my code "Can be replaced with single expression in functional style", highlighting the isPresent():

return timestamp.isPresent() ? new Obj2(timestamp.get()) : null;

timestamp is initialised like an Optional:

Optional<Date> timestamp = ...

My assumption is that I should use ifPresent. like this timestamp.ifPresent(Obj2::new). But ifPresent is void and I have no opportunity to return the created Object. Also cant then return null. Is there a solution to my code?

Ousmane D. :

You're correct in saying ifPresent returns void and hence not suitable in this case. Your IDE is suggesting that you can simply do:

timestamp.map(Obj2::new).orElse(null);

This reads as "if the Optional timestamp has a present state then pass the object it contains into the Obj2 constructor and returns this new Obj2 instance otherwise (orElse) return null.

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on another note, IntelliJ IDEA can help you generate the code it's suggesting.

for example, given the below screenshot:

I simply clicked on the "highlighted" part and pressed "ALT + ENTER", and IntelliJ suggests whether it should replace the condition with a functional style.