Java Optional missing feature

(Un)boxing!

What if we lived in world where it’s possible to compile such code:

class Unboxing {
    public static void myIntegerAcceptingMethog(Integer value) {
    }

    public static void main(String[] args) {
        Optional<Integer> value = Optional.of(1);
        
        // look man! Optional<Integer> automatically converted to Integer:
        myIntegerAcceptingMethog(value); 
    }
    
}

Why do I need this possibility you would ask? For simplicity. Currently, the best we can do in such case is:

Optional<Integer> optionalValue = Optional.of(1);
Integer value = optionalValue.get();
myIntegerAcceptingMethog(value);

Optional<Integer> optionalValue = Optional.of(1);
optionalValue.ifPresent(value -> myIntegerAcceptingMethog(value));

There is significant inconvenience in these lines: I have to name the same thing twice and this leads to artificial and absurd names (like optionalValue). This is visible especially well when working with Spring Data repositories:

void doSmthWithOrder(Order) {
}

void evenMoreOrderProcessing(Order) {
}

void processOrder(Long id) {
    Optional<Order> a = orderRepository.findById(id);
    if (a.isPresent()) {
        b = a.get();
        doSmthWithOrder(b);
        evenMoreOrderProcessing(b);
    } else {
        throw new NotFoundException();
    }
}

Now my question is: what are good names instead of a and b? And why do I have to name it twice? In my dream world I could write:

void doSmthWithOrder(Order) {
}

void evenMoreOrderProcessing(Order) {
}

void processOrder(Long id) {
    Optional<Order> order = orderRepository.findById(id);
    if (order.isPresent()) {
        doSmthWithOrder(order);
        evenMoreOrderProcessing(order);
    } else {
        throw new NotFoundException();
    }
}

All it requires from Java is the ability to convert from Optional<E> to E under the hood. If only had mechanism which takes one physical representation of object and coverts it to the different one keeping logical value intact! Oh wait! We do ;)

PS. TIL that JLS defines conversions. I should probably rename this post title as my imaginary feature isn’t really (un)boxing, but this way it’s more clickbait-y ;)

Written on September 22, 2023