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jbrains/FindPricePossiblyReturningNull.java

Created November 27, 2016 20:11
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I'm not convinced by this particular usage of Optional...
Raw
FindPricePossiblyReturningNull.java
public CommandResponse onBarcode(String barcode) {
Price price = catalog.findPrice(barcode);
return price == null
? new ProductNotFoundMessage(barcode)
: new ProductFoundMessage(price);
}
Raw
FindPriceReturningOptionalPrice.java
public CommandResponse onBarcode(String barcode) {
return catalog.findPrice(barcode)
.<CommandResponse> flatMap(price -> Optional.of(new ProductFoundMessage(price)))
.orElse(new ProductNotFoundMessage(barcode));
}
@mbjelac
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mbjelac commented Nov 28, 2016

If I didn't miss anything, it seems that catalog#findPrice returns Optional?
I prefer to not have Optional as a return type (nor as a parameter for that matter) for (at least) these reasons:

  • have to change or wrap existing APIs
  • the Optional instance can also be null (the Java language enables it ;)) so not really solving the problem

I prefer to use Optional.ofNullable.

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