How to return if optional is present and continue if not

Question

I have a optional method which returns Cat object (which is a optional). From the place I call It i would like to handle it in a way if cat is present then return otherwise continue

Opitional<Cat> option = isCatFound();
if (option.isPresent()) {
return option.get();
}
//DO STUFF HERE IF NO CAT FOUND

The above code is what I have now. I like to use something better than that, a single line solution.

Is there such possibility ? or correct way to use Optional ?

Answer 1

The Optional class provides a method for exactly that purpose: orElseGet(Supplier). So, with some little helper method you can do this:

Optional<Cat> option = isCatFound();
return option.orElseGet(this::noCatFound);

private Cat noCatFound() {
    // do whatever is appropriate here
    return null;
}

Of course, you could move the helper method's body into a lambda exprssion that feeds the orElseGet method.

Answer 2

Since your method has to return a value of that type at the end, you could use

Optional<Cat> option = isCatFound();
return option.orElseGet(() -> {
  // DO STUFF HERE IF NO CAT FOUND
  // WHICH WILL EVENTUALLY RETURN A VALUE
};

If your “stuff if no cat found” fits into a single line, it might be an option. Otherwise I don’t see any advantage over your original code. Especially as it has the disadvantage that the alternative code path can’t throw checked exceptions any more.