Guava Optional type, when transformation returns another Optional

Question

I have a method that procudes an Optional

But this String must be parsed at another application level as Integer or Long.

This I h

Answer 1

Another options except those stated above:

• use plain old if/else (Guava team recommends not to overuse such constructs, it's often wise to obey these recommendation - otherwise you won't spare much lines of code and make readability worse)
• use dirty trick: from(singleton("Toto")).transform(STRING_TO_INTEGER_FUNCTION).filter(notNull()).first().orNull() - only hypothetical idea, IMHO its badly readable too. At least it contains none generics, ?: operator or anonymous class, at the cost of more static imports.
• wait for Java 8, where Optional.map allows null transformation result

You can vote for http://code.google.com/p/guava-libraries/issues/detail?id=1171 . Unfortunately Guava team seems hesitant with shifting this issue to some result.