Should I use Java8/Guava Optional for every method that may return null?

Question

Optional is used to represent nullable object, Some uses of this class include

1. As a method return type, as an alternative to returning null to
   indicate tha

Answer 1

Compared with Guava, one annoying problem with java.util.Optional is that it does not provide a method like

orElse(Optional): Optional

which is, on the other hand, defined in com.google.common.base.Optional as

or(Optional): Optional

The lack of this specific feature limits monadic applications of Java 8's Optional.

UPDATE:

Guava's or(Optional) can be replicated as in with Java 8 Optional as

optionalA.map(Optional::of).orElse(optionalB)

or

optionalA.map(Optional::of).orElseGet(() -> computeOptionalB)

UPDATE:

In Java 9 (finally!) you'll be able to use Optional.or(Supplier>):

optionalA.or(() -> computeOptionalB)

That's neat!