Chaining Optionals in Java 8

Question

Looking for a way to chain optionals so that the first one that is present is returned. If none are present Optional.empty() should be returned.

Assumi

Answer 1

You could do it like this:

Optional resultOpt = Optional.of(find1()
                                .orElseGet(() -> find2()
                                .orElseGet(() -> find3()
                                .orElseThrow(() -> new WhatEverException()))));

Though I'm not sure it improves readability IMO. Guava provides a way to chain Optionals:

import com.google.common.base.Optional;

Optional resultOpt = s.find1().or(s.find2()).or(s.find3());

It could be another alternative for your problem but does not use the standard Optional class in the JDK.

If you want to keep the standard API, you could write a simple utility method:

static  Optional or(Optional first, Optional second) {
    return first.isPresent() ? first : second;
}

and then:

Optional resultOpt = or(s.find1(), or(s.find2(), s.find3()));

If you have a lot of optionals to chains, maybe it's better to use the Stream approach as other mentionned already.