How to iterate nested for loops referring to parent elements using Java 8 streams?

Question

I want to iterate nested lists using java8 streams, and extract some results of the lists on first match. Unfortunately I have to also get a values from the parent

Answer 1

It should be like this:

Edit: Thanks Holger for pointing out that the code won't stop at the first valid FirstNode

response.getFirstNodes().stream()
  .filter(it -> {it.getSndNodes().stream().filter(SndNode::isValid).findFirst(); return true;})
  .findFirst()
  .ifPresent(first -> first.getSndNodes().stream().filter(SndNode::isValid).findFirst().ifPresent(snd -> {
    result.setKey(first.getKey());
    result.setContent(snd.getContent());
  }));

A test can be found here