Ich versuche, den folgenden Code mit `stream in Lambda-Ausdrücke umzuwandeln, insbesondere in die verschachtelten foreach-Schleifen:

public static Result match (Response rsp) {
    Exception lastex = null;

    for (FirstNode firstNode : rsp.getFirstNodes()) {
        for (SndNode sndNode : firstNode.getSndNodes()) {
            try {
                if (sndNode.isValid())
                return parse(sndNode); //return the first match, retry if fails with ParseException
            } catch (ParseException e) {
                lastex = e;
            }
        }
    }

    //throw the exception if all elements failed
    if (lastex != null) {
        throw lastex;
    }

    return null;
}

Ich fange an mit:

rsp.getFirstNodes().forEach().?? // how to iterate the nested 2ndNodes?