Best way to check if a field of a field is null?

Question

Is there an elegant way to check if a string of fields is null?

Let's say I have:

String fieldD = myString.getFieldA().getFieldB().getFieldC().getFieldD();

I could do something like

String fieldD = null;
if (myString.getFieldA() != null
        && myString.getFieldA().getFieldB() != null
        && myString.getFieldA().getFieldB().getFieldC() != null) {
    String fieldD = myString.getFieldA().getFieldB().getFieldC().getFieldD();
}

or I could do something like

String fieldD = null;
try {
    String fieldD = myString.getFieldA().getFieldB().getFieldC().getFieldD();
} catch (NullPointerException e) {
    // do nothing
}

But there has to be a more elegant solution than either of these right? I'm sure this is already answered somewhere, but I can't seem to find it.

Welp, guess I'll go with the second option in my post and have catch clauses everywhere then. I was hoping for a simple one-liner since I currently have many fields which need to be checked back-to-back. Kind of gross to look at, but guess it can't be avoided :/ — Azianese, Jun 28 '21 at 19:53
Often the best solution is to write those methods so they cannot return null. Under no circumstances should anyone catch NullPointerException, as that class exists to expose programmer mistakes. — VGR, Jun 28 '21 at 19:54
That was one of the reasons they invented Optionals. Check the following article https://www.oracle.com/technical-resources/articles/java/java8-optional.html — Panagiotis Bougioukos, Jun 28 '21 at 19:57
Well, of course, one could use `Optional`: `Optional.ofNullable(myString).map(a -> a.getFieldA()).map(b -> b.getFieldB()).map(c -> c.getFieldC()).map(d -> d.getFieldD()).ifPresent(result -> ...)`. — MC Emperor, Jun 28 '21 at 19:58
Thanks for the suggestions and resources! I'll make sure to not go with the second option in my post and look into alternatives like Optionals — Azianese, Jun 28 '21 at 20:01

Best way to check if a field of a field is null?

0 Answers0