What would be the best approach for this Java null check? Should I use an Optional?

Question

I want to achieve the following:

LinkedHashMap<String, String> linkedHashMap = new LinkedHashMap<>();
linkedHashMap.put("someString", object.getObjectField().getValue());

If object.getObjectField() is null, then I get a NullPointerException. I can easily avoid it, with the following null check:

if(object.getObjectField() != null) {
    linkedHashMap.put("someString", object.getObjectField().getValue());
    } else {
    linkedHashMap.put("someString", "N/A");
}

However, I was thinking to find a better and prettier implementation, using Java 8 Optional, but in this case I still receive a NullPointerException:

linkedHashMap.put("someString", Optional.ofNullable(object.getObjectField().getValue()).orElse("N/A");

What would be the right approach in this case?

You *could* use the ternary operator: `linkedHashMap.put("someString", object.getObjectField() == null ? "N/A" : object.getObjectField().getValue());` — Lino, Feb 07 '22 at 13:02
[Related](https://stackoverflow.com/questions/56235254/optional-vs-if-else-if-performance-java-8/56235329#56235329) if not the dupe. [Another candidate](https://stackoverflow.com/questions/23454952/uses-for-optional/23464794#23464794). (didn't close because its my answer on the first one.) — Lino, Feb 07 '22 at 13:04

score 1 · Accepted Answer · answered Feb 07 '22 at 13:20

but in this case I still receive a NullPointerException

That's because you would still be invoking getValue() even if getObjectField() is null.

You can use Optional.map to apply a function if present:

Optional.ofNullable(object.getObjectField()).map(ObjectType::getValue)

If you want to use a default value, you can just add the orElse after that:

Optional.ofNullable(object.getObjectField()).map(ObjectType::getValue)
    .ofElse("N/A")

What would be the best approach for this Java null check? Should I use an Optional?

1 Answers1