How to check if a scala Option type is None in Java code

Question

I have Scala class that will generate an Option[StructType] value which will be used in a Java function. In that java function, I need to check if this Option[StructType] is Scala None or not. How do I do that?

Scala class:

class Person(columns : String) {
    val recordStruct : Option[StructType] = {
        if ( columns != null && !columns.isEmpty()) {
          Some(new StructType(fields.map(field => 
                              StructField(field, StringType, true)).toArray))
        } else {
            None
        }
    }   
}

Java function:

StructType structure =  person.recordStruct().get();

// how to check if structure is None (in scala) ????

if (structure is None) {
    // ...
}

if(!structure.isDefined()) would tell you if structure is None. Except that structure isn't really an Option. person.recordStruct() is. — Dima
– Dima, Commented Mar 26, 2016 at 20:55
that's because structType isn't an Option (it's a StructType, duh). See my updated comment above. — Dima
– Dima, Commented Mar 26, 2016 at 20:58
You can just do StructType structure = person.recordStruct().orNull() if you prefer — Dima
– Dima, Commented Mar 26, 2016 at 21:02
so I should use person.recordStruct().isDefined(), not structure.isDefined() ? — jlp
– jlp, Commented Mar 26, 2016 at 21:02

Tzach Zohar · Accepted Answer · 2016-03-26 20:58:31Z

6

Option<StructType> maybeStructure = person.recordStruct();
if (maybeStructure.isEmpty()) { 
    // do something if None
} else {
    StructType structure =  person.recordStruct().get();
    // now you can use structure...
}

answered Mar 26, 2016 at 20:58

Tzach Zohar

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2 Comments

jlp Over a year ago

Thanks. By looking at them, it seems I can use either isDefined() or isEmpty() on Option type.

Tzach Zohar Over a year ago

Correct - of course o.isDefined() == !o.isEmpty().

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