Cleaning Kotlin method which returns the document name after the id

Question

I'm just getting to know the possibilities of Kotlin and mongoDB.
I am writing a method that returns the name of the street after the ID.
Everything works, but I find it quite sloppy.
Empty String initialization, returning more data from the collection than I would like. How do I straighten it? Could it be made into some expression body one-liner?

 fun getStreetNameByStreetId(id: String): String {
 val query = Query()
 query.fields().include("name")
 query.addCriteria(Criteria.where("_id").`is`(id))
 var streetName = ""
 mongoTemplate.executeQuery(
 query, STREET_COLLECTION
 ) { document: Document ->
 streetName = document.getValue("name").toString()
 }
 return streetName
}

• Tenfour04: I don't use mongo, but this doesn't look like it would even work. You modify streetName with an asynchronous callback, so you're returning the original empty String before the callback even has a chance to be called. e.g. stackoverflow.com/questions/57330766/…

Answer 1

This is how it would look in Java:

public String getStreetNameByStreetId(String id) {
 Query streetNameByStreetId = Query.query(
 Criteria.where("_id").is(id));
 byStreetId.fields().include("name");
 return mongoTemplate.find(streetNameByStreetId, Street.class)
 .get(0).getName();
}

I realize you are looking for how this would look in Kotlin, but it should look very similar. Also, for simple CRUD operations you might want to consider just using a MongoRepository and leveraging the Domain Specific Language (DSL).