Is there a way to tell Kotlin to convert all insta...

# announcements

[mathew murphy]

Is there a way to tell Kotlin to convert all instances of java.lang.String to String? rather than String! within a specified context, so that I get errors or warnings if I try to do (say) resultset.getString(2).trim()?

[groostav]

"within a specific context", I mean the type system might do it. would using an explicit type val resultSet: List<String?> = somejavaAPI.getResults()

solve your problem?

also, if the java API your getting your resultset back from is one you control, then kotlin will respect JSR 305 annotations, so you can download a copy of JSR 305 and use the `Nullable`/`Nonnull` annotations, and the calling kotlin code will stop using the platform type

[mathew murphy]

The API is JDBC, so I don't really control it. I guess eventually there will be a new version that has JSR 305 annotations...

[Alexey Belkov [JB]]

Kotlin 1.3.40 with its support of external annotations in IDEA might do what you want: https://blog.jetbrains.com/kotlin/2019/06/kotlin-1-3-40-released/. It's not mentioned in the blog post, but Intellij IDEA can infer such annotations automatically for Java libraries, for example the JDK. This will only work in the IDE though.