I have this code and I got this exception from Cra...

# android

[Hadi Tok]

I have this code and I got this exception from Crashlytics Fatal Exception: java.lang.IllegalStateException: readValue(content, jacksonTypeRef<T>()) must not be null I couldn’t understand what is being null here. Any idea?

Untitled.kt

[ribesg]

This kind of message is ambiguous, but it actually says that a method readValue(content, jacksonTypeRef<T>()) (probably called by your call to mapper.readValue(string) returns null while not allowed to. Or at least that's what I think is happening.

[Hadi Tok]

himm let me check the jackson implementation.

[Hadi Tok]

so the field is PasswordToken? so it is clearly nullable. the type reference obtained through reified type reference. inline fun <reified T: Any> ObjectMapper.readValue(content: String): T = readValue(content, jacksonTypeRef<T>()) It should be return null. Anything I am missing here?

[ribesg]

If T: Any, then T is not nullable, T? is. If T: Any?, then T is nullable.

[ribesg]

For me something defined as fun <T: Any> foo(): T cannot return null

[Hadi Tok]

ok makes sense.

[Hadi Tok]

now I need to figure out how jackson can return null

[Hadi Tok]

I have run some tests the only way mapper.readValue(string) could return null is when string is null which doesn’t seem to be possible for me.

[Hadi Tok]

any ideas on this?

[ribesg]

Did you read the actual implementation of the method?

[Hadi Tok]

yes

[Hadi Tok]

So I figured this finally. “null” string was returned from the SharedPreferences and jackson is returning null in this case.

[Hadi Tok]

Gael thank you for your help

[ribesg]

👌