Asked there as well, not sure if the problem is actually gradle

spring plugin seems to be working fine

Was actually a spring problem, I was using an AbstractEntity with things like id, created updated etc

I have no idea why but implementing

equals

and

hashCode

in the abstract class worked

If you know why feel free to explain 😄

How to read queue's name for @RabbitListener from application.properties?

Hi springers

I am converting a Scala app to Spring Boot using Kotlin. I had a Scala object (which would have been a class of static methods in Java), to create a JWT, and to check the http-header for the jwt token and to read/verify the data...This all works well, but I am trying to access a property from

application.properties

, but this fails. I am using @Value("\${application.secret:}") lateinit var jwtSecret: String but this fails to initialise the secret from the application properties. I am not sure if I am missing another annotation to tell Spring to scan this particular kotlin file, but I couldnt find anything when searching.

@Value("\${application.secret:}")
   lateinit var jwtSecret: String

what is this in? class, object, top-level?

It is an Object

I think the issue is that by being an object, it is not being "created" by Spring

and I need to inject it into my Controller as a Service

I am converting it to a Class with a Service annotation now to see if that makes a difference

Yeah, that worked. Apologies for the dumb question!

@codemwnci You can declare a

@Bean

function inside a

@Configuration

class that returns the Object

With recent Spring versions, a lot of the methods in JdbcTemplate have become

@Nullable

. Thus I now get a ton of warnings for things that never expect null to be returned. Is there some commonly used alternative now?

Can the methods return null? Iirc, they properly annotated a lot of methods with the latest release.

Yes, they have made the methods properly annotated. However, many of those methods were never expected to return null, so there is a lot of code written to expect that.

So far, I can slap

!!

everywhere, or write my own

KdbcTemplate

which conforms to the usage.

But I wondered if this was common enough for others & some other recommended approach.

Sounds like bugs in your code if they're properly annotated IMHO...

No, the problem appears to be that when the Java code is unannotated, Kotlin does not warn about unsafe usages.

When it is annotated with

@Nullable

, then Kotlin expects that it can return null at any time.

The JdbcTemplate method is:

<T> T execute(String sql, PreparedStatementCallback<T> action) throws DataAccessException;

But in Kotlin, when your callback does not return null, then you do not have to account for it as a result of

execute

So, you can write a KdbcTemplate method such as:

fun <T> execute(sql: String, action: (PreparedStatement) -> T) : T {

Then your existing code will work great.

It’s not a bug in my code — execute() returns the value of the

action

callback..

FWIW, I have discovered that Spring 5 introduces a new

org.springframework.jdbc.core.JdbcOperationsExtensions

, written by Mario Arias which seems to try to solve some of this issue, but it is not fully adequate for me in handling nulls.

I think it is a valid issue that should be filed on Spring issue tracker.