[FIXED] How to execute ApplicationRunner with Spring Boot (Kotlin)

Issue

This seems silly because it looks like such an easy thing but I am trying to initialize my spring boot project with dummy data using the ApplicationRunner. Can anyone explain why this code is not working? I am expecting it to print to the console the following:

Note(id=1, title=Note 1, text=null, user=user)
Note(id=2, title=Note 2, text=null, user=user)
Note(id=3, title=Note 3, text=null, user=user)

but instead it doesn't print anything at all.

Here is the implementation:

import com.bhanna.bugtracker.notes.Note
import com.bhanna.bugtracker.notes.NotesRepository
import org.springframework.boot.ApplicationArguments
import org.springframework.boot.ApplicationRunner
import org.springframework.stereotype.Component

@Component
class DataInitializer(val repository: NotesRepository) : ApplicationRunner {

    @Throws(Exception::class)
    override fun run(args: ApplicationArguments) {
        println("This should be printing to the console but it is not")

        listOf("Note 1", "Note 2", "Note 3").forEach {
            repository.save(Note(title = it, user = "user"))
        }
        repository.findAll().forEach { println(it) }
    }
}

Where Note is:

@Entity
data class Note(@Id @GeneratedValue var id: Long? = null,
                var title: String? = null,
                var text: String? = null,
                @JsonIgnore var user: String? = null) {
}

@Component
@RepositoryEventHandler(Note::class)
class AddUserToNote {

    @HandleBeforeCreate
    fun handleCreate(note: Note) {
        val username: String =  SecurityContextHolder.getContext().getAuthentication().name
        println("Creating note: $note with user: $username")
        note.user = username
    }
}

and NoteRepository is:

@RepositoryRestResource
interface NotesRepository : JpaRepository<Note, Long> {
    fun findAllByUser(name: String): List<Note>
}

and finally the main file:

@SpringBootApplication
class BugTrackerApplication

fun main(args: Array<String>) {
    runApplication<BugTrackerApplication>(*args)
}

I thought the @Component annotation meant spring will scan it and execute the underlying run() function since it is implementing ApplicationRunner. Can anyone explain whats going on here?

Solution

I tried your program and got this error message:

Configuration problem: @Configuration class 'BugTrackerApplication' may not be final. Remove the final modifier to continue.

So when I changed BugTrackerApplication to:

@SpringBootApplication
open class BugTrackerApplication

it worked as expected.

Answered By - FLUXparticle
Answer Checked By - Marie Seifert (JavaFixing Admin)