How to fix .UnsatisfiedDependencyException error in Spring? - spring-boot

Question

I have the following code:
package com.example.demo
import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication
import org.springframework.data.jpa.repository.Query
import org.springframework.data.repository.CrudRepository
import org.springframework.stereotype.Repository
import org.springframework.stereotype.Service
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.PostMapping
import org.springframework.web.bind.annotation.RequestBody
import org.springframework.web.bind.annotation.RestController
import javax.persistence.Entity
import javax.persistence.Id
import javax.persistence.Table
#SpringBootApplication
class DemoApplication
fun main(args: Array<String>) {
runApplication<DemoApplication>(*args)
}
#RestController
class MessageResource(var service: MessageService) {
#GetMapping
fun index(): List<Message> = service.findMessagesInDB()
#PostMapping
fun post(#RequestBody message: Message) {
service.addMessageToDB(message)
}
}
#Service
class MessageService(val db : MessageRepository) {
fun findMessagesInDB(): List<Message> = db.findMessages()
fun addMessageToDB(message: Message){
db.save(message)
}
}
#Repository
interface MessageRepository : CrudRepository<Message, String> {
#Query("select * from messages")
fun findMessages(): List<Message>
}
#Table(name ="MESSAGES")
#Entity
data class Message(#Id val id: String?, val text: String)
I get
java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List com.example.demo.MessageRepository.findMessages()!
I followed this kotlin-Spring tutorial: https://kotlinlang.org/docs/jvm-spring-boot-restful.html#add-database-support

Answer 1

It seems to me that a nativeQuery = true attribute is missing in your #Query. Try the following:
#Repository
interface MessageRepository : CrudRepository<Message, String> {
#Query(value = "select * from messages", nativeQuery = true)
fun findMessages(): List<Message>
}
Additionally, this custom #Query method seems unnecessary, since CrudRepository has a method (findAll()) that does exactly that.