I'm trying to use Spring Data JDBC with Kotlin data-classes, and after adding #Transient property to primary constructor I received error on simple findById call:
java.lang.IllegalStateException: Required property transient not found for class mitasov.test_spring_data_with_kotlin.Entity!
my entity class looks like below:
data class Entity(
#Id
var id: String,
var entityName: String,
#Transient
var transient: List<TransientEntity>? = mutableListOf(),
)
After reading that issue I've tried to make #PersistenseConstructor without #Transient field:
data class Entity(
#Id
var id: String,
var entityName: String,
#Transient
var transient: List<TransientEntity>? = mutableListOf(),
) {
#PersistenceConstructor
constructor(
id: String,
entityName: String,
) : this(id, entityName, mutableListOf())
}
But this didn't help me and I'm still getting that error.
How can I solve this problem?
It's turned out that my second attempt IS the solution.
The trick was in my Run/Debug configuration for tests.
In IDEA Preferences I have checked Preferences | Build, Execution, Deployment | Build Tools | Maven | Runner — Delegate IDE build/run actions to Maven checkbox, and this means that I need to manually recompile my project before running tests.
Solution
So, this is it, the solution for error
java.lang.IllegalStateException: Required property transient not found for class mitasov.test_spring_data_with_kotlin.Entity!
is making #PersistenseConstructor without #Transient fields:
data class Entity(
#Id
var id: String,
var entityName: String,
#Transient
var transient: List<TransientEntity>? = mutableListOf(),
) {
#PersistenceConstructor
constructor(
id: String,
entityName: String,
) : this(id, entityName, mutableListOf())
}
Related
I'm trying to create a somewhat generic implementation using kotlin and neo4j. My idea right now is that I want to have a GeoNode that can point to any kind of GeoJson feature (e.g. "Feature" or "FeatureCollection")
I tried to do this using kotlins sealed classes, e.g.
#JsonTypeInfo(
use = JsonTypeInfo.Id.NAME,
include = JsonTypeInfo.As.PROPERTY,
property = "type"
)
#JsonSubTypes(
JsonSubTypes.Type(value = GeoJsonFeature::class, name = "GeoJsonFeature")
)
#Node
sealed class FeatureContract(
#GeneratedValue #Id var id: Long? = null,
#Version var version: Long? = null
) {
companion object {
#JsonCreator
#JvmStatic
private fun creator(name: String): FeatureContract? {
return FeatureContract::class.sealedSubclasses.firstOrNull {
it.simpleName == name
}?.objectInstance
}
}
}
data class GeoJsonFeature(
val geometry: GeometryContract,
) : FeatureContract()
data class GeoJsonFeatureCollection(
val features: List<GeoJsonFeature>,
) : FeatureContract()
// and the "GeoNode" that holds this
#Node
data class GeoNode(
#Id val id: String,
#Version var version: Long? = null
#Relationship(type = "feature") var feature: FeatureContract?, // Should be either a featureCollection or a feature,
)
The idea is that I can have a point on a map that points to any kind of GeoJson.
It seems I am successful in serializing this and getting it into the Neo4J-db on write, however, on reading I get
Failed to instantiate [FeatureContract]: Is it an abstract class?; nested exception is java.lang.InstantiationException
The Jackson annotations are there cause I hoped they would help me (that Neo4J-OGM was using it under the hood) but it doesn't seem to have done the trick. I've read about Neo4JEntityConverters but I haven't understood how one can to this for a full object like this. Is there any good way to use sealed classes in kotlin with the neo4j-OGM for both serialization and deserialization?
Using spring boot 2.4.4 and spring-boot-starter-data-neo4j
I'm writing a very simple Spring Data JDBC repository in Kotlin (using Postgres as the database):
data class Label(
#Id
#GeneratedValue
#Column( columnDefinition = "uuid", updatable = false )
val id: UUID,
val name: String
)
#Repository
interface LabelRepository: CrudRepository<Label, UUID> {}
When I do repository save:
val l = Label(id = UUID.randomUUID(), name = "name")
labelRepo.save(l)
It works fine. But since id is not null Spring Data JDBC will always treat it as an "update" to an existing label entity instead of creating a new one with generated ID.
So I changed id: UUID to id: UUID? And having val l = Label(id = null, name = "name")
But call the same save() method gives me:
java.lang.NoSuchMethodError: 'org.springframework.data.relational.core.dialect.IdGeneration org.springframework.data.relational.core.dialect.Dialect.getIdGeneration()'
I have tried a solution here: https://jivimberg.io/blog/2018/11/05/using-uuid-on-spring-data-jpa-entities/
But it didn't work, still gives me the same error
Wondering what's the cause of this and why this error pops up only when I change UUID to UUID??
nvm, turns out I have to use the implementation("org.springframework.boot:spring-boot-starter-data-jdbc") dependency instead of implementation("org.springframework.data:spring-boot-starter-data-jdbc:2.1.3")
I have a Kotlin data class node for Neo4j nodes:
#NodeEntity
data class MyNode (
#Id #GeneratedValue var dbId: Long? = null,
#Index(unique = true) val name: String,
val description: String
)
and a Spring repository:
interface MyNodesRepository : Neo4jRepository<MyNode, Long>
Then, when I save a node into the DB via this repository it is empty, without any properties:
val node = MyNode(null, "name 1", "lorem ipsum")
myNodesRepository.save(node)
after the save(node) call, the node.dbId is set to the Neo4j's internal id i.e. it is null before save() and has a value afterwards. I can also see the node in the Neo4j browser, but it does not have name and description properties.
After that, when I try to load all nodes the call crashes with InvalidDataAccessApiUsageException because it cannot deserialize/map the nodes with null/missing name and description:
val allNodes = myNodesRepository.findAll()
If I add a custom save method to my repository, where I manually create the node with CQL query, then everything works.
interface MyNodesRepository : Neo4jRepository<MyNode, Long> {
#Query(
"MERGE (mn:MyNode {name:{name}})\n" +
"ON CREATE SET m += {description:{description}}"
)
fun customSave(#Param("name") name: String, #Param("description") description: String)
}
Now the findAll() loads my newly created and/or updated nodes.
I am using org.springframework.boot:spring-boot-starter-data-neo4j:2.1.6.RELEASE and this is inside a Spring Boot CLI application so no web server and RestControllers.
What am I doing wrong?
EDIT: This is now solved in Neo4j OGM 3.1.13
EDIT: This is now solved in Neo4j OGM 3.1.13 and the workaround below is not needed anymore.
ORIGINAL ANSWER
After few days of debugging it looks like there is a bug in Neo4j OGM for Kotlin data classes where it does not save val properties -- both in data classes and normal classes. So change from val properties:
#NodeEntity
data class MyNode (
#Id #GeneratedValue var dbId: Long? = null,
#Index(unique = true) val name: String,
val description: String
)
to all var properties:
#NodeEntity
data class MyNode (
#Id #GeneratedValue var dbId: Long? = null,
#Index(unique = true) var name: String,
var description: String
)
works. Now both saving and loading works, but it is not idiomatic Kotlin.
So at least we have a workaround.
I can't understand, what's wrong with my Service. I receive org.hibernate.StaleObjectStateException trying to run this method:
fun updateNameForPhone(phone: String, name: String): Client {
val res = clientRepository.findByPhone(phone) ?: throw ClientNotFoundException(phone)
res.name = name
return clientRepository.save(res)
}
ClientRepository:
#Repository
interface ClientRepository : JpaRepository<Client, UUID> {
fun findByPhone(phone: String): Client?
}
Client entity:
#Entity
data class Client(
var name: String = "",
var phone: String = "",
#Id #GeneratedValue(strategy = GenerationType.AUTO)
val uuid: UUID = defaultUuid()
)
Exception:
Object of class [com.app.modules.client.domain.Client] with identifier
[12647903-7773-4f07-87a8-e9f86e99aab3]: optimistic locking failed;
nested exception is org.hibernate.StaleObjectStateException: Row was
updated or deleted by another transaction (or unsaved-value mapping
was incorrect) :
[com.app.modules.client.domain.Client#12647903-7773-4f07-87a8-e9f86e99aab3]"
What is the reason?
I'm using Kotlin 1.3.11, Spring Boot 2.1.1, MySql. I don't run it in different threads, just trying with single request.
Well, finally I've found a solution. Better say workaround.
The problem is in the way spring uses UUID as entity identifier.
So there are two workarounds, solving this issue:
first, you can change your id field type to other one, such as Long, for example, if it's possible to you;
or you can add this annotation to your uuid field: #Column(columnDefinition = "BINARY(16)").
The last solution I've found from this question.
I currently am working on a project that uses Spring Boot, written in Kotlin. It has got to be mentioned that I am still relatively new to Kotlin, coming from Java. I have a small database consisting of a single table that is used to look up files. In this database, I store the path of the file (that for this testing purpose is simply stored in the the resources of the project).
The object in question looks as follows:
#Entity
#Table(name = "NOTE_FILE")
class NoteFile {
#Id
#GeneratedValue
#Column(name = "id")
var id: Int
#Column(name = "note")
#Enumerated(EnumType.STRING)
var note: Note
#Column(name = "instrument")
var instrument: String
#Column(name = "file_name")
var fileName: String
set(fileName) {
field = fileName
try {
file = ClassPathResource(fileName).file
} catch (ignored: Exception) {
}
}
#Transient
var file: File? = null
private set
constructor(id: Int, instrument: String, note: Note, fileName: String) {
this.id = id
this.instrument = instrument
this.note = note
this.fileName = fileName
}
}
I have created the following repository for retrieving this object from the database:
#Repository
interface NoteFileRepository : CrudRepository<NoteFile, Int>
And the following service:
#Service
class NoteFileService #Autowired constructor(private val noteFileRepository: NoteFileRepository) {
fun getNoteFile(id: Int): NoteFile? {
return noteFileRepository.findById(id).orElse(null)
}
}
The problem that I have is when I call the getNoteFile function, neither the constructor nor the setter of the constructed NoteFile object are called. As a result of this, the file field stays null, whereas I expect it to contain a value. A workaround this problem is to set the fileName field with the value of that field, but this looks weird and is bound to cause problems:
val noteFile: NoteFile? = noteFileService.getNoteFile(id)
noteFile.fileName = noteFile.fileName
This way, the setter is called and the file field gets the correct value. But this is not the way to go, as mentioned above. The cause here could be that with the Spring Data framework, a default constructor is necessary. I am using the necessary Maven plugins described here to get Kotlin and JPA to work together to begin with.
Is there some way that the constructor and/or the setter does get called when the object is constructed by the Spring (Data) / JPA framework? Or maybe should I explicitly call the setter of fileName in the service that retrieves the object? Or is the best course of action here to remove the file field as a whole and simply turn it into a function that fetches the file and returns it like that?