Skip to content

Instantly share code, notes, and snippets.

@matchilling matchilling/README.md
Last active May 3, 2020

Embed
What would you like to do?
Setting autogenerated Id manually in Hibernate

Setting auto-generated Ids manually with Hibernate

In this tutorial, you will learn how to implement a custom IdentifierGenerator to support auto-generated and manually assigned Ids using Hibernate.

Continue reading ...

package com.matchilling.lib.hibernate
import org.hibernate.engine.spi.SharedSessionContractImplementor
import org.hibernate.id.IdentifierGenerator
import java.io.Serializable
import java.util.*
import kotlin.reflect.full.declaredMemberProperties
import kotlin.reflect.jvm.javaType
class UuidGenerator : IdentifierGenerator {
override fun generate(
session: SharedSessionContractImplementor?,
instance: Any?
): Serializable {
val id = instance!!::class.declaredMemberProperties.find {
it.name == "id" && it.returnType.javaType.typeName == UUID::class.java.canonicalName
}?.getter?.call(instance)
return if (id != null) {
id as UUID
} else {
UUID.randomUUID()
}
}
companion object {
const val NAME = "uuid"
const val STRATEGY = "com.matchilling.lib.hibernate.UuidGenerator"
}
}
package com.matchilling.lib.hibernate
import io.mockk.mockk
import org.hibernate.engine.spi.SharedSessionContractImplementor
import org.junit.Test
import org.junit.jupiter.api.Assertions.assertEquals
import java.util.*
internal class UuidGeneratorTest {
private val subject = UuidGenerator()
private val uuid = Regex("[0-9a-fA-F]{8}(?:-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12}")
internal class EntityImpl(val id: UUID?)
@Test
fun `should assign a random UUID if id prop is null`() {
// given
val instance = EntityImpl(id = null)
// and
val session = mockk<SharedSessionContractImplementor>()
// when
val id = subject.generate(session, instance)
// then
assert(id.toString().matches(uuid))
}
@Test
fun `should not generate a new UUID when id prop is not null`() {
// given
val expected = UUID.fromString("d1f1ece1-c84b-465f-9529-0c3820c0c2d7")
// and
val instance = EntityImpl(id = expected)
// and
val session = mockk<SharedSessionContractImplementor>()
// when
val actual = subject.generate(session, instance)
// then
assertEquals(expected, actual)
}
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.