Polymorphic example with jsonb

OrderApp.kt

package com.example

import com.fasterxml.jackson.annotation.JsonProperty
import com.fasterxml.jackson.annotation.JsonTypeInfo
import com.vladmihalcea.hibernate.type.json.JsonBinaryType
import org.hibernate.annotations.Type
import org.hibernate.annotations.TypeDef
import org.springframework.boot.CommandLineRunner
import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.data.jpa.repository.JpaRepository
import java.io.Serializable
import java.util.*
import javax.persistence.*

@SpringBootApplication
class AuditExampleApplication

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

@Entity
@Table(name = "orders")
@TypeDef(name = "jsonb", typeClass = JsonBinaryType::class)
data class OrderEntity(

    val name: String,

    @Enumerated(EnumType.STRING)
    var currentStatus: Status,

    @Type(type = "jsonb")
    @Column(name= "product", columnDefinition = "jsonb")
    val product: Product
): Serializable {
    @Id
    val id: UUID = UUID.randomUUID()
}

@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS)
interface Product: Serializable

data class Book(@JsonProperty("author") val author: String) : Product
data class Pen(@JsonProperty("color") val color: String) : Product

enum class Status {
    STARTED, RECEIVED, SENT, DOWNLOADING, COMPLETED
}

interface OrderRepository : JpaRepository<OrderEntity, UUID>

@Configuration
class Config {

    @Bean
    fun init(orderRepository: OrderRepository) = CommandLineRunner {

        val order1 = OrderEntity("my first book", Status.STARTED, Book("my author"))
        val order2 = OrderEntity("my second book", Status.RECEIVED, Book("my author"))
        val pen1 = OrderEntity("my first pen", Status.COMPLETED, Pen("red"))
        val pen2 = OrderEntity("my second pen", Status.DOWNLOADING, Pen("red"))

        orderRepository.saveAll(listOf(order1, order2, pen1, pen2))
        orderRepository.findAll().forEach { println(it) }

        /**
         # Prints:
         
         OrderEntity(name=my first book, currentStatus=STARTED, product=Book(author=my author))
         OrderEntity(name=my second book, currentStatus=RECEIVED, product=Book(author=my author))
         OrderEntity(name=my first pen, currentStatus=COMPLETED, product=Pen(color=red))
         OrderEntity(name=my second pen, currentStatus=DOWNLOADING, product=Pen(color=red))
         */
    }

}

/**
# Database:

41a0567f-5cd3-4175-91b2-dfc44eac746e	COMPLETED	my first pen	{"color": "red", "@class": "com.example.Pen"}
43592556-c648-4b9a-a53f-3f17e45d6986	RECEIVED	my second book	{"@class": "com.example.Book", "author": "my author"}
965c050c-7dfa-4c7d-9a27-d5e5d05c99e9	DOWNLOADING	my second pen	{"color": "red", "@class": "com.example.Pen"}
9bb03be4-740e-4f5e-9115-5d39d2ff1b19	STARTED	        my first book	{"@class": "com.example.Book", "author": "my author"}
*/


// implementation("com.vladmihalcea:hibernate-types-52:2.10.3")

/**
# application.yml

spring:
  datasource:
    url: jdbc:postgresql://localhost:5432/example
    username: postgres
    password: postgres
  jpa:
    hibernate:
      ddl-auto: create

logging:
  level:
    org.hibernate.SQL: DEBUG
#    org.hibernate.type.descriptor.sql.BasicBinder: TRACE
*/