Use interfaces + JDK dynamic proxies instead of CGLIB

It allows to remove open keyword on repositories

src/main/kotlin/io/spring/messenger/Application.kt

@@ -12,6 +12,7 @@ import org.springframework.boot.CommandLineRunner
 import org.springframework.boot.SpringApplication
 import org.springframework.boot.autoconfigure.SpringBootApplication
 import org.springframework.context.annotation.Bean
+import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor
 import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder
 import org.springframework.transaction.annotation.EnableTransactionManagement
 import javax.sql.DataSource
@@ -30,6 +31,9 @@ open class Application {
     @Bean
     open fun transactionManager(dataSource: DataSource) = SpringTransactionManager(dataSource)
 
+    @Bean // PersistenceExceptionTranslationPostProcessor with proxyTargetClass=false, see https://github.com/spring-projects/spring-boot/issues/1844
+    open fun persistenceExceptionTranslationPostProcessor() = PersistenceExceptionTranslationPostProcessor()
+
     @Bean
     open fun init(ur: UserRepository, mr: MessageRepository) = CommandLineRunner {
         ur.createTable()

src/main/kotlin/io/spring/messenger/repository/CrudRepository.kt

@@ -0,0 +1,13 @@
+package io.spring.messenger.repository
+
+import org.postgis.PGbox2d
+import org.postgis.Point
+
+interface CrudRepository<T, K> {
+    fun createTable()
+    fun create(m: T): T
+    fun findAll(): Iterable<T>
+    fun deleteAll(): Int
+    fun findByBoundingBox(box: PGbox2d): Iterable<T>
+    fun updateLocation(userName:K, location: Point)
+}

src/main/kotlin/io/spring/messenger/repository/DefaultMessageRepository.kt

@@ -6,25 +6,33 @@ import io.spring.messenger.within
 import org.jetbrains.exposed.sql.*
 import org.jetbrains.exposed.sql.statements.UpdateBuilder
 import org.postgis.PGbox2d
+import org.postgis.Point
 import org.springframework.stereotype.Repository
 import org.springframework.transaction.annotation.Transactional
 
+interface MessageRepository: CrudRepository<Message, Int>
+
 @Repository
 @Transactional // Should be at @Service level in real applications
-open class MessageRepository() {
+class DefaultMessageRepository() : MessageRepository {
 
-    open fun createTable() = SchemaUtils.create(Messages)
+    override fun createTable() = SchemaUtils.create(Messages)
 
-    open fun create(m: Message): Message {
+    override  fun create(m: Message): Message {
         m.id = Messages.insert(toRow(m)).get(Messages.id)
         return m
     }
 
-    open fun findAll() = Messages.selectAll().map { fromRow(it) }
+    override fun findAll() = Messages.selectAll().map { fromRow(it) }
 
-    open fun findByBoundingBox(box: PGbox2d) = Messages.select { Messages.location within box }.map { fromRow(it) }
+    override fun findByBoundingBox(box: PGbox2d) = Messages.select { Messages.location within box }.map { fromRow(it) }
 
-    open fun deleteAll() = Messages.deleteAll()
+    override fun updateLocation(id:Int, location: Point) {
+        location.srid = 4326
+        Messages.update({ Messages.id eq id}) { it[Messages.location] = location}
+    }
+
+    override fun deleteAll() = Messages.deleteAll()
 
     fun toRow(m: Message): Messages.(UpdateBuilder<*>) -> Unit = {
         if (m.id != null) it[id] = m.id

src/main/kotlin/io/spring/messenger/repository/DefaultUserRepository.kt

@@ -10,24 +10,29 @@ import org.postgis.Point
 import org.springframework.stereotype.Repository
 import org.springframework.transaction.annotation.Transactional
 
+interface UserRepository: CrudRepository<User, String>
+
 @Repository
 @Transactional // Should be at @Service level in real applications
-open class UserRepository() {
+class DefaultUserRepository() : UserRepository {
 
-    open fun createTable() = SchemaUtils.create(Users)
+    override fun createTable() = SchemaUtils.create(Users)
 
-    open fun create(user: User) = Users.insert( toRow(user) )
+    override fun create(user: User): User {
+        Users.insert(toRow(user))
+        return user
+    }
 
-    open fun updateLocation(userName:String, location: Point) = {
+    override fun updateLocation(userName:String, location: Point) {
         location.srid = 4326
         Users.update({Users.userName eq userName}) { it[Users.location] = location}
     }
 
-    open fun findAll() = Users.selectAll().map { fromRow(it) }
+    override fun findAll() = Users.selectAll().map { fromRow(it) }
 
-    open fun findByBoundingBox(box: PGbox2d) = Users.select { Users.location within box }.map { fromRow(it) }
+    override fun findByBoundingBox(box: PGbox2d) = Users.select { Users.location within box }.map { fromRow(it) }
 
-    open fun deleteAll() = Users.deleteAll()
+    override fun deleteAll() = Users.deleteAll()
 
     fun toRow(u: User): Users.(UpdateBuilder<*>) -> Unit = {
         it[userName] = u.userName

src/main/kotlin/io/spring/messenger/web/UserController.kt

@@ -5,7 +5,6 @@ import io.spring.messenger.repository.UserRepository
 import org.postgis.PGbox2d
 import org.postgis.Point
 import org.springframework.http.HttpStatus.*
-import org.springframework.transaction.annotation.Transactional
 import org.springframework.web.bind.annotation.*
 
 @RestController