设置 r2dbcCustomConversions 时出现“Couldn't find PersistentEntity for type X”

Question

我在尝试设置 r2dbcCustomConversions 时收到 "Couldn't find PersistentEntity" 映射异常。

中的一些代码片段

这是我的代码：

@Configuration
class ServiceConfiguration : AbstractR2dbcConfiguration() {
    @Bean
    override fun connectionFactory() =
        ConnectionFactories.get("CONNECTION_STRING")

    override fun r2dbcCustomConversions() = R2dbcCustomConversions(
        storeConversions,
        listOf(PersonReadConverter(), PersonWriteConverter())
    )
}

@ReadingConverter
class PersonReadConverter : Converter<Row, Person> {
    override fun convert(source: Row): Person {
        return Person(
            source.get("id", String::class.java),
            source.get("name", String::class.java),
            source.get("age", Int::class.java)
        )
    }
}

@WritingConverter
class PersonWriteConverter : Converter<Person, OutboundRow> {
    override fun convert(source: Person): OutboundRow? {
        val row = OutboundRow()
        row["id"] = SettableValue.from(source.id!!)
        row["name"] = SettableValue.from(source.name!!)
        row["age"] = SettableValue.from(source.age!!)

        return row
    }
}

@Table
data class Person(@Id val id: String?, val name: String?, val age: Int?)

@Service
class PersonService(private val databaseClient: DatabaseClient) : InitializingBean {
    override fun afterPropertiesSet() {
        selectAll()
            .subscribe(
                { println("Data: $it") },
                { println("Error: $it") },
                { println("Done") }
            )
    }

    fun selectAll() = databaseClient
        .select()
        .from(Person::class.java)
        .fetch()
        .all()
}

这是我得到的输出：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'personService' defined in file [\demo\reactive-web\target\classes\com\example\demo\PersonService.class]: Invocation of init method failed; nested exception is org.springframework.data.mapping.MappingException: Couldn't find PersistentEntity for type class com.example.demo.Person!
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1783) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=11=](AbstractBeanFactory.java:320) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:868) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.2.0.M2.jar:5.2.0.M2]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.2.0.M2.jar:5.2.0.M2]
    at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:67) ~[spring-boot-2.2.0.M3.jar:2.2.0.M3]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:782) [spring-boot-2.2.0.M3.jar:2.2.0.M3]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:404) [spring-boot-2.2.0.M3.jar:2.2.0.M3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:319) [spring-boot-2.2.0.M3.jar:2.2.0.M3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1275) [spring-boot-2.2.0.M3.jar:2.2.0.M3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1263) [spring-boot-2.2.0.M3.jar:2.2.0.M3]
    at com.example.demo.DemoApplicationKt.main(DemoApplication.kt:13) [classes/:na]

我注意到文档有点过时了。例如，PersonWriteConverter 示例需要使用 SettableValue。我不确定这是一个错误还是我遗漏了什么

Answer 1

为域类型注册自定义转换器会将域类型视为简单类型。不检查简单类型的映射元数据。我们已经有一个 ticket to address that issue。

切换到 execute.sql("SELECT …").asType<Person>() 以使用结果。

设置 r2dbcCustomConversions 时出现“Couldn't find PersistentEntity for type X”

Getting “Couldn't find PersistentEntity for type X” when setting r2dbcCustomConversions

spring-data-r2dbc