Question

我对Java和Spring还是很陌生，这是我的第一个Kotlin应用程序，因此我的问题可能是第8层（我）。但是我真的不知道我做错了什么。根据本教程（https://www.baeldung.com/kotlin-mongodb-spring-webflux），此方法应该有效。

我的常规应用设置是Controller-> Service-> Repository（我没有添加控制器，因为这不是问题）。我的问题是工厂无法创建存储库Bean。

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'driveController' defined in file [/Users/sburger/Documents/Dev/Gravity/App Framework/bouncr/build/classes/kotlin/main/de/example/drive/controller/DriveController.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'driveService' defined in file [/Users/sburger/Documents/Dev/Gravity/App Framework/bouncr/build/classes/kotlin/main/de/example/drive/service/DriveService.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'IBookingsRepository': Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: kotlin/reflect/full/KClasses
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:769) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:218) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1325) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1171) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:849) ~[spring-beans-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.5.RELEASE.jar:5.1.5.RELEASE]
    at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:67) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) ~[spring-boot-2.1.3.RELEASE.jar:2.1.3.RELEASE]
    at de.example.AppKt.main(App.kt:14) ~[main/:na]
    at de.example.AppKt.main(App.kt) ~[main/:na]

App.kt

@SpringBootApplication(exclude = [MongoReactiveDataAutoConfiguration::class])
open class App

fun main() {
    runApplication<App>()
}

MongoConfig.kt

@Configuration
@EnableReactiveMongoRepositories(basePackageClasses = [IBookingsRepository::class])
open class MongoConfig : AbstractReactiveMongoConfiguration() {
    override fun getDatabaseName() = "exampledb"

    override fun reactiveMongoClient() = mongoClient()

    @Bean
    override fun reactiveMongoTemplate() = ReactiveMongoTemplate(mongoClient(), databaseName)

    @Bean
    open fun mongoClient(): MongoClient = MongoClients.create()

}

我不得不将课程和娱乐标记为“开放”。没有它，构建将无法正常工作。这已经与本教程有所不同。

DriveService.kt

interface IDriveService {
    fun getBookings(userId: String) : Flux<Booking>
}

@Service
class DriveService @Autowired constructor(private val bookingsRepository: IBookingsRepository) :
    IBookingService {
    override fun getBookings(userId: String): Flux<Booking> {
       return bookingsRepository.findAll()
    }
}

“ findAll（）”方法是从ReactiveMongoRepository继承的

BookingsRepository.kt

interface IBookingsRepository : ReactiveMongoRepository<Booking, String>

该接口显然没有init函数，但在本教程中也没有。所以我认为它应该按原样工作？

有人暗示此设置有什么问题吗？

Answer 1

这里有几个问题：

您需要向org.jetbrains.kotlin:kotlin-reflect添加依赖项。如果您在https://start.spring.io/生成Kotlin项目，则应将其自动添加。
Baeldung教程不好。他们排除了自动配置没有理由，或者至少没有解释原因。 Spring Boot就是关于 Convention Over Configuration，因此默认应使用尽可能多的自动配置。
正如您在注释中指出的那样，不排除自动配置会导致异常。这是由于Spring Data MongoDb中的一个错误，该错误是由于DATAMONGO-2355而最近打开了票证this question的。
在这种情况下，正确的解决方案不是排除自动配置，而是更多地使用它。这里没有理由扩展AbstractReactiveMongoConfiguration。如this answer中所述，您可以通过属性配置数据库名称，并保留所有其他属性的自动配置。如果由于某种原因需要扩展AbstractReactiveMongoConfiguration，则在修复该错误之前，您可以覆盖reactiveMongoTemplate()方法，以将返回类型缩小为ReactiveMongoTemplate，如this answer中所述。 / p>

未生成Spring ReactiveMongoRepository bean

1 个答案: