DAO与多个数据库一起在Spring中无法与Kotlin一起使用

问题描述

我正在和Kotlin学习Spring（启动）。 我设法通过JPA信息库建立了一个可运行的Spring应用程序。

interface APixRepo : org.springframework.data.repository.Repository<APix,EroPixKulcs>
{
  @Query( value="select * from felhaszn",nativeQuery = true
        )
  fun sokasag(): Iterable<APix>
}

@RestController
@RequestMapping("/apix")
class AKontroller(private val dao: APixRepo)
{
  @GetMapping("/sokasag")
  fun sokasag() = dao.sokasag()
}

其中APix是我的实体类。还有另外两个相似的实体以及仓库和控制器。
（本机SQL对我很重要，这是我最多的专家。）
而且由于这三个实体位于三个不同的数据库中，所以我不得不使用描述为here的XxxDataSourceConfiguration魔术（Xxx = APix和另外两个）。
而且仍然有效。

现在我意识到，回购方法对我不利，因为我的SQL必须是动态的，并且您只能在@Query（answer）中编写常量SQL。 所以我根据this question and answer将我的仓库改成了DAO：

interface APixDAO
{
  fun sokasag(): Iterable<APix>
}

class APixRepoImpl constructor(@PersistenceContext var em: EntityManager)
{
  fun sokasag(): Iterable<APix>
  {
    return em.createNativeQuery("select * from felhaszn").getResultList() as Iterable<APix>
  }
}

interface APixRepo : org.springframework.data.repository.Repository<APix,EroPixKulcs>,APixDAO {}

现在问题开始了。在这种状态下（没有任何其他注释），错误是这样的：

***************************
APPLICATION FAILED TO START
***************************

Description:

Parameter 0 of constructor in com.zz.sokdb.apix.APixRepoImpl required a single bean,but 3 were found:
        - org.springframework.orm.jpa.SharedEntityManagerCreator#0: defined by method 'createSharedEntityManager' in null
        - org.springframework.orm.jpa.SharedEntityManagerCreator#1: defined by method 'createSharedEntityManager' in null
        - org.springframework.orm.jpa.SharedEntityManagerCreator#2: defined by method 'createSharedEntityManager' in null


Action:

Consider marking one of the beans as @Primary,updating the consumer to accept multiple beans,or using @Qualifier to identify the bean that should be consumed

和

ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'AKontroller' defined in file [/home/laca/spring/kotlin/zz/sokdb/build/classes/kotlin/main/com/zz/sokdb/AKontroller.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'APixRepoImpl' defined in file [/home/laca/spring/kotlin/zz/sokdb/build/classes/kotlin/main/com/zz/sokdb/apix/APixRepoImpl.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'javax.persistence.EntityManager' available: expected single matching bean but found 3: org.springframework.orm.jpa.SharedEntityManagerCreator#0,org.springframework.orm.jpa.SharedEntityManagerCreator#1,org.springframework.orm.jpa.SharedEntityManagerCreator#2

我尝试过：

class AKontroller(@org.springframework.beans.factory.annotation.Qualifier("apixEntityManager") private val dao: APixRepo)

现在出现错误：

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'AKontroller' defined in file [/home/laca/spring/kotlin/zz/sokdb/build/classes/kotlin/main/com/zz/sokdb/AKontroller.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.zz.sokdb.apix.APixRepo' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Qualifier("apixEntityManager")}
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:797) ~[spring-beans-5.2.10.RELEASE.jar:5.2.10.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:227) ~[spring-beans-5.2.10.RELEASE.jar:5.2.10.RELEASE]
        at...
        at...
        at...

我尝试过：

class APixRepoImpl constructor(@PersistenceContext @org.springframework.beans.factory.annotation.Qualifier("apixEntityManager") var em: EntityManager)

现在出现错误：

***************************
APPLICATION FAILED TO START
***************************

Description:

Parameter 0 of constructor in com.zz.sokdb.AKontroller required a single bean,but 3 were found:
        - apixEntityManager: defined by method 'apixEntityManager' in class path resource [com/zz/sokdb/apix/APixDataSourceConfiguration.class]
        - eroEntityManager: defined by method 'eroEntityManager' in class path resource [com/zz/sokdb/ero/EroDataSourceConfiguration.class]
        - smpixEntityManager: defined by method 'smpixEntityManager' in class path resource [com/zz/sokdb/smpix/SMPixDataSourceConfiguration.class]


Action:

Consider marking one of the beans as @Primary,or using @Qualifier to identify the bean that should be consumed

当我在两个地方都尝试注解时，错误就和我只在AKontroller中尝试时一样。

这时我放弃了，请过来寻求帮助。

解决方法

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