如何注释自定义Spring Boot自定义存储库？

Question

我有一个名为Screenshot的实体类和一个声明为以下内容的存储库：

public interface ScreenshotRepository extends JpaRepository<Screenshot, UUID>, ScreenshotRepositoryCustom

定制存储库的定义如下：

interface ScreenshotRepositoryCustom

和

class ScreenshotRepositoryImpl implements ScreenshotRepositoryCustom {
    private final ScreenshotRepository screenshotRepo;

    @Autowired
    public ScreenshotRepositoryImpl(ScreenshotRepository screenshotRepo) {
        this.screenshotRepo = screenshotRepo;
    }

这是在另一个堆栈溢出问题中描述的内容： 如何向Spring Data JPA添加自定义方法

现在，IntelliJ给我警告：

Autowired members must be defined in a valid Spring bean

我尝试将这些注释添加到ScreenshotRepositoryImpl但没有一个起作用：

• @Repository
• @Component
• @Service

但无济于事。 显然有些错误，但我正在尝试。 什么是正确的注释。

使用@Repository ，出现此错误：

2017-11-23 12:30:04.064  WARN 20576 --- [  restartedMain] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'screenshotsController' defined in file [C:\Users\pupeno\Documents\Dashman\java\dashmanserver\out\production\classes\tech\dashman\server\controllers\ScreenshotsController.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'screenshotRepositoryImpl' defined in file [C:\Users\pupeno\Documents\Dashman\java\dashmanserver\out\production\classes\tech\dashman\server\models\ScreenshotRepositoryImpl.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'screenshotRepositoryImpl': Requested bean is currently in creation: Is there an unresolvable circular reference?
2017-11-23 12:30:04.064  INFO 20576 --- [  restartedMain] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
2017-11-23 12:30:04.064  INFO 20576 --- [  restartedMain] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2017-11-23 12:30:04.080  INFO 20576 --- [  restartedMain] utoConfigurationReportLoggingInitializer : 

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2017-11-23 12:30:04.080 ERROR 20576 --- [  restartedMain] o.s.b.d.LoggingFailureAnalysisReporter   : 

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

Description:

The dependencies of some of the beans in the application context form a cycle:

   screenshotsController defined in file [C:\Users\pupeno\Documents\Dashman\java\dashmanserver\out\production\classes\tech\dashman\server\controllers\ScreenshotsController.class]
┌─────┐
|  screenshotRepositoryImpl defined in file [C:\Users\pupeno\Documents\Dashman\java\dashmanserver\out\production\classes\tech\dashman\server\models\ScreenshotRepositoryImpl.class]
└─────┘

Answer 1

怎么了？

您的依存关系形成一个循环： ScreenshotRepository扩展了ScreenshotRepositoryCustom ，但是ScreenshotRepositoryCustom实现依赖于ScreenshotRepository 。 由于这个周期，所有Bean都无法完成其实例化。

拟议的解决方案

在这些情况下，Spring Data不支持通过构造函数进行注入。 尝试这样做将导致依赖周期错误。 为了能够将ScreenshotRepository注入ScreenShotRepositoryImpl ，您需要通过field进行注入：

@Repository
public class ScreenshotRepositoryImpl implements ScreenshotRepositoryCustom {

    @Autowired
    ScreenshotRepository screenshotRepository ;

    ...

}