【发布时间】：2016-08-23 20:10:09
【问题描述】：
我正在使用spring-data-jpa 进行一些测试，所以为了不创建新文件来执行存储库接口，我将其放在 Main 中，如下所示：
@SpringBootApplication
public class Application {
private static final Logger log = LoggerFactory.getLogger(Application.class);
public static void main(String[] args) {
SpringApplication.run(Application.class);
}
@Bean
public CommandLineRunner demo(BRepository repository) {
return (args) -> {
log.info("Insert a");
repository.save(new EntityA("TestA"));
log.info("Find a " + repository.findOne(1));
};
}
@Entity
@Table(name = "A")
public static class EntityA{
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private Integer id;
@Column(name = "NAME")
private String name;
//Getters, setters && constructors
}
public interface BRepository extends CrudRepository<EntityA, Integer> {
}
}
然后我用@BeanCommandLineRunner对其进行了测试以查看输出，但我得到了UnsatisfiedDependencyException：
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'demo' defined in hello.Application: Unsatisfied dependency expressed through method 'demo' parameter 0: No qualifying bean of type [hello.Application$BRepository] found for dependency [hello.Application$BRepository]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [hello.Application$BRepository] found for dependency [hello.Application$BRepository]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:467) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1123) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:776) ~[spring-beans-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:861) ~[spring-context-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541) ~[spring-context-4.3.2.RELEASE.jar:4.3.2.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:369) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:313) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1185) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1174) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
at hello.Application.main(Application.java:27) [classes/:na]
最后，为了确保我没有做错什么，我在一个新文件中对接口存储库进行了测试，它可以工作。
有人知道为什么不使用内部接口的存储库吗？
这是一个问题还是由于某种原因不起作用？ （或者也许我做错了什么）
【问题讨论】：
-
将
org.springframework.stereotype包中的@Repository注释放在您的BRepository接口上。 -
它不适用于
@Repository...同样的异常。 -
您是否尝试使用
@EnableAutoConfiguration和@ComponentScan注释来注释您的Application类？ -
它用
@SpringBootApplication注释，由@EnableAutoConfiguration、@ComponentScan、@SpringBootConfiguration、.. 和我试过@EnableJpaRepositories组成，但也不起作用。 . -
让它成为一个嵌套类有什么意义呢？根据规范，它确实应该是一个顶级接口，实体也不能是嵌套类。即使这是一个错误/限制，我认为它不值得修复：正确的做法是将其定义为顶级接口。
标签： java spring-boot spring-data spring-data-jpa