java - 如何在 Spring JPA 中注入(inject) CrudRepository？

Question

我想使用 spring-data-jpa 和 CrudRepository<T, ID extends Serializable> .但我不能让它自动接线。 (同一包中的所有其他服务均已正确连接):

@Service
public class UserService {
    @Resource
    private UserRepo repo;

    //this does neither work
    //@Autowired
    //private CrudRepository<User, Long> repo;

}

public interface UserRepo extends CrudRepository<User, Long> {

}

@Entity
public class User {
    @Id
    private Long id;
} 

结果:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userService': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [UserRepo] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@javax.annotation.Resource(shareable=true, mappedName=, description=, name=, type=class java.lang.Object, lookup=, authenticationType=CONTAINER)}

这里可能有什么问题？

从文档中我认为它应该可以在不编写实现的情况下工作:

In a typical Java application, you’d expect to write a class that implements CustomerRepository. But that’s what makes Spring Data JPA so powerful: You don’t have to write an implementation of the repository interface. Spring Data JPA creates an implementation on the fly when you run the application.

---

更新 SpringConfig:

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories("my.package")
public class AppConfig {

    @Bean
    public LocalContainerEntityManagerFactoryBean emf() throws ClassNotFoundException, PropertyVetoException {
        LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
        emf.setDataSource(dataSource());
        emf.setPackagesToScan("my.package");
        emf.setJpaVendorAdapter(jpaAdapter());
        emf.setJpaProperties(jpaProterties());
        return emf;
    }
}

结果:缺少 emf，这很奇怪，因为我已经有了可以 Autowiring 的 DAO 服务 EntityManager和 EMF没有任何问题。

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#1a6e658': Cannot resolve reference to bean 'entityManagerFactory' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'entityManagerFactory' is defined
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:336)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:108)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:632)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:442)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1094)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:989)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:276)
    ... 50 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'entityManagerFactory' is defined
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:641)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1159)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:282)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:328)
    ... 58 more

Answer 1

您应该验证以下内容:

1) 使用 @Repository 注释 UserRepo。

2) 你的 spring beans xml 文件应该包含在其中:

<jpa:repositories base-package="your.repository.package"></jpa:repositories>

3) 我建议使用 @Autowired 而不是 @Resource

注入(inject)这种类型的 bean

更新

看来你完成了我的前 3 步，而你现在领先一步。现在，请记住，在 Java Config 方法中，名称 DO 很重要。将 emf() 更改为 entityManagerFactory() (更“标准”)，或将 entity-manager-factory-ref 设置为 emf。示例:

@Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() throws ClassNotFoundException, PropertyVetoException {
        LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
        emf.setDataSource(dataSource());
        emf.setPackagesToScan("my.package");
        emf.setJpaVendorAdapter(jpaAdapter());
        emf.setJpaProperties(jpaProterties());
        return emf;
    }