如何在Spring JPA中注入CrudRepository? [英] How to inject CrudRepository in Spring JPA?

问题描述

我想使用spring-data-jpa和CrudRepository<T, ID extends Serializable>.但是我无法自动接线. (同一包中的所有其他服务均已正确接线):

I'd like to make use of spring-data-jpa and CrudRepository<T, ID extends Serializable>. But I cannot get it autowired. (all other services in the same package are wired correctly):

@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:

由以下原因引起:org.springframework.beans.factory.BeanCreationException: 创建名称为"userService"的bean时出错:注入资源 依赖项失败；嵌套的异常是 org.springframework.beans.factory.NoSuchBeanDefinitionException:否 发现类型为[UserRepo]的合格Bean具有依赖关系:预期为 至少1个符合此条件的自动装配候选豆 依赖性.依赖注释: {@ javax.annotation.Resource(shareable = true，mappedName =，description =， name =，type = class java.lang.Object，lookup =， authenticationType = CONTAINER)}

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)}

这可能是什么问题?

在文档中，我认为它无需编写实现即可工作:

From the docs I think it should work without writing an implementation:

在典型的Java应用程序中，您希望编写一个类， 实现CustomerRepository.但这就是Spring Data JPA的原因 如此强大:您不必编写 存储库接口. Spring Data JPA在 运行应用程序时飞起来.

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.

---

更新的SpringConfig:

---

Updated 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，因为我已经有可以正常使用EntityManager和EMF进行自动接线的DAO服务.

Result: emf is missing, which is strange as I already have working DAO serices where I can autowire EntityManager and EMF without any problem.

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

推荐答案

您应验证以下内容:

1)用@Repository注释UserRepo.

2)您的spring bean xml文件应包含在其中:

2) Your spring beans xml file should have in it:

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

3)我建议用@Autowired而不是@Resource

3) I'd recommend injecting this type of bean with @Autowired instead of @Resource

更新

看来您已经完成了我的前三步，而现在又领先了一步.现在，请记住，在Java Config方法中，名称 DO 很重要.可以将emf()更改为entityManagerFactory()(更标准")，或者将entity-manager-factory-ref设置为emf.示例:

it seems you did my first 3 steps and you're one step ahead now. Now, remember that in Java Config methods names DO matter. Either change emf() to entityManagerFactory() (which is more "standard"), or set entity-manager-factory-ref to emf. Example:

@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;
    }

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