如何在春季JPA中注入CrudRepository？

java spring spring-data-jpa

2022-09-03 02:01:58

我想利用 spring-data-jpa 和 .但我不能让它自动布线。（同一软件包中的所有其他服务都已正确连接）：CrudRepository<T, ID extends Serializable>

@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：创建名为“userService”的bean时出错：注入资源依赖性失败;嵌套的例外是 org.springframework.beans.factory.NoSuchBeanDefinitionException：没有找到用于依赖项的 [UserRepo] 类型的合格 Bean：预期至少有 1 个 Bean 有资格作为此依赖项的自动连接候选项。Dependency annotations： {@javax.annotation.Resource（shareable=true， mappedName=， description=， name=， type=class java.lang.Object， lookup=， authenticationType=CONTAINER）}

这里可能出了什么问题？

从文档中，我认为它应该在不编写实现的情况下工作：

在典型的 Java 应用程序中，您需要编写一个实现 CustomerRepository 的类。但这就是Spring Data JPA如此强大的原因：您不必编写存储库接口的实现。Spring Data JPA 会在您运行应用程序时动态创建一个实现。

更新的弹簧配置：

@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：电动势丢失，这很奇怪，因为我已经有工作DAO系列，我可以在其中自动布线并且没有任何问题。EntityManagerEMF

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

答案 1

您应验证以下内容：

1）用注释。UserRepo@Repository

2）你的弹簧豆xml文件应该有：

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

3）我建议将这种类型的豆子注入而不是@Autowired@Resource

更新

看来你做了我的前3步，你现在领先了一步。现在，请记住，在 Java Config 中，方法名称确实很重要。要么更改为（更“标准”），要么设置为。例：emf()entityManagerFactory()entity-manager-factory-refemf

@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;
    }

答案 2

用户存储库不需要用：

 @Repository