Question

这是我第一次使用Spring MVC尝试Spring Data JPA，但我无法解决此错误。

错误记录

SEVERE：将上下文初始化事件发送到类org.springframework.web.context.ContextLoaderListener的侦听器实例的异常 org.springframework.beans.factory.UnsatisfiedDependencyException：创建名为'mainController'的bean时出错：通过字段'userRepository'表示的不满意的依赖关系;嵌套异常是org.springframework.beans.factory.NoSuchBeanDefinitionException：没有'com.example.repo.UserRepository'类型的限定bean可用：预期至少有1个bean可以作为autowire候选者。依赖注释：{@ org.springframework.beans.factory.annotation.Autowired（required = true）} 在org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor $ AutowiredFieldElement.inject（AutowiredAnnotationBeanPostProcessor.java:588）在org.springframework.beans.factory.annotation.InjectionMetadata.inject（InjectionMetadata.java:88）在org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues（AutowiredAnnotationBeanPostProcessor.java:366）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean（AbstractAutowireCapableBeanFactory.java:1264）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:553）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean（AbstractAutowireCapableBeanFactory.java:483） at org.springframework.beans.factory.support.AbstractBeanFactory $ 1.getObject（AbstractBeanFactory.java:306）在org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton（DefaultSingletonBeanRegistry.java:230）在org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（AbstractBeanFactory.java:302）在org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:197）在org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons（DefaultListableBeanFactory.java:761） at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization（AbstractApplicationContext.java:866）在org.springframework.context.support.AbstractApplicationContext.refresh（AbstractApplicationContext.java:542）在org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext（ContextLoader.java:444）在org.springframework.web.context.ContextLoader.initWebApplicationContext（ContextLoader.java:326）在org.springframework.web.context.ContextLoaderListener.contextInitialized（ContextLoaderListener.java:107） at org.apache.catalina.core.StandardContext.listenerStart（StandardContext.java:4725） at org.apache.catalina.core.StandardContext.startInternal（StandardContext.java:5189）在org.apache.catalina.util.LifecycleBase.start（LifecycleBase.java:150）在org.apache.catalina.core.ContainerBase $ StartChild.call（ContainerBase.java:1419）在org.apache.catalina.core.ContainerBase $ StartChild.call（ContainerBase.java:1409） at java.util.concurrent.FutureTask.run（FutureTask.java:266）在java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1142） at java.util.concurrent.ThreadPoolExecutor $ Worker.run（ThreadPoolExecutor.java:617）在java.lang.Thread.run（Thread.java:745）引起：org.springframework.beans.factory.NoSuchBeanDefinitionException：没有'com.example.repo.UserRepository'类型的限定bean可用：预期至少有1个bean可以作为autowire候选者。依赖注释：{@ org.springframework.beans.factory.annotation.Autowired（required = true）} 在org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound（DefaultListableBeanFactory.java:1486） at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency（DefaultListableBeanFactory.java:1104）在org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency（DefaultListableBeanFactory.java:1066） at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor $ AutowiredFieldElement.inject（AutowiredAnnotationBeanPostProcessor.java:585） ......还有24个

UserRepository.java

 @Repository
 public interface UserRepository extends CrudRepository<User, Integer> {

 }

MainController.java

@Controller
@RequestMapping("/")
public class MainController {

    @Autowired
    private UserRepository userRepository;

    @RequestMapping(value = "/user", method = RequestMethod.POST, headers = "Accept=application/json")
    @ResponseBody
    public ResponseEntity<User> addUser(@RequestBody User user) {
        userRepository.save(user);
        System.out.println("------>>>>>>>>>>" + user.getName());
        HttpHeaders headers = new HttpHeaders();
        return new ResponseEntity<User>(headers, HttpStatus.OK);
    }

    @RequestMapping(value = "/user/list", method = RequestMethod.GET)
    public ResponseEntity<List<User>> listAllUsers() {
        List<User> users = (List<User>)userRepository.findAll();
        if (users.isEmpty()) {
            System.out.println("List is empty oops..!!");
            return new ResponseEntity<List<User>>(HttpStatus.NO_CONTENT);
        }
        System.out.println("Got the List...!!");
        System.out.println("Name of First User---->>>>" + users.get(0).getName());
        return new ResponseEntity<List<User>>(users, HttpStatus.OK);
    }

}

AppConfig.java

@Configuration
@ComponentScan("com.example")
@EnableWebMvc
@EnableJpaRepositories
@EnableTransactionManagement
public class AppConfig {

    @Bean
    public InternalResourceViewResolver viewResolver(){
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();  
        resolver.setPrefix("/WEB-INF");  
        resolver.setSuffix(".html");
        return resolver;  
    }

    @Bean
    public DataSource dataSource(){
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost:3306/spring_database");
        dataSource.setUsername("root");
        dataSource.setPassword("");
        return dataSource;
    }

    @Bean
    public EntityManagerFactory entityManagerFactory(){
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setShowSql(true);
        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setJpaVendorAdapter(vendorAdapter);
        factory.setPackagesToScan(User.class.getPackage().getName());
        factory.setDataSource(dataSource());
        factory.afterPropertiesSet();
        return factory.getObject();
    }

    @Bean
    public PlatformTransactionManager transactionManager(){
        JpaTransactionManager txManager = new JpaTransactionManager();
        txManager.setEntityManagerFactory(entityManagerFactory());
        return txManager;
    }

}

User.java

@Entity
@Table(name="user")
public class User {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Integer id;
    private String name;
    private String email;
    /*Getters and Setters*/

这是我的项目结构

Project Structure

我在这里缺少什么？或者我在这里犯了什么错误？任何人都可以解决这个问题吗？

Answer 1

您需要告诉spring在哪里寻找存储库：

@EnableJpaRepositories(basePackageClasses = UserRepository.class)

没有'com.example.repo.UserRepository'类型的限定bean可用

1 个答案: