Java Spring注解错误

Question

我正在使用 Spring MVC 编写一个 Web 应用程序，我遇到了一个错误，我不知道是什么原因导致的。

我一直在寻找任何解决方案，但添加像 @Component 这样的注释没有帮助。

类的代码如下:

存储库类:

@Repository("UserRepository")
public interface UserRepository extends JpaRepository<User, Integer> {

@Query("Insert INTO User Values(email,password)")
public User AddUser(@Param("email") String email, @Param("password") String password);
}

Controller 类:

@RestController
public class UserActionController {



private UserRepository userservice;

@Autowired
public  UserActionController(UserRepository userservice)
{
    this.userservice = userservice;
}


@RequestMapping(value = { "/zaloguj" }, method = RequestMethod.GET)
public ModelAndView logowanie(@RequestParam String action) {

    ModelAndView model = new ModelAndView();
    model.addObject("title", "Injected MVC title");
    model.addObject("message", "This is default page!");
    model.setViewName("zaloguj");   
    userservice.AddUser("test", "test");
    return model;
}
}

错误:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userActionController' defined in file [C:\Users\bartlomiej.zuk\workspaceEclipse4\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\examplespringproject\WEB-INF\classes\com\mkyong\web\controller\UserActionController.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [com.mkyong.dao.UserRepository]: : No qualifying bean of type [com.mkyong.dao.UserRepository] found for dependency: 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 [com.mkyong.dao.UserRepository] found for dependency: 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)
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:185)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1143)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:838)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:537)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:446)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:328)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4791)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5236)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1408)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.mkyong.dao.UserRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1373)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1119)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1014)
at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:813)
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741)
... 24 more

Answer 1

No qualifying bean of type [com.mkyong.dao.UserRepository]

这意味着 spring 无法实例化 UserRepository。您应该以某种方式告诉 spring 您的 repositories 位置在哪里。例如，您应该有一个如下所示的数据访问配置:

@Configuration
@EnableJpaRepositories(basePackages="com.mkyong.dao")
public class DataConfig {
    // Put your DataSource, EntityManagerFactory, PlatformTransactionManager, etc here
}

basePackages="com.mkyong.dao" 告诉 spring 容器在 com.mkyong.dao 包中寻找存储库。此外，当您使用 Spring Data 时，不需要 @Repository 注释。