java - 不满意的依赖异常 : Error creating bean(by BeanNotOfRequiredTypeException)

Question

我尝试使用 Spring MVC 和 Hibernate 运行我的第一个 Web 应用程序，但我遇到了一些问题。

通用道:

@Repository
public abstract class GenericDao<T> implements GeneralDao<T> {

    private Class<T> className;

    protected GenericDao(Class<T> className) {
        this.className = className;
    }

    @PersistenceContext
    private EntityManager entityManager;

    public EntityManager getEntityManager() {
        return entityManager;
    }

    @Override
    public void add(T object) {
        try {
            getEntityManager().persist(object);
        } catch (HibernateException e) {
            throw new DaoException(ErrorMessage.MESSAGE_ADD_ENTITY_FAIL, e);
        }
    }

    @Override
    public void update(T object) {
        try {
            getEntityManager().merge(object);
        } catch (HibernateException e) {
            throw new DaoException(ErrorMessage.MESSAGE_UPDATE_ENTITY_FAIL, e);
        }
    }

    @Override
    public void remove(T object) {
        try {
            getEntityManager().remove(object);
        } catch (HibernateException e) {
            throw new DaoException(ErrorMessage.MESSAGE_REMOVE_ENTITY_FAIL, e);
        }
    }

    @Override
    public T getById(int id) {
        try {
            return getEntityManager().find(this.className, id);
        } catch (HibernateException e) {
            throw new DaoException(ErrorMessage.MESSAGE_GET_BY_ID_ENTITY_FAIL, e);
        }
    }

    public abstract List<T> getAll() throws DaoException;

}

用户道.java:

@Repository
public class UserDao extends GenericDao<User> {
    private final static String USER_LOGIN = "login";
    private final static String USER_PASSWORD = "password";

    private UserDao() {
        super(User.class);
    }

    @Override
    public List<User> getAll() {
        List<User> userList;
        try {
            userList = getEntityManager().createQuery(Statement.GET_ALL_USERS).getResultList();
        } catch (HibernateException e) {
            throw new DaoException(ErrorMessage.MESSAGE_GET_ALL_ENTITY_FAIL, e);
        }
        return userList;
    }

    public List<User> getByLoginAndPassword(String userLogin, String userPassword) {
        CriteriaQuery<User> criteriaQuery;
        try {
            CriteriaBuilder criteriaBuilder = getEntityManager().getCriteriaBuilder();
            criteriaQuery = criteriaBuilder.createQuery(User.class);
            Root<User> userRoot = criteriaQuery.from(User.class);
            criteriaQuery.select(userRoot);
            criteriaQuery.where(
                    criteriaBuilder.equal(userRoot.get(USER_LOGIN), userLogin),
                    criteriaBuilder.equal(userRoot.get(USER_PASSWORD), userPassword)
            );
        } catch (HibernateException e) {
            throw new DaoException(ErrorMessage.MESSAGE_GET_ENTITY_BY_LOGIN_AND_PASSWORD_FAIL, e);
        }
        return getEntityManager().createQuery(criteriaQuery).getResultList();
    }
}

通用服务.java:

@Service
public abstract class GenericService<T> implements GeneralService<T> {

    private static Logger logger = Logger.getLogger(GenericService.class);

    @Autowired
    private GenericDao<T> dao;

    @Transactional
    @Override
    public void add(T object) throws ServiceException {
        try {
           dao.add(object);
        } catch (DaoException e) {
            logger.debug(e);
            throw new ServiceException(e.getMessage());
        }
    }

    @Transactional
    @Override
    public void update(T object) throws ServiceException {
        try {
            dao.update(object);
        } catch (DaoException e) {
            logger.debug(e);
            throw new ServiceException(e.getMessage());
        }
    }

    @Transactional
    @Override
    public void remove(T object) throws ServiceException {
        try {
            dao.remove(object);
        } catch (DaoException e) {
            logger.debug(e);
            throw new ServiceException(e.getMessage());
        }
    }

    @Transactional(readOnly = true)
    @Override
    public T getById(int id) throws ServiceException {
        try {
            return dao.getById(id);
        } catch (DaoException e) {
            logger.debug(e);
            throw new ServiceException(e.getMessage());
        }
    }

    @Transactional(readOnly = true)
    @Override
    public List<T> getAll() throws ServiceException {
        try {
            return dao.getAll();
        } catch (DaoException e) {
            logger.debug(e);
            throw new ServiceException(e.getMessage());
        }
    }

}

用户服务.java:

@Service
public class UserService extends GenericService<User> {

    private static Logger logger = Logger.getLogger(UserService.class);

    @Autowired
    private UserDao userDao;

    @Transactional
    public String checkUser(String userLogin, String userPassword) throws ServiceException {
        String namePage = "errorAuthorization";
        List<User> userList;
        try {
           userList = userDao.getByLoginAndPassword(userLogin, userPassword);
        }  catch (DaoException e) {
            logger.debug(e);
            throw new ServiceException(e.getMessage());
        }
        if(userList.size() != 0) {
            return UserRoleChecker.defineUserPage(userList.get(0));
        }
        return namePage;
    }

    public void addUser(String userLogin, String userPassword, String userMail) throws ServiceException{
        Role role = new Role(0, RoleType.USER);
        User user = new User(0, userLogin, userPassword, userMail, role);
        add(user);
    }

}

用户 Controller .java:

@Controller
public class UserController {
    private static String className = UserController.class.getName();

    @Autowired
    private UserService userService;

    @RequestMapping(value = "/check_user", method = RequestMethod.POST)
    public ModelAndView authorizationUser(HttpServletRequest request, HttpServletResponse response) {
        ModelAndView modelAndView = new ModelAndView();
        String returnPage;
        try {
            returnPage = userService.checkUser(request.getParameter(RequestParameter.USER_LOGIN), request.getParameter(RequestParameter.USER_PASSWORD));
        } catch (ServiceException e) {
            returnPage = ErrorHandler.returnErrorPage(e.getMessage(), className);
        }
        modelAndView.setViewName(returnPage);
        return modelAndView;
    }

    @RequestMapping(value = "/add_user", method = RequestMethod.POST)
    public ModelAndView registrationUser(HttpServletRequest request, HttpServletResponse response) {
        ModelAndView modelAndView = new ModelAndView();
        String returnPage = Page.SUCCESSFUL_REGISTRATION;
        try {
            userService.addUser(request.getParameter(RequestParameter.USER_LOGIN), request.getParameter(RequestParameter.USER_PASSWORD), request.getParameter(RequestParameter.USER_MAIL));
        }  catch (ServiceException e) {
           returnPage = ErrorHandler.returnErrorPage(e.getMessage(), className);
        }
        modelAndView.setViewName(returnPage);
        return modelAndView;
    }

}

根上下文.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:c="http://www.springframework.org/schema/c"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:util="http://www.springframework.org/schema/util"
       xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.1.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd
        http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">

    <context:annotation-config />

    <context:component-scan base-package="by.netcracker.artemyev" />

    <bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource">
        <property name="url" value="jdbc:mysql://localhost:3306/airline?useSSL=false" />
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
        <property name="initialSize" value="5"/>
        <property name="maxTotal" value="10"/>
    </bean>

    <bean id="entityManager" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="packagesToScan" value="by.netcracker.artemyev" />
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                <property name="showSql" value="true" />
                <property name="database" value="MYSQL" />
                <property name="databasePlatform" value="org.hibernate.dialect.MySQL5Dialect" />
            </bean>
        </property>
        <property name="jpaProperties">
            <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="debug">true</prop>
                <prop key="connection.isolation">2</prop>
                <prop key="hibernate.cglib.use_reflection_optimizer">true</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
            </props>
        </property>
        <property name="jpaDialect" ref="jpaDialect" />
    </bean>

    <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

    <tx:annotation-driven transaction-manager="transactionManager" />

    <bean id="jpaDialect" class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />

    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManager" />
        <property name="dataSource" ref="dataSource" />
        <property name="jpaDialect" ref="jpaDialect" />
    </bean>

</beans>

日志:

org.springframework.web.context.ContextLoader 2017-05-09 11:48:21,198 ERROR - Context initialization failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userController': Unsatisfied dependency expressed through field 'userService'; nested exception is org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'userService' is expected to be of type 'by.netcracker.artemyev.service.UserService' but was actually of type 'com.sun.proxy.$Proxy31'
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
    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:761)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:443)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:325)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4744)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5206)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
    at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1702)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:456)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:405)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468)
    at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
    at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309)
    at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401)
    at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:324)
    at sun.rmi.transport.Transport$1.run(Transport.java:200)
    at sun.rmi.transport.Transport$1.run(Transport.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'userService' is expected to be of type 'by.netcracker.artemyev.service.UserService' but was actually of type 'com.sun.proxy.$Proxy31'
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.checkBeanNotOfRequiredType(DefaultListableBeanFactory.java:1503)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1482)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
    ... 60 more

问题:请解释为什么我会遇到这个问题以及如何解决这个错误？

Answer 1

这个问题的原始问题是通过从 UserDao 中删除 @Transactional 解决的，这是需要完成的，因为 Service 实现负责用于事务管理，而不是 DAO。

还建议从 UserDao 构造函数中删除 @Autowired，因为构造函数没有参数，即它没有 Autowiring 任何东西。

现在该问题已得到修复，代码在 UserController 的 userService 字段中也存在类似问题。

由于 Spring 使用代理模式，UserController 需要一个由 UserService 实现的接口(interface)，而不是类本身。

通常的做法是将类重命名为 UserServiceImpl，然后添加一个名为 UserService 的接口(interface)。继续让 UserController 类的字段 userService 为 UserService 类型。