创建名为“*****”的bean时出错：注入autowired依赖项失败

Question

I am programming my first Java EE Hibernate/Spring application and an error appeared:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void net.UserList.controller.UserController.setUserService(net.UserList.service.UserService); nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userService' defined in ServletContext resource [/WEB-INF/dispatcher-servlet.xml]: Cannot resolve reference to bean 'userDao' while setting bean property 'userDao'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDao' defined in ServletContext resource [/WEB-INF/dispatcher-servlet.xml]: Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: Could not initialize class net.UserList.dao.UserDaoImpl
    org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
    org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
    org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
......
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Thread.java:748)
root cause

org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void net.UserList.controller.UserController.setUserService(net.UserList.service.UserService); nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userService' defined in ServletContext resource [/WEB-INF/dispatcher-servlet.xml]: Cannot resolve reference to bean 'userDao' while setting bean property 'userDao'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDao' defined in ServletContext resource [/WEB-INF/dispatcher-servlet.xml]: Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: Could not initialize class net.UserList.dao.UserDaoImpl
    org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)
    org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
....
    java.lang.Thread.run(Thread.java:748)
root cause

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userService' defined in ServletContext resource [/WEB-INF/dispatcher-servlet.xml]: Cannot resolve reference to bean 'userDao' while setting bean property 'userDao'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDao' defined in ServletContext resource [/WEB-INF/dispatcher-servlet.xml]: Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: Could not initialize class net.UserList.dao.UserDaoImpl
    org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:336)
    org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:108)
...
    org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:484)
    org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    javax.servlet.GenericServlet.init(GenericServlet.java:158)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2555)
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2544)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Thread.java:748)
root cause

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDao' defined in ServletContext resource [/WEB-INF/dispatcher-servlet.xml]: Instantiation of bean failed; nested exception is java.lang.NoClassDefFoundError: Could not initialize class net.UserList.dao.UserDaoImpl
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1076)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1021)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
...
    java.lang.Thread.run(Thread.java:748)
root cause

java.lang.NoClassDefFoundError: Could not initialize class net.UserList.dao.UserDaoImpl
    sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:148)
    org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1069)
    ...
    org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2544)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Thread.java:748)

我的mvc-dispatcher-servlet.xml：

http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/mvc/spring-mvc.xsd“>

<context:component-scan base-package="net.UserList"/>

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/WEB-INF/pages/"/>
    <property name="suffix" value=".jsp"/>
</bean>

<!-- Database Information -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
      destroy-method="close">
    <property name="driverClassName" value="microsoft.sqlserver.jdbc.SQLServerDriver"/>
    <property name="url"
              value="jdbc:sqlserver://localhost:1433/UsersDB"/>
    <property name="username" value=********/>
    <property name="password" value=**********/>
</bean>

<!-- Hibernate 4 SessionFactory Bean definition -->
<bean id="hibernate4AnnotatedSessionFactory"
      class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="annotatedClasses">
        <list>
            <value>net.UserList.model.User</value>
        </list>
    </property>
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.SQLServer2012Dialect
            </prop>
            <prop key="hibernate.show_sql">true</prop>
        </props>
    </property>
</bean>

<!--BookDao and BookService beans-->
<bean id="userDao" class="net.UserList.dao.UserDaoImpl">
    <property name="sessionFactory" ref="hibernate4AnnotatedSessionFactory"/>
</bean>

<bean id="userService" class="net.UserList.service.UserServiceImpl">
    <property name="userDao" ref="userDao"/>
</bean>

<!--<bean id="userService" class="net.UserList.service.UserServiceImpl">->
<!-    <property name="" ref="userDao"/> ->
<!-</bean>-->

<!--property name="userDao" ref="userDao"/-->

<context:component-scan base-package="net.UserList"/>

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

<bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
    <property name="sessionFactory" ref="hibernate4AnnotatedSessionFactory"/>
</bean>

<mvc:default-servlet-handler/>
<mvc:annotation-driven/>

My "dao-class": 

package net.UserList.dao;

import net.UserList.model.User;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Repository;

import java.io.Serializable;
import java.util.List;
import java.util.logging.Logger;

@Repository
public class UserDaoImpl implements UserDao {

    private static final Logger logger = (Logger) LoggerFactory.getLogger(UserDaoImpl.class);
    private SessionFactory sessionFactory;

    public void setSessionFactory(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }

    public void addUser(User user) {
        Session session = this.sessionFactory.getCurrentSession();
        session.persist(user);
        logger.info("User add!");
    }

    public void editUser(User user) {
        Session session = this.sessionFactory.getCurrentSession();
        session.update(user);
        logger.info("User edit!");
    }

    public void removeUser(int id) {
        Session session = this.sessionFactory.getCurrentSession();
        User user = (User)session.load(User.class, new Integer(id));
        //session.update(user);

        if(user!=null) session.delete(user);

        logger.info("User removed!");
    }

    public User getUser(int id) {

        Session session = this.sessionFactory.getCurrentSession();
        User user = (User)session.load(User.class, new Integer(id));
        logger.info("User here!");

        return user;
    }

    @SuppressWarnings("unchecked")
    public List<User> ListUsers() {

        Session session = this.sessionFactory.getCurrentSession();
        List<User> list = session.createQuery("from User").list();

        for (User user:list) {
            logger.info("User: " + user);
        }

        return list;
    }
}

我的“控制器”：

package net.UserList.controller;

import net.UserList.model.User;
import net.UserList.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class UserController {

    private UserService userService;

    @Autowired(required = true)
    @Qualifier(value = "userService")
    public void setUserService(UserService userService) {
        this.userService = userService;
    }

    @RequestMapping(value = "users",method = RequestMethod.GET)
    public String userList(Model model){
         model.addAttribute("user", new User());
         model.addAttribute("listUsers",this.userService.ListUsers());

         return "users";
    }

    @RequestMapping(value = "/users/add",method = RequestMethod.POST)
    public String addUser(@ModelAttribute("user") User user){

        if (user.getId() ==0 ) {
            this.userService.addUser(user);
        } else {
            this.userService.editUser(user);
        }

        return "redirect:/users";
    }

    @RequestMapping("/remove/{id}")
    public String removeUser(@PathVariable("id") int id){
        this.userService.removeUser(id);
        return "redirect:/users";
    }

    @RequestMapping("/edit/{id}")
    public String idtUser(@PathVariable("id") int id,Model model){

        model.addAttribute("user",this.userService.getUser(id));
        model.addAttribute("listUsers",this.userService.ListUsers());

        return "users";

    }

    @RequestMapping("/userdata/{id}")
    public String userData(@PathVariable("id") int id,Model model){

        model.addAttribute("user",this.userService.getUser(id));

        return "userdata";
    }
}

Answer 1

移动这两个注释

<mvc:default-servlet-handler/>
<mvc:annotation-driven/> 

在组件扫描上方。

您还可以对组件进行两次扫描:

但我建议您将基于xml的配置更改为基于java的配置。它更容易（更直观）和更干净。有许多关于基于java的配置的教程。举个例子

未经测试的示例

package net.UserList;

@Configuration
@EnableTransactionManagement
@EnableWebMvc // replacement for <mvc:annotation-driven/>
@PropertySource({ "classpath:application.properties" })
@ComponentScan({ "net.UserList" }) // replacing <context:component-scan base-package="net.UserList"/>
public class ApplicationConfig extends WebMvcConfigurerAdapter {

   @Autowired
   private Environment env;

   // set default servlet handlers, same as <mvc:default-servlet-handler
   @Override
   public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
      configurer.enable();
   }

   @Bean
   public LocalSessionFactoryBean sessionFactory() {
      LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
      sessionFactory.setDataSource(restDataSource());
      sessionFactory.setPackagesToScan(
        new String[] { "net.UserList.model" });
      sessionFactory.setHibernateProperties(hibernateProperties());

      return sessionFactory;
   }

   @Bean
   public DataSource restDataSource() {
      BasicDataSource dataSource = new BasicDataSource();
      dataSource.setDriverClassName(env.getProperty("jdbc.driverClassName"));
      dataSource.setUrl(env.getProperty("jdbc.url"));
      dataSource.setUsername(env.getProperty("jdbc.user"));
      dataSource.setPassword(env.getProperty("jdbc.pass"));

      return dataSource;
   }

   @Bean
   @Autowired
   public HibernateTransactionManager transactionManager(
     SessionFactory sessionFactory) {

      HibernateTransactionManager txManager
       = new HibernateTransactionManager();
      txManager.setSessionFactory(sessionFactory);

      return txManager;
   }

   @Bean
   public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
      return new PersistenceExceptionTranslationPostProcessor();
   }

   Properties hibernateProperties() {
      return new Properties() {
         {
            setProperty("hibernate.hbm2ddl.auto",
              env.getProperty("hibernate.hbm2ddl.auto"));
            setProperty("hibernate.dialect",
              env.getProperty("hibernate.dialect"));
            setProperty("hibernate.globally_quoted_identifiers",
             "true");
         }
      };
   }
}

应用程序.属性

#jdbc
jdbc.driverClassName=microsoft.sqlserver.jdbc.SQLServerDriver
jdbc.url=jdbc:sqlserver://localhost:1433/UsersDB
jdbc.user=user
jdbc.pass=password

#hibernate
hibernate.dialect=org.hibernate.dialect.SQLServer2012Dialect
hibernate.show_sql=true

<servlet>
    <servlet-name>sample</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextClass</param-name>
        <param-value>
            org.springframework.web.context.support.AnnotationConfigWebApplicationContext
        </param-value>
    </init-param>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            net.UserList.ApplicationConfig
        </param-value>
    </init-param>
</servlet>
....