没有定义类型 [javax.persistence.EntityManagerFactory] 的唯一 bean：预期单个 bean，但找到 0：答案

【问题标题】：No unique bean of type [javax.persistence.EntityManagerFactory] is defined: expected single bean but found 0:没有定义类型 [javax.persistence.EntityManagerFactory] 的唯一 bean：预期单个 bean，但找到 0：
【发布时间】：2013-01-11 22:28:12
【问题描述】：

我将 springframework 3.2 与 jboss server 7.1 一起使用。尝试使用 jpa2(hibernate provider, mysql) 和 spring mvc 设置一个简单的 spring 应用程序。

我使用了一个简单的 DAO，我在家庭控制器中注入了自动装配注释。这个 dao 类只是有一个字段（em）用于 persistentContext 被注入，它可能更简单，我不使用persistence.xml，因为从 3.1 版及更高版本的 spring 不需要......请注意，包被扫描适当地我已经尝试了网络上发布的其他解决方案的所有内容（包括这里）...... 但我收到此错误：

org.springframework.beans.factory.BeanCreationException: 不能自动装配字段：com.stko.home.model.daos.UserDao com.stko.home.controllers.HomeController.userDao；嵌套异常是 org.springframework.beans.factory.BeanCreationException：错误创建名为“userDao”的bean：注入持久性依赖失败；嵌套异常是 org.springframework.beans.factory.NoSuchBeanDefinitionException: 否 [javax.persistence.EntityManagerFactory] 类型的唯一 bean 是定义：预期的单个 bean，但发现 0： org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:514) org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87) org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:285) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1120) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:522) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:461) org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295) org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223) org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292) org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:607) org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932) org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479) org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:647) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:598) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:661) org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:517) org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:458) org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:138) javax.servlet.GenericServlet.init(GenericServlet.java:242) org.jboss.as.jpa.interceptor.WebNonTxEmCloserValve.invoke(WebNonTxEmCloserValve.java:50) org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:153) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:368） org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:671) org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930) java.lang.Thread.run(Thread.java:722)

我的 applicationContext.xml：

<bean class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close" id="dataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost:3306/mmydb"/>
    <property name="username" value="user"/>
    <property name="password" value="1234"/>
</bean>

<bean class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />

<bean id="entityManagerFactory"
        class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" >

<property name="dataSource" ref="dataSource"/>
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"/>
    </property>


    <property name="packagesToScan" value="com.stko.home.model.entities"/>

            <property name="jpaProperties">
                <props>
                    <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
                    <prop key="hibernate.max_fetch_depth">3</prop>
                    <prop key="hibernate.show.sql">true</prop>
                    <prop key="hibernate.connection.charSet"> UTF-8</prop>
                </props>

            </property>
        </bean>

<!--  tell spring to use annotation based congfigurations -->
<context:annotation-config />

 <!-- scan for beans -->
<context:component-scan base-package="com.stko.home.model.daos"/>

<!-- to recognize persistnce annotations like PersistenceContext -->
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>
<tx:annotation-driven transaction-manager="transactionManager" />

<bean id="databaseProperties" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:database.properties"/>
</bean>

我的 servlet-context.xml：

<!-- Enables the Spring MVC @Controller programming model -->
<annotation-driven />

<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
<resources mapping="/resources/**" location="/resources/" />

<!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
<beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <beans:property name="prefix" value="/WEB-INF/views/" />
    <beans:property name="suffix" value=".jsp" />
</beans:bean>


<context:component-scan base-package="com.stko.home"/>

我的 web.xml：

<!-- The definition of the Root Spring Container shared by all Servlets and Filters -->
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/spring/root-context.xml</param-value>
</context-param>

<!-- Creates the Spring Container shared by all Servlets and Filters -->
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<!-- Processes application requests -->
<servlet>
    <servlet-name>appServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/spring/appServlet/servlet-context.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>appServlet</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

我的用户道：

@Service("userDao")
@Repository
public class UserDao implements Serializable {
  @PersistenceContext
  private EntityManager em;

  @Transactional
  public  void saveUser(User user) {
  if(user!=null)
   em.persist(user);
  }

}

我的实体类用户：

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

   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   @Column(name = "userid")
   private Integer userid;

   @Column(name="username")
   private String username;
   public User(){}
   }

我的典型家庭控制器：

@Controller
public class HomeController {
.....

@Autowired
UserDao userDao;

@RequestMapping(value = "/", method = RequestMethod.GET)
public String home(Locale locale, Model model) {

.....


User newUser = new User();
newUser.setName("blabla");

userDao.saveUser(newUser);

return "home";
} 

}

【问题讨论】：

标签： spring hibernate jpa-2.0

【解决方案1】：

您是否有一个在其中定义了持久性单元的 persistence.xml？

【讨论】：

我这样做了...我有一个这样的文件，并且还在 applicationContext.xml 中的 LocalContainerEntityManagerFactoryBean 声明中使用持久性单元属性将持久性单元名称与 EntityManagerFactory 连接起来。还尝试在@persistenceContext 注释中使用单元名称......以及更多组合......但是spring不需要像以前那样的文件......

【解决方案2】：

问题很可能是servlet-context.xml 文件中的这一行：

<context:component-scan base-package="com.stko.home"/>

这实质上是试图在您的 Web 应用程序上下文中再次创建您的 DAO。你应该有一个过滤器，它只在这里创建你的控制器，这样：

<context:component-scan base-package="com.stko.home">
<context:include-filter expression="org.springframework.stereotype.Controller" type="annotation" />
</context:component-scan>

【讨论】：

我刚试过，但我仍然得到同样的错误。 :(（我使用 maven 进行包（之前总是使用 clean 以避免意外）以及 jboss 管理控制台进行部署。）它尝试重新创建 entityManagerFactory bean，或者找不到？异常消息接缝误导了我，比较与堆栈中的先前问题.....
它还说...预期单个 bean 但发现 0: 零..？

【解决方案3】：

试试这个

<bean class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" id="entityManagerFactory">
    <property name="persistenceUnitName" value="persistenceUnit"/>
    <property name="dataSource" ref="dataSource"/>
    <property name="jpaDialect">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />
    </property>
</bean>

为您的 EMF bean 定义属性，persistenceUnit 应该是您在 persistence.xml 中声明的名称

【讨论】：