EntityManager在DAO类中为null

Question

我正在尝试使用Java Spring和hibernate构建一个应用程序。 对于dao类我正在使用泛型dao模式。当我尝试执行查询时，抛出nullpointer异常，因为entityManager为null。我认为它没有正确注入，但我不知道为什么。

申请背景：

<?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:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">

    <bean id = "klantDao" class="service.JpaKlantDao"/>
    <bean id="userDao" class="service.JpaUserDao"/>
    <bean id="assembler" class="service.Assembler" />
</beans>

Dispatcher servlet：

<?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:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:jee="http://www.springframework.org/schema/jee"
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/aop 
       http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
       http://www.springframework.org/schema/tx 
       http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
       http://www.springframework.org/schema/mvc
       http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
       http://www.springframework.org/schema/context 
       http://www.springframework.org/schema/context/spring-context-3.0.xsd
     http://www.springframework.org/schema/jee
     http://www.springframework.org/schema/jee/spring-jee-3.0.xsd">

    <mvc:annotation-driven />
    <context:component-scan base-package="controllers"/>
    <context:component-scan base-package="service"/>
    <mvc:resources mapping="/resources/**" location="/resources/" />
    <jee:jndi-lookup id="dataSource" jndi-name="jdbc/CentricJavaDB"/>
    <bean id="entityManagerFactory"
          class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="packagesToScan">
            <list>
                <value>domain</value>
            </list>
        </property>
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                <property name="showSql" value="true" /> 
                <property name="generateDdl" value="true" />
                <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect"/> 
             </bean>
        </property>
    </bean>

    <bean id="transactionManager" 
          class=" org.springframework.orm.jpa.JpaTransactionManager ">
        <constructor-arg ref="entityManagerFactory" />
    </bean>

    <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true"/>

    <bean id="viewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver"
          p:prefix="/WEB-INF/jsp/"
          p:suffix=".jsp" />

    <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
        <property name="basename" value="mymessages" />
    </bean>
</beans>

Web.xml中：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.1" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /WEB-INF/applicationContext.xml,
            /WEB-INF/spring-security.xml
        </param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>2</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>*.htm</url-pattern>
    </servlet-mapping>
    <!--Spring Security Configuration-->
    <filter>
        <filter-name>springSecurityFilterChain</filter-name>
        <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>overzicht.jsp</welcome-file>
    </welcome-file-list>
</web-app>

我注入dao的控制器：

@Controller
public class LoginController {

    @Autowired
    private KlantDao klantDao;

    @RequestMapping(value="/login", method = RequestMethod.GET)
    public String klantInloggen(Model model) 
    {
        String k;
        k = klantDao.findAll().get(0).getEmailadres();
        return "login";
    }
}

通用dao界面：

public interface GenericDao<T> {

    public List<T> findAll();
    public T update(T object);
    public T get(Long id);
    public void delete(T object);
    public void insert(T object);
    public boolean exists(Long id) ;
}

通用dao实现：

@Transactional
public class JpaGenericDao<T> implements GenericDao<T> {

    private Class<T> type;

    private EntityManager em;

    public JpaGenericDao(Class<T> type) {
        super();
        this.type = type;
    }

    @PersistenceContext
    public void setEntityManager(EntityManager em) {
        this.em = em;
    }

    @Transactional(readOnly = true)
    @Override
    public T get(Long id) {
        T entity = this.em.find(this.type, id);
        return entity;
    }

    @Transactional(readOnly = true)
    @Override
    public List<T> findAll() {
        return this.em.createQuery(
                "select entity from " + this.type.getName() + " entity").getResultList();
    }

    //@Transactional
    @Override
    public void insert(T object) {
        em.persist(object);
    }

    //@Transactional
    @Override
    public void delete(T object) {
        em.remove(em.merge(object));
    }

    @Transactional(readOnly = true)
    @Override
    public boolean exists(Long id) {
        T entity = this.em.find(this.type, id);
        return entity != null;
    }

    @Override
    public T update(T object) {
        return em.merge(object);
    }
}

Klant dao界面：

public interface KlantDao
{       
    public List<Klant> findAll();       
}

klant dao实施：

public class JpaKlantDao extends JpaGenericDao<Klant> implements KlantDao
{
    public JpaKlantDao()
    {
        super(Klant.class);
    }
}

我希望有人可以帮助我，我已经调试了几个小时，我找不到我做错了什么。