带Hibernate的Spring-MVC；getCurrentSession（）时的嵌套异常为java.lang.NullPointerException

我发现这个错误很严重：路径为[/org]的上下文中Servlet[appServlet]的Servlet.service（）引发了异常[Request processing failed；嵌套异常为java.lang.NullPointerException]，其根本原因是

java.lang.NullPointerException
    at com.aquicktrack.controller.RegistrationDao.insertCustomer(RegistrationDao.java:31)
    at com.aquicktrack.org.StratUpController.getRegistration(StratUpController.java:32)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)

我的Spring配置文件

<!-- JDBC Data Source. It is assumed you have MySQL running on localhost 
        port 3306 with username root and blank password. Change below if it's not 
        the case -->
    <bean id="myDataSource" class="org.apache.tomcat.dbcp.dbcp2.BasicDataSource"
        destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/study" />
        <property name="username" value="root" />
        <property name="password" value="" />
        <property name="validationQuery" value="SELECT 1" />
    </bean>

    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="myDataSource" />
        <property name="packagesToScan" value="com.aquicktrack.com.entities" />
        <property name="hibernateProperties">
            <props>

                <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.hbm2ddl.auto">create</prop>
            </props>
        </property>
    </bean>

    <!-- Hibernate Transaction Manager -->
    <bean id="transactionManager"
        class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>

    <!-- Activates annotation based transaction management -->
    <tx:annotation-driven transaction-manager="transactionManager" />

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当我想从会话工厂类获取当前会话时，它会根据注释抛出它：

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让我猜猜，在您的控制器中，您改为执行新的注册dao（） 使用spring托管实例的方法戴纳姆

---

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是的，我正在创建这个类的一个实例，并使用 对象–Ashish Srivastava

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问题是Spring将只注入Spring管理的bean*。使用

new

创建对象时，它不是Spring管理的Bean

因此，将

@Repository

注释添加到DAO中，并通过添加带有

@Autowird

注释的字段将DAO注入控制器，然后使用它代替

新DAO

@Repository
public class YourDAO{
    @Autowired
    private SessionFactory sessionFactory;
    ...

    @Transactional
    public void insertCustomer(){...}
}

@Controller
public class YourController{
    @Autowired
    private YourDao yourDao;

    ... {
       this.yourDao.insertCustomer();
    }
}

---

*

This one Session Session=This.sessionFactory.getCurrentSession（）；SessionFactory注入是否正确？事实上，我是Spring MVC和Hibernate的新手，我不知道如何在控制台中使用我的实体类create Database正确运行此bt Hibernate让我猜在您的控制器中您是否执行

new RegistrationDao（）

而不是使用spring托管实例。是的，我正在创建此类的实例，并使用objectGetting调用该方法。此错误无法自动关联字段：com.aquicktrack.controller.RegistrationDao com.aquicktrack.org.StratUpController.registrationdoa；嵌套异常为org.springframework.beans.factory.NoSuchBeanDefinitionException:找不到依赖项类型为[com.aquicktrack.controller.RegistrationDao]的合格bean：至少需要1个符合此依赖项autowire候选项条件的bean。依赖项注释：{@org.springframework.beans.factory.annotation.Autowired（required=true）}您需要配置Spring，使其组件扫描也扫描包含您的DAO的包。转到下一步，但现在我收到此错误HTTP状态500-请求处理失败；嵌套异常为org.hibernate.HibernateException:未找到当前线程的会话new problem，new question:这与此问题不再相关，因此请询问一个新问题，并发布相关代码。

@Repository
public class YourDAO{
    @Autowired
    private SessionFactory sessionFactory;
    ...

    @Transactional
    public void insertCustomer(){...}
}

@Controller
public class YourController{
    @Autowired
    private YourDao yourDao;

    ... {
       this.yourDao.insertCustomer();
    }
}