Java 使用筛选器时自动连线问题

我使用的是筛选器类，但在自动连接会话工厂空指针异常期间，我的代码如下：

@Repository
public class UrlDaoImpl implements UrlDao{

    @Autowired
    SessionFactory sessionFactory;

    @Override
    public MerchnatDetails getMerchantByUrl(String enterdUrl) {




    MerchnatDetails merDetails=null;

    try{
        System.out.println("inside Dao");



    merDetails=new MerchnatDetails();
    Session session=sessionFactory.openSession();

    session=sessionFactory.getCurrentSession();
    Criteria  criteria=session.createCriteria(MerchnatDetails.class);

    //criteria.add(Restrictions.ilike("merchantSubUrl", enterdUrl));

    merDetails=(MerchnatDetails) criteria.uniqueResult();
    }catch(Exception e){
        e.printStackTrace();
    }


        System.out.println(merDetails.getMerchantId());
        return merDetails;
    }

这是控制台中显示的错误：

java.lang.NullPointerException
    at com.its.ecommerce.dao.UrlDaoImpl.getMerchantByUrl(UrlDaoImpl.java:37)
    at com.its.ecommerce.service.UrlServiceImpl.getCorrespodingUrl(UrlServiceImpl.java:34)
    at com.its.ecommerce.controller.AuthenticationFilter.doFilter(AuthenticationFilter.java:44)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

我的Web.xml文件如下所示：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>EcomUrl</display-name>
    <!-- The definition of the Root Spring Container shared by all Servlets 
        and Filters -->
        <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.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>
    <filter>
        <filter-name>AuthenticationFilter</filter-name>
        <filter-class>com.its.ecommerce.controller.AuthenticationFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>AuthenticationFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

   <filter>
        <filter-name>charsetFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <init-param>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <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/applicationContext.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>

    <session-config>
        <session-timeout>25</session-timeout>
    </session-config>
  <welcome-file-list> 
    <welcome-file>index.jsp</welcome-file>
   </welcome-file-list>
</web-app>

应用程序上下文：

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns:beans="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:jdbc="http://www.springframework.org/schema/jdbc"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
              http://www.springframework.org/schema/beans/spring-beans-4.1.xsd 
              http://www.springframework.org/schema/jdbc 
              http://www.springframework.org/schema/jdbc/spring-jdbc-4.1.xsd
              http://www.springframework.org/schema/tx 
              http://www.springframework.org/schema/tx/spring-tx-4.1.xsd
              http://www.springframework.org/schema/context
              http://www.springframework.org/schema/context/spring-context-4.1.xsd
              http://www.springframework.org/schema/mvc
              http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
    <context:property-placeholder location="classpath:application.properties"/>
    <context:component-scan base-package="com.its.ecommerce.*"/>
    <context:annotation-config/>
    <context:spring-configured/>
    <mvc:annotation-driven/>
    <mvc:resources mapping="/resources/**" location="/resources/"/>
    <!-- Data Source Declaration for Hibernate-->
    <beans:bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <beans:property name="driverClassName" value="${jdbc.driverClassName}"/>
        <beans:property name="url" value="${jdbc.url}"/>
        <beans:property name="username" value="${jdbc.username}"/>
        <beans:property name="password" value="${jdbc.password}"/>
    </beans:bean>
    <beans:bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <beans:property name="dataSource" ref="dataSource"></beans:property>
        <beans:property name="packagesToScan" value="com.its.ecommerce.model"/>
        <beans:property name="hibernateProperties">
            <beans:props>
                <beans:prop key="hibernate.dialect">${hibernate.dialect}</beans:prop>
                <!-- <beans:prop key="hibernate.default_schema">dbo</beans:prop>-->
                <beans:prop key="hibernate.c3p0.min_size">${hibernate.minpool}</beans:prop>
                <beans:prop key="hibernate.c3p0.max_size">${hibernate.maxpool}</beans:prop>
                <beans:prop key="hibernate.show_sql">${hibernate.show_sql}</beans:prop>
                <beans:prop key="hibernate.format_sql">${hibernate.format_sql}</beans:prop>      
            </beans:props>
        </beans:property>
    </beans:bean>
    <!-- Enable the configuration of transactional behavior based on annotations -->
    <tx:annotation-driven transaction-manager="transactionManager"/>
    <!-- Transaction Manager is defined -->
    <beans:bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <beans:property name="sessionFactory" ref="sessionFactory"/>
    </beans:bean> 
    <beans:bean id="jspViewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <beans:property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
        <beans:property name="prefix" value="/WEB-INF/view/"/>
        <beans:property name="suffix" value=".jsp"/>
    </beans:bean>
</beans:beans>

${hibernate.dial}
${hibernate.minpool}
${hibernate.maxpool}
${hibernate.show_sql}
${hibernate.format_sql}

您的筛选器不受spring管理，因此dao不可用于自动连接

---

您应该使用

DelegatingFilterProxy

并将过滤器声明为spring组件

能否向我们展示一下applicationContext.xml中的配置

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns:beans="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:jdbc="http://www.springframework.org/schema/jdbc"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
              http://www.springframework.org/schema/beans/spring-beans-4.1.xsd 
              http://www.springframework.org/schema/jdbc 
              http://www.springframework.org/schema/jdbc/spring-jdbc-4.1.xsd
              http://www.springframework.org/schema/tx 
              http://www.springframework.org/schema/tx/spring-tx-4.1.xsd
              http://www.springframework.org/schema/context
              http://www.springframework.org/schema/context/spring-context-4.1.xsd
              http://www.springframework.org/schema/mvc
              http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
    <context:property-placeholder location="classpath:application.properties"/>
    <context:component-scan base-package="com.its.ecommerce.*"/>
    <context:annotation-config/>
    <context:spring-configured/>
    <mvc:annotation-driven/>
    <mvc:resources mapping="/resources/**" location="/resources/"/>
    <!-- Data Source Declaration for Hibernate-->
    <beans:bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <beans:property name="driverClassName" value="${jdbc.driverClassName}"/>
        <beans:property name="url" value="${jdbc.url}"/>
        <beans:property name="username" value="${jdbc.username}"/>
        <beans:property name="password" value="${jdbc.password}"/>
    </beans:bean>
    <beans:bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <beans:property name="dataSource" ref="dataSource"></beans:property>
        <beans:property name="packagesToScan" value="com.its.ecommerce.model"/>
        <beans:property name="hibernateProperties">
            <beans:props>
                <beans:prop key="hibernate.dialect">${hibernate.dialect}</beans:prop>
                <!-- <beans:prop key="hibernate.default_schema">dbo</beans:prop>-->
                <beans:prop key="hibernate.c3p0.min_size">${hibernate.minpool}</beans:prop>
                <beans:prop key="hibernate.c3p0.max_size">${hibernate.maxpool}</beans:prop>
                <beans:prop key="hibernate.show_sql">${hibernate.show_sql}</beans:prop>
                <beans:prop key="hibernate.format_sql">${hibernate.format_sql}</beans:prop>      
            </beans:props>
        </beans:property>
    </beans:bean>
    <!-- Enable the configuration of transactional behavior based on annotations -->
    <tx:annotation-driven transaction-manager="transactionManager"/>
    <!-- Transaction Manager is defined -->
    <beans:bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <beans:property name="sessionFactory" ref="sessionFactory"/>
    </beans:bean> 
    <beans:bean id="jspViewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <beans:property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
        <beans:property name="prefix" value="/WEB-INF/view/"/>
        <beans:property name="suffix" value=".jsp"/>
    </beans:bean>
</beans:beans>