AspectJ导致sessionfactory为null？

Question

每当我在spring-hibernate项目中使用aspect并放入@EnableJAutoproxy时，sessionfactory为null。否则，外翻工作正常。

我用sessionfactory获取空指针异常。只要我删除它，应用程序就可以工作，但Aspect不起作用。

请帮帮我!!!!

    @Aspect
    @Component
    public class AspectHandler {

        @Pointcut("within(com.x.y..*)")
        private void selectAll() {
        }

        @Before("selectAll()")
        public void beforeAdvice() throws Throwable {
            System.out.println("before method exceution");
        }


        @Around("selectAll()")
        public void aroundAdvice(ProceedingJoinPoint joinPoint) throws Throwable{

            System.out.println("firing aspect");
            Object retVal = joinPoint.proceed();
            System.out.println("retval" +retVal);

        }

---

    @Configuration
    @EnableWebMvc
    @EnableTransactionManagement
>   **@EnableAspectJAutoProxy**
    @ComponentScan(basePackages = { "com.x.y.controller","com.x.y.resources.*.controller"})
    public class DispatcherContext extends WebMvcConfigurerAdapter {

        @Bean
        @Autowired
        public HibernateTransactionManager transactionManager(SessionFactory sessionFactory)
        {
            HibernateTransactionManager transactionManager = new HibernateTransactionManager();
            transactionManager.setSessionFactory(sessionFactory);
            return transactionManager;
        }

        @Bean
        public LocalSessionFactoryBean getSessionFactory()throws PropertyVetoException
        {
            LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
            sessionFactory.setDataSource(getDataSource());
            sessionFactory.setHibernateProperties(getHibernateProperties());
            sessionFactory.setPackagesToScan(new String[] { "com.x.y" });
            return sessionFactory;
        }

}

---

StudentDAOImpl

@Repository
public class StudentDAOImpl implements StudentDAO{

    @Autowired
    private SessionFactory sessionFactory;


    @Override
    public Student getStudent(int rollNo) {

        String query = "from Student where rollNo = "+rollNo;
        Session session = sessionFactory.getCurrentSession();
        List<Student> students = session.createQuery(query).list();
        if(students != null && students.size()==1)
        {
            return students.get(0);
        }
        return null;
    }

    @Override
    public List<Student> getStudents() {
        String query = "from Student";
        Session session = sessionFactory.getCurrentSession();
        List<Student> students = session.createQuery(query).list();
        return students;
    }
}   

---

  

StackTrace：

HTTP ERROR 500

Server Error</pre></p><h3>Caused by:</h3><pre>java.lang.NullPointerException
    at com.x.y.resources.school.dao.SchoolDAOImpl.getSchoolDetails(SchoolDAOImpl.java:30)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    at           org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocati        on.java:190)
    at                              org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:      157)
    at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:52)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at      org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedin    gJoinPoint.java:85)
    at com.x.y.config.aop.AspectHandler.aroundAdvice(AspectHandler.java:40)
    at