UserDao is null, I am wiring the bean wrong and need help

Question

My homecontroller has a UserService object that gets wired using spring correctly (it renders the index page just fine using a method no UserService).

Now I setup hibernate, so inside UserService I have a UserDao object that I am trying to wire using spring.

@Service
public class UserServiceImpl implements UserService{

    UserDao userDao;

    public String sayHello() {

        return "hello from user service impl part 2";

    }

    public String getTestUser() {





        return userDao.getById(1L).getUsername();

    }

}

So my HomeController was calling the 'sayHello' method and it was working fine like I said.

@Controller
public class HomeController {

    @Autowired
    private UserService userService;




    @RequestMapping("/")
    public ModelAndView Index() {



        ModelAndView mav = new ModelAndView();

        mav.setViewName("index");
        mav.addObject("message", userService.sayHello());

        mav.addObject("username", userService.getTestUser());
        //userService.getTestUser();

        return mav;
    }

The call to userService.getTestUser() fails, as the UserDao is null.

My app-config.xml is:

<!-- Hibernate SessionFactory -->
    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!--<property name="packagesToScan" value="com.blah.core.db.hibernate"/>  -->
        <property name="configLocation" value="/WEB-INF/classes/hibernate.cfg.xml"/> 
        <property name="hibernateProperties">
            <value>
                hibernate.dialect=org.hibernate.dialect.MySQLDialect
                hibernate.connection.url=jdbc:mysql://localhost/blah
                hibernate.connection.username=dbuser
                hibernate.connection.password=123
                hibernate.query.substitutions=true 'Y', false 'N'
                hibernate.cache.use_query_cache=true
                hibernate.cache.use_second_level_cache=true
                hibernate.cache.provider_class=org.hibernate.cache.EhCacheProvider
                hibernate.jdbc.batch_size=0
            </value>
        </property>
    </bean>

    <!-- Transaction manager for a single Hibernate SessionFactory (alternative to JTA) -->


     <bean id="userDao" class="com.blah.core.db.hibernate.UserDaoImpl">
        <property name="sessionFactory" ref="sessionFactory"/>
    </bean>

Why is my UserDao null? I must be doing something wrong with the wiring?

Also, if I uncomment out the name=packagesToScan line, do I really need to define a bean for each Dao like I did with UserDao? Will the sessionFactory get wired somehow?

Answer 1

Add @AutoWired annotation to userDao.

@Service
public class UserServiceImpl implements UserService{

    @AutoWired
    UserDao userDao;

    ...
}

And make sure you have set up <context:component-scan/> to scan the packages that your @Services and @Controllers are in.

Answer 2

As krock mentioned, your UserDao is not being "wired" properly inside your UserService. Did you even try his suggestion ?