Question

你可以帮我解决为什么我不能自动上课？ class UserDaoImpl：

@Repository
public class UserDaoImpl implements UserDao {

    @Autowired
    private SessionFactory sessionFactory;

    @Override
    public void addUser(User user) {
        sessionFactory.getCurrentSession().save(user);
    }

    @Override
    public List<User> getUsers() {
        return sessionFactory.getCurrentSession().createSQLQuery("SELECT * FROM user").list();
    }

}

我希望这个类autowire进入其他类：

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserDao userDao; //here is the error

    @Override
    public void addUser(User user) {

    }

    @Override
    public List<User> getUsers() {
        return null;
    }

}

控制器：

@Controller
public class UserController {

    @Autowired
    UserService userService;

    String message = "This should be a list of users";

    @RequestMapping("/user")
    public ModelAndView showMessage() {
        ModelAndView modelAndView = new ModelAndView("user");
        modelAndView.addObject("message", message);
        return modelAndView;
    }

}

哪里可以出问题？我应该向您展示更多文件吗？谢谢。编辑：好的，这是我的session-factory.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
                <prop key="hibernate.connection.driver_class">org.postgresql.Driver</prop>
                <prop key="hibernate.connection.url">jdbc:postgresql://localhost:8080/****</prop>
                <prop key="hibernate.connection.username">****</prop>
                <prop key="hibernate.connection.password">****</prop>
                <prop key="hibernate.current_session_context_class">thread</prop>
                <prop key="show_sql">true</prop>
            </props>
        </property>
        <property name="annotatedClasses">
            <list>
                <value>model.User</value>
            </list>
        </property>
    </bean>

 </beans>

-class User是简单的POJO，用hibernate映射。也许web.xml可以帮助我们：）

<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
          http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
         version="2.5">

    <display-name>Archetype Created Web Application</display-name>

    <servlet>
        <servlet-name>mvc-dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>mvc-dispatcher</servlet-name>
        <url-pattern>*.htm</url-pattern>
    </servlet-mapping>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/mvc-dispatcher-servlet.xml</param-value>
    </context-param>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

</web-app>

MVC-servlet的dispatcher.xml：

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <context:component-scan base-package="controller" />

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/" />
        <property name="suffix" value=".jsp" />
    </bean>

</beans>

我没有任何applicationContext.xml文件，也许这可能是问题所在，你能帮帮我吗？我正在添加项目和问题的屏幕截图：http://screenshot.cz/75QVH/

Answer 1

@Repository <context:component-scan base-package="controller" />未被@Service按照您向我们展示的内容进行搜索（扫描）。但我们需要查看每个类的包。 Spring会依赖于您告诉您要查看的@Controller，@Repository，@Component和{{1}}。

了解组件扫描在春天的工作原理。

Answer 2

不要在打印bean之前打印@Autowired。否则，将发现找不到类型的豆类 @Autowired private ProjectRepository projectRepository;

无法自动装配。找不到......类型的豆子

2 个答案: