Question

我正在尝试在Spring MVC应用程序中自动连接服务，但它总是失败！尝试了Internet上每个问题的所有内容，但我找不到答案。问题在于，Spring实际上无法自动连接字段，并说没有这种bean，

尝试了所有操作，更改了代码，配置等。也许现在我项目中的所有内容都太混乱了，我找不到错误了。

@Controller
public class ViewController {

    @Autowired
    private IUserService userService;


    public void setUserService(IUserService userService) {
        this.userService = userService;
    }
}

@Component
@Service("userService")
public class UserServiceImpl implements IUserService {

    private static final SessionFactory sessionFactory = new Configuration().configure("hibernate.cfg.xml").
            addAnnotatedClass(User.class).addAnnotatedClass(Restaurant.class).
            buildSessionFactory();

    public UserServiceImpl() {
    }
}

dispatcher-servlet.xml

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

    <!-- Step 3: Add support for component scanning -->
    <context:component-scan base-package="com.springmvcdemo.Controller" />

    <!-- Step 4: Add support for conversion, formatting and validation support -->
    <mvc:annotation-driven/>

    <!-- Step 5: Define Spring MVC view resolver -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/view/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

    <display-name>spring-mvc-demo</display-name>

    <absolute-ordering />
    <!-- Step 1: Configure Spring MVC Dispatcher Servlet -->
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/dispatcher-servlet.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml</param-value>
    </context-param>
    <!-- Step 2: Set up URL mapping for Spring MVC Dispatcher Servlet -->
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <context:annotation-config />
    <context:component-scan base-package="com.springmvcdemo.Services" />
</beans>

Error creating bean with name 'viewController': Unsatisfied dependency expressed through field 'userService'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.springmvcdemo.Services.IUserService' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

Answer 1

问题是SessionFactory是在服务的静态字段中构造的。

可以找到该类，但是创建会话工厂时出现了一些错误，这就是为什么错误消息中包含“实例化bean失败”的原因。

移动要由Spring管理的会话工厂，然后注入它是解决方法。

没有看到使用Autowired注释的bean，没有任何帮助

1 个答案: