[英]autowire by name not working spring MVC
web.xml
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>spring-mvc</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
我的spring-mvc-servlet.xml
<context:component-scan base-package="org.app.controller" />
<mvc:resources mapping="/resources/**" location="/WEB-INF/resources/" />
<mvc:annotation-driven />
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix">
<value>/WEB-INF/pages/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean>
我的控制器:僅供參考
@Controller
public class HomeController {
LoginService loginService;
@RequestMapping(value = "/", method = RequestMethod.GET)
public String login(Model model) {
loginService.checkLoginDetails(new LoginDetails("Svn", 1));
return "login";
}
AppplicationContext.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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx" 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/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd">
<!-- <context:annotation-config /> -->
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
<property name="url" value="jdbc:mysql://localhost:3306/test"></property>
<property name="username" value="root"></property>
<property name="password" value=""></property>
</bean>
<bean class="org.app.controller.HomeController" autowire="byName"></bean>
<bean id="loginDAO" class="org.app.DAOImpl.LoginDAOImpl" autowire="byName"></bean>
<bean id="loginService" class="org.app.DAOServiceImpl.LoginServiceImpl" autowire="byName"></bean>
<bean id="employeeDAO" class="org.app.DAOImpl.EmployeeDAOImpl" autowire="byName"></bean>
<bean id="employeeService" class="org.app.DAOServiceImpl.EmployeeDAOServiceImpl" autowire="byName"></bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="annotatedClasses">
<list>
<value>org.app.entity.Employee</value>
<value>org.app.entity.LoginDetails</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
<prop key="hibernate.hbm2ddl.auto">create</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
<!-- <context:component-scan base-package="org.infy"> <context:exclude-filter
expression="org.springframework.stereotype.Controller" type="annotation"
/> </context:component-scan> -->
<tx:annotation-driven />
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
</beans>
LoginServiceImpl
public class LoginServiceImpl implements LoginService{
LoginDAO loginDAO;
@Override
@Transactional
public boolean checkLoginDetails(LoginDetails loginDetails) {
return loginDAO.checkLoginDetails(loginDetails);
}
}
問題 :我的LoginDAO為空。 Spring在沒有注釋的情況下無法使用自動裝配實例化其對象,但是,當我將其與注釋以及ApplicationContext.xml中的適當更改一起使用時,Spring可以正常工作。
我的LoginService bean正在由調度程序servlet上下文的組件掃描實例化。 現在,當實例化LoginServiceImpl時,spring應該查看RootApplication上下文中的其他bean定義,但事實並非如此。 我不明白為什么在將@autowire用於或啟用組件掃描時會發生這種情況。 它正常工作,然后為什么不沒有注釋。
我也不確定我要做什么。 我在玩Spring MVC並陷入困境。
在AppplicationContext.xml中,您需要為bean指定注入的依賴項作為元素
請更新您的ApplicationContext.xml
<bean id="loginService" class="org.app.DAOServiceImpl.LoginServiceImpl" autowire="byName">
<property name="loginDAO" ref="loginDAO"> </property>
</bean>
EmployeeService和您的控制器也一樣。
<bean class="org.app.controller.HomeController" autowire="byName">
<property name="loginService" ref="loginService"> </property>
</bean>
<bean id="employeeService" class="org.app.DAOServiceImpl.EmployeeDAOServiceImpl" autowire="byName">
<property name="employeeDAO" ref="employeeDAO"> </property>
</bean>
盡管我仍然建議您使用注釋。
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