controller代码：
@Controller
public class UserController {
@Autowired
private UserService userService;
@RequestMapping(value = "/add.action")
public String add(Model model) throws Exception {
userService.add();
System.out.println("controller............");
return "/WEB-INF/jsp/1.jsp";
}
}
service代码
public class UserService {
@Autowired
private UserDaoImpl userDao;
public void add() throws Exception {
userDao.add();
System.out.println("service..............");
}
}
dao代码
@Repository
public class UserDaoImpl{
public void add() throws Exception {
System.out.println("daoImpl..............");
}
}
spring配置文件：
<?xml version="1.0" encoding="UTF-8"?>
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:component-scan base-package="cn.taxas.spring.dao"/>-->
<bean id="userDao" class="cn.taxas.spring.dao.UserDaoImpl"/>
<bean id="userService" class="cn.taxas.spring.service.UserService"/>
springmvc配置文件；
<?xml version="1.0" encoding="UTF-8"?>
xmlns:mvc="http://www.springframework.org/schema/mvc"
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/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">
<mvc:annotation-driven/>
<context:component-scan base-package="cn.taxas.spring.controller">
<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<!--<bean id="userController" class="cn.taxas.spring.controller.UserController"/>-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"/>
报错：
java.lang.NullPointerException
at cn.taxas.spring.service.UserService.add(UserService.java:20)
at cn.taxas.spring.controller.UserController.add(UserController.java:23)
at sun.reflect.GeneratedMethodAccessor42.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
