Springmvc工程跳转controller无效的解决

 <!-- 自动扫描包，实现支持注解的IOC -->
<context:component-scan base-package="com.bj58.automation.controller" />  //路径基于实际需求添加

 <servlet-mapping>
   <servlet-name>springmvc</servlet-name>
    <url-pattern>*.do</url-pattern>
  </servlet-mapping>

<servlet-mapping>
   <servlet-name>springmvc</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

@Controller
@RequestMapping("/task")
public class TaskController {
    @Autowired
    InsertTask insertTask;//注入添加任务接口
    @RequestMapping(value="/insertTask")
    public void insertTask(@RequestParam("productId") int productId,@RequestParam("taskname") String taskname,
            HttpServletRequest request,Model model) {
        insertTask.insertTaskService(productId, taskname);
    }
    @ResponseBody
    @RequestMapping(value="/demo",method=RequestMethod.GET)
    public String name() {
        System.err.println("demo123");
        return "demo";      
    }

  <mvc:annotation-driven />

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

@Controller
public class ItemController {
    @Autowired
    private ItemService itemService;
    @RequestMapping("/item/{itemId}")
    @ResponseBody
    public TbItem getItemById(@PathVariable Long itemId) {
        System.err.println(123);
        TbItem tbItem = itemService.getItemById(itemId);
        return tbItem;
    }
}

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

<!-- springmvc的前端控制器 -->
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!-- contextConfigLocation不是必须的， 如果不配置contextConfigLocation， springmvc的配置文件默认在：WEB-INF/servlet的name+"-servlet.xml" -->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring/springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>