配置视图解析器：

        我们在指定视图的时候路径是有重复的，重复的操作可以用视图解析器，让框架帮我们：

        mv.setViewName("/WEB-INF/view/show.jsp");
        mv.setViewName("/WEB-INF/VIEW/other.jsp");

                        ​​​​​​​        

 在springmvc配置文件中：

<?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
       https://www.springframework.org/schema/context/spring-context.xsd">

    <!--声明组件扫描器-->
    <context:component-scan base-package="com.lifang.controller"/>

    <!--声明springmvc框架中的视图解析器，设置视图文件的路径-->
    <bean class = "org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--前缀，视图文件的路径-->
        <property name = "prefix" value = "/WEB-INF/view/"/>
        <!--后缀，视图文件的扩展名-->
        <property name = "suffix" value = ".jsp"/>
    </bean>
</beans>

改进后的代码：

@Controller
public class MyController {
    @RequestMapping(value = {"/some.do","/first.do"}) // value = "/some.do"
    public ModelAndView doSome(){
        ModelAndView mv = new ModelAndView();
        mv.addObject("msg","欢迎使用Springmvc做web开发");
        mv.addObject("fun","执行的是doSome方法");
        //show是视图文件的逻辑名称 (文件名称)
        mv.setViewName("show");
        return mv;
    }
}