关于SpringMVC请求域对象的数据共享问题

<a th:href="@{/test/1}">传了参数</a>
@RequestMapping("/test/{id}")
public String test(@PathVariable("id")Integer id){
    System.out.println(id);
    return "index";
}

@RequestMapping("/testParam")
public String Param(HttpServletRequest request){
    String userName = request.getParameter("userName");
    String password = request.getParameter("password");
    return "index";
}

<a th:href="@{/testParam(username='admin',password='123')}">传了参数</a>
@RequestMapping("/testParam")
public String testParam(String username,String password){
    System.out.println("username:"+username+",password:"+password);
    return "index";
}

@RequestMapping("/testPojo")
public String testPojo(User user){
    System.out.println(user);
    return "index";
}

<filter>
    <filter-name>CharacterEncodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <!--设置字符集-->
    <init-param>
        <param-name>encoding</param-name>
        <param-value>UTF-8</param-value>
    </init-param>
    <!--强制响应字符集-->
    <init-param>
        <param-name>forceResponseEncoding</param-name>
        <param-value>true</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>CharacterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

@RequestMapping("/test")
public String test(HttpServletRequest request){
    request.setAttribute("hello","hello");
    return "index";
}

//使用ModelAndView对象的方式
@RequestMapping("/")
public ModelAndView toIndex(HttpServletRequest request){
    ModelAndView mav = new ModelAndView();
    //设置共享数据
    mav.addObject("result","mavResult");
    //设置视图名称
    //视图名称=逻辑视图名称。
    mav.setViewName("index");
    return mav;
}

//使用Model对象的方式
@RequestMapping("/")
public String toIndexModel(Model model){
    //设置共享数据
    model.addAttribute("result","ModelResult");
    return "index";
}

//使用Map对象的方式
@RequestMapping("/")
public String toIndexModel(Map<String,Object> map){
    //设置共享数据
    map.put("result","MapResult");
    return "index";
}

//使用ModelMap对象的方式
@RequestMapping("/")
public String toIndexModel(ModelMap modelMap){
    //设置共享数据
    modelMap.addAttribute("result","ModelMapResult");
    return "index";
}