@RequestMapping("/testServletAPI")
public String testServletAPI(HttpServletRequest request) {
    request.setAttribute("key","value");
    return "index";
}

@RequestMapping("/testModelAndView")
public ModelAndView testModelAndView(){
    ModelAndView mv = new ModelAndView();
    // 向請求域中共享數(shù)據(jù)
    mv.addObject("key","value");
    // 設(shè)置視圖，實(shí)現(xiàn)跳轉(zhuǎn)
    mv.setViewName("index");
    return mv;
}

@RequestMapping("/testModel")
public String testModel(Model model) {
    model.addAttribute("key","value");
    return "index";
}

@RequestMapping("/testMap")
public String testMap(Map<String,Object> map) {
    map.put("key","value");
    return "index";
}

@RequestMapping("/testModelMap")
public String testModelMap(ModelMap modelMap) {
    modelMap.addAttribute("key","value");
    return "index";
}

//DispatcherServlet源碼，將數(shù)據(jù)封裝的部分代碼
// Actually invoke the handler.
mv = ha.handle(processedRequest, response, mappedHandler.getHandler());

@RequestMapping("/testSession")
public String testSession(HttpSession session){
    session.setAttribute("key","value");
    return "index";
}

@RequestMapping("testApplication")
public String testApplication(HttpSession session){
    ServletContext servletContext = session.getServletContext();
    servletContext.setAttribute("key","value");
    return "index";
}