跳轉

常用兩種方法

1 使用ModelAndView

@RequestMapping(value = {"", "/", "/index"}, method = RequestMethod.GET)
public ModelAndView index(ModelAndView mv, Object obj) {
    mv.addObject("obj", obj);
    mv.setViewName("/index"); 
    return mv; 
}

2 直接返回String

@RequestMapping(value = {"", "/", "/index"}, method = RequestMethod.GET)
 
public String index(Model model, Object obj) {
    model.addAttribute("obj", obj);
    return "/index"; 
}

重定向

1 使用ModelAndView

return new ModelAndView("redirect:/index");

2 直接返回String

return "redirect:/index";

重定向傳參

1 直接拼接到url後面，頁面或controller直接取這個msg引數，但這種方法相當於位址列傳參，有可能對中文解碼不正確出現亂碼

return new ModelAndView("/index?msg=xxxxx");

return "redirect:/index?msg=xxxx";

@RequestMapping(value = {"", "/", "/index"}, method = RequestMethod.GET)
public ModelAndView index(ModelAndView mv, RedirectAttributes redirectAttributes, Object obj) {
    redirectAttributes.addAttribute("obj", obj);
    mv.setViewName("redirect:/index"); 
    return
 
 mv; 
}

@RequestMapping(value = {"", "/", "/index"}, method = RequestMethod.GET)
public String index(RedirectAttributes redirectAttributes, Object obj) {
    redirectAttributes.addAttribute("obj", obj);
    return "redirect:/index"; 
}

2 不拼接url引數，使用RedirectAttributes進行引數的存取

@RequestMapping(value = {"", "/", "/index"}, method = RequestMethod.GET)
public ModelAndView index(ModelAndView mv, RedirectAttributes redirectAttributes, Object obj) {
    redirectAttributes.addFlashAttribute("obj", obj);
    mv.setViewName("redirect:/index"); 
    return mv; 
}

@RequestMapping(value = {"", "/", "/index"}, method = RequestMethod.GET)
public String index(RedirectAttributes redirectAttributes, Object obj) {
    redirectAttributes.addFlashAttribute("obj", obj);
    return "redirect:/index"; 
}

取引數obj的時候，如果是頁面，可以直接表示式讀取。

但此值只能使用一次，重新整理頁面就沒了。原理是把這個值放到session中，在跳轉後馬上移除物件。所以重新整理頁面後就沒了

也可以直接接收HttpServletRequest，HttpServletResponse

@RequestMapping(value = "/index", method = RequestMethod.GET)  
public ModelAndView saveUser(HttpServletRequest request, HttpServletResponse response, UserModel user) throws Exception {  
    ModelAndView mv = new ModelAndView("/user/save/result");//預設為forward模式  
//  ModelAndView mv = new ModelAndView("redirect:/user/save/result");//redirect模式  
    mv.addObject("message","儲存使用者成功！");  
    return mv;  
}