如何将HashMap对象从一个方法传递到同一个Spring MVC控制器类中的另一个方法

Question

I have two services(methods) in a Spring MVC controller class.Now i want to move Map Object from one method to another method with values.

   public class Controller{

   @RequestMapping(value="/reg", method=RequestMethod.POST)
   public ModelAndView loginData(@ModelAttribute("loginBean")LoginBean 
    loginBean,ModelMap model) throws IOException, ParseException
    {
        //Here i have map object with values.
    }

   @RequestMapping(value="/update",method=RequestMethod.POST)
   public ModelAndView updateForm(@ModelAttribute("frontBean")FrontBean 
   frontBean,ModelMap model)
   {
     //here i want to Map Object for update the values
   }
  }

is there any way to do like this please give solution. Thanks in advance

Answer 1

Method 1: Using HttpSession. You can use HttpSession to store your object. See the below example

public class Controller{

   @RequestMapping(value="/reg", method=RequestMethod.POST)
   public ModelAndView loginData(@ModelAttribute("loginBean")LoginBean 
    loginBean,ModelMap model) throws IOException, ParseException
    {
        Map map = new HashMap();
        HttpSession session = req.getSession(false);
        session.setAttribute("myMapObject", map);
    }

   @RequestMapping(value="/update",method=RequestMethod.POST)
   public ModelAndView updateForm(@ModelAttribute("frontBean")FrontBean 
   frontBean,ModelMap model)
   {
     HttpSession session = req.getSession(false);
     session.getAttribute("myMapObject", map);
     session.removeAttribute("myMapObject");
   }
  }

---

Method 2: Using FlashAttribute . It provides a way to store those attributes that are required to be shown on the next page at a redirect on a Post/Redirect/Get.

public class Controller{

   @RequestMapping(value="/reg", method=RequestMethod.POST)
   public ModelAndView loginData(@ModelAttribute("loginBean")LoginBean 
    loginBean,ModelMap model,RedirectAttributes redirectAttrib) throws IOException, ParseException
    {
        Map map = new HashMap();
        redirectAttrib.addAttribute("myMap", map);
        return "redirect:/update";
    }

   @RequestMapping(value="/update",method=RequestMethod.POST)
   public ModelAndView updateForm(@ModelAttribute("frontBean")FrontBean 
   frontBean,@ModelAttribute("myMap")Map myMap,ModelMap model)
   {
  //Use myMap object accordingly.
   }
  }

Answer 2

您可以尝试重定向method.from reg以使用参数进行更新