The return value of the JAVA framework springmvc controller

1. Return value: ModelView object.

Use modelAndView.setViewName to set the returned page. Use modelAndView.addObject to set the returned data.

1     @RequestMapping("/edit")
2     public ModelAndView editTable(HttpServletRequest request){
3         ModelAndView modelAndView=new ModelAndView();
4         String id=request.getParameter("id");
5         goods goodser= this.goodsService.findByIdSer(Integer.parseInt(id));
6         modelAndView.setViewName("edit");
7         modelAndView.addObject("goods",goodser);
8         returnmodelAndView;
9      }

 Second, the return value: string

String is the page name stripped of extensions

1     @RequestMapping("/edit")
2     public String editTable(HttpServletRequest request,Model model){
3         String id=request.getParameter("id");
4         goods goodser= this.goodsService.findByIdSer(Integer.parseInt(id));
5         model.addAttribute("goods",goodser);
6         return "edit";
7     }

3. Return value: void

Determine the set return value through the parameter httpservletrequest, set the value and forward through the request.

1     @RequestMapping("/edit")
2     public void editTable(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
3         String id=request.getParameter("id");
4         goods goodser= this.goodsService.findByIdSer(Integer.parseInt(id));
5         request.setAttribute("gooods",goodser);
6         request.getRequestDispatcher("WEB-INF/jsp/success.jsp").forward(request,response);
7     }

 Four: forwarding

Forward through return forward:*.action, and set data through Model. Absolute paths are those with /

1     @RequestMapping("/update")
2     public String upddateById(goods goods,Model model){
3         this.goodsService.updateById(goods);
4         model.addAttribute("id",goods.getId());
5     return  "forward:edit.action";
6     }

Absolute path writing: Absolute paths and relative paths are applied according to requirements.

 

1    @RequestMapping("/update")
2     public String upddateById(goods goods,Model model){
3         this.goodsService.updateById(goods);
4         model.addAttribute("id",goods.getId());
5     return  "redirect:/goods/edit.action";
6     }

 

 

 

Note that you need to bring the extension .action here

The url has not changed.

5. Redirect:

Set the data through the Model by returning " redirect :*.action"  . Absolute paths are those with /.

1     @RequestMapping("/update")
2     public String upddateById(goods goods,Model model){
3         this.goodsService.updateById(goods);
4         model.addAttribute("id",goods.getId());
5     return  "redirect:edit.action";
6     }

 url changed.

The bottom layer of Model also sets attributes through request.setAttribute, but better encapsulates the request, and the value can be set whether it is forwarding or redirecting.