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Spring MVC CRUD controller best pactice

I am trying to find the best approach for a simple Spring MVC CRUD controller. There are many examples of CRUD controllers both on the Internet and in this forum, but most of them suffer from one of two problems:

  • After saving / updating or deleting, they display a message about saving and updating, but the URL that they click still has "/ update / {id}" or "/ delete / {id}". This is not true because the displayed content is usually a list of objects.

or

  • The controller redirects to the showAll view, but then there is no message that an action has occurred that is not user-friendly.

Does anyone have an example crud controller that doesn't have these two issues?

Thanks,

Henry

@Controller @RequestMapping(value="/role") public class RoleController { private static final Logger log = Logger.getLogger(RoleController.class); @Autowired private RoleValidator validator = null; @Autowired private RoleService service = null; public void setService(RoleService service) { this.service = service; } public void setValidator(RoleValidator validator) { this.validator = validator; } @RequestMapping(method=RequestMethod.GET) public String showForm(ModelMap model){ List<Role> domainObjectList = service.getRoles(); model.addAttribute("domainObjectList", domainObjectList); return "role"; } @RequestMapping(value="/add", method=RequestMethod.GET) public String preAdd(ModelMap model){ Role domainObject = new Role(); model.addAttribute("domainObject", domainObject); addConstrainedFields(model); return "roleEdit"; } @RequestMapping(value="/add", method=RequestMethod.POST) public ModelAndView add(@ModelAttribute(value="domainObject") Role domainObject, BindingResult result) { validator.validate(domainObject, result); ModelAndView mv = new ModelAndView("role"); if(result.hasErrors()){ mv = new ModelAndView("roleEdit"); mv.addObject("domainObject", domainObject); return mv; } service.insertRole( domainObject ); mv.addObject("domainObjectList", service.getRoles()); mv.addObject("messageKey","label.form.item.added"); //PROBLEM: the URL will remain "/add", but the content will be one of showing all roles + message that role was added. return mv; } @RequestMapping(value="/update/{id}") public String preUpdate(@PathVariable Integer id, ModelMap model) { Role domainObject = service.getRole( id ); model.addAttribute("domainObject", domainObject); return "roleEdit"; } @RequestMapping(value="/update", method=RequestMethod.POST) public String update(@ModelAttribute(value="domainObject") Role domainObject, ModelMap model, BindingResult result){ validator.validate(domainObject, result); ModelAndView mv = new ModelAndView("role"); if(result.hasErrors()){ model.addAttribute("domainObject", domainObject); return "roleEdit"; } service.insertRole(domainObject); model.addAttribute("messageKey","label.form.item.added"); model.addAttribute("domainObjectList", service.getRoles()); //PROBLEM: the message that the object was updated will be lost, but the URL will be /role and we will show all roles. return "redirect:/role"; } @RequestMapping(value="/delete/{id}") public String delete(@PathVariable Integer id, ModelMap model) { Role domainObject = service.getRole( id ); if (domainObject == null) { model.addAttribute("messageKey","label.form.item.notfound"); return showForm(model); } service.deleteRole(domainObject); model.addAttribute("messageKey","label.form.item.deleted"); return showForm(model); } @RequestMapping(value="/delete", method=RequestMethod.POST) public ModelAndView delete(@ModelAttribute(value="domainObject") Role domainObject, BindingResult result){ validator.validate(domainObject, result); ModelAndView mv = new ModelAndView("role"); if(!result.hasErrors()){ service.deleteRole(domainObject); mv.addObject("messageKey","label.form.item.deleted"); domainObject = new Role(); mv.addObject("domainObject", domainObject); } mv.addObject("domainObjectList", service.getRoles()); return mv; } }
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1 answer

  • You should use a RESTful URL and use gEt for rEad, posT for creaTe, pUt for update, and Delete to Delete. Use HiddenHttpMethodFilter for user agents that are not PUT or DELETE.

  • Use the Post-Redirect-Get pattern to avoid repeated POSTs.

  • Use Flash Attributes to display success / failure messages on subsequent pages.

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Source: https://habr.com/ru/post/950552/

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