spring-mvc之Spring MVC CRUD Controller 最佳实践

我正在尝试为 Spring MVC 简单 CRUD Controller 找到最佳实践方法。网络上和本论坛上都有很多 CRUD Controller 的示例，但大多数都存在以下两个问题之一:

保存/或更新或删除后，它们会显示保存和更新发生的消息，但它们点击的 URL 上仍然有“/update/{id}”或“/delete/{id}”。这是“错误的”，因为显示的内容通常是对象列表。

或者

Controller 重定向到“showAll” View ，但是没有消息表明发生了操作，这对用户不友好。

有没有人有一个没有这两个问题的 crud Controller 的例子？

谢谢，

亨利

@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; 
    } 
 
} 

请您参考如下方法:

您应该使用 RESTful URL 设计，使用 get 读取，post 来创建，put 到更新，delete 到删除。使用 HiddenHttpMethodFilter对于不 PUT 或 DELETE 的用户代理。

使用 Post-Redirect-Get避免重新发布的模式。

使用 Flash Attributes在后续页面上显示成功/失败消息。