Question

我尝试使用spring和thymeleaf创建简单的形式。这是我的代码：

@GetMapping("users/{id}")
public String editUser(@PathVariable long id,  Model model)
{
    User user = userService.findByID(id);
    Iterable<Role> roles= roleService.findAll();
    UserEditForm userEditForm = new UserEditForm(user);
    model.addAttribute("userEditForm", userEditForm);
    model.addAttribute("allRoles", roles);
    return "admin/userEdit";
}

@PostMapping("users/{id}")
public String updateUser(@PathVariable long id, @ModelAttribute UserEditForm userEditForm,
                         BindingResult bindingResult)
{
    userEditValidator.validate(userEditForm, bindingResult);

    if (bindingResult.hasErrors()) {
        return "admin/userEdit";
    }

    User user = new User(userEditForm);
    userService.save(user);
    return "redirect:/admin/users/{id}";
}

几乎所有事情都按照预期行事。当形式上有错误时，我唯一不理解的是缺少allRoles modelAttribute（列表为空）（我会重定向回来纠正它们）。我认为可能会重置模型对象，但userEditForm与Get请求中的相同。我错过了什么吗？如果不是我怎么能纠正它？不确定再次从db获取角色是个好主意。

编辑：

根据评论的建议，我想出了类似的东西（效果很好）：

@GetMapping("users/{id}")
public String editUser(@PathVariable long id,  Model model, HttpSession session)
{
    User user = userService.findByID(id);
    Iterable<Role> roles= roleService.findAll();
    UserEditForm userEditForm = new UserEditForm(user);
    model.addAttribute("userEditForm", userEditForm);
    model.addAttribute("allRoles", roles);
    session.setAttribute("allRoles", roles);
    return "admin/userEdit";
}

@PostMapping("users/{id}")
public String updateUser(@PathVariable long id, @ModelAttribute UserEditForm userEditForm,
                         BindingResult bindingResult, @SessionAttribute("allRoles") Iterable<Role> roles,
                         Model model, SessionStatus sessionStatus)
{
    userEditValidator.validate(userEditForm, bindingResult);


    if (bindingResult.hasErrors()) {
        model.addAttribute("allRoles", roles);
        return "admin/userEdit";
    }

    User user = new User(userEditForm);
    userService.save(user);
    sessionStatus.setComplete();
    return "redirect:/admin/users";
}

现在刚收到一些问题。这是最好的方法吗？或者我应该在需要时查询数据库＆＃34;角色＆＃34;？或者也许是一些不同的方法 2. UserEditForm对象如何得到＆＃34;自动注入＆＃34;到模型（我可以在视图中使用它），而我需要在model.addAttribute()方法中使用roles调用updateUser？

Answer 1

根据评论的建议，我想出了类似的东西（效果很好）：

@GetMapping("users/{id}")
public String editUser(@PathVariable long id,  Model model, HttpSession session)
{
    User user = userService.findByID(id);
    Iterable<Role> roles= roleService.findAll();
    UserEditForm userEditForm = new UserEditForm(user);
    model.addAttribute("userEditForm", userEditForm);
    model.addAttribute("allRoles", roles);
    session.setAttribute("allRoles", roles);
    return "admin/userEdit";
}

@PostMapping("users/{id}")
public String updateUser(@PathVariable long id, @ModelAttribute UserEditForm userEditForm,
                         BindingResult bindingResult, @SessionAttribute("allRoles") Iterable<Role> roles,
                         Model model, SessionStatus sessionStatus)
{
    userEditValidator.validate(userEditForm, bindingResult);


    if (bindingResult.hasErrors()) {
        model.addAttribute("allRoles", roles);
        return "admin/userEdit";
    }

    User user = new User(userEditForm);
    userService.save(user);
    sessionStatus.setComplete();
    return "redirect:/admin/users";
}

模型属性＆＃34;迷路＆＃34;在春天

1 个答案: