java Spring - 将 BindingResult 添加到新创建的模型属性
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Spring - adding BindingResult to newly created model attribute
提问by bezmax
My task is - to create a model attribute by given request parameters, to validate it (in same method) and to give it whole to the View.
我的任务是 - 通过给定的请求参数创建模型属性，对其进行验证（以相同的方法）并将其完整地提供给视图。
I was given this example code:
我得到了这个示例代码：
@Controller
class PromotionController {
@RequestMapping("promo")
public String showPromotion(@RequestParam String someRequestParam, Model model) {
//Create the model attribute by request parameters
Promotion promotion = Promotions.get(someRequestParam);
//Add the attribute to the model
model.addAttribute("promotion", promotion);
if (!promotion.validate()) {
BindingResult errors = new BeanPropertyBindingResult(promotion, "promotion");
errors.reject("promotion.invalid");
//TODO: This is the part I don't like
model.put(BindingResult.MODEL_KEY_PREFIX + "promotion", errors);
}
return
}
}
This thing sure works, but that part with creating key with MODEL_KEY_PREFIX and attribute name looks very hackish and not a Spring style to me. Is there a way to make the same thing prettier?
这东西确实有效，但是使用 MODEL_KEY_PREFIX 和属性名称创建密钥的那部分看起来很hackish，对我来说不是 Spring 风格。有没有办法让同样的东西更漂亮？
采纳答案by bezmax
Skaffman answered the question but disappeared, so I will answer it for him.
斯卡夫曼回答了问题但消失了，所以我会为他回答。
The binding validation thing is there to bind and validate parameters, not arbitrary business objects.
绑定验证用于绑定和验证参数，而不是任意业务对象。
That means, that if I need to do some custom validation of some general data that was not submitted by the user- I need to add some custom variable to hold that status and not use BindingResult.
这意味着，如果我需要对用户未提交的一些常规数据进行一些自定义验证- 我需要添加一些自定义变量来保持该状态，而不是使用 BindingResult。
This answers all the questions I had with BindingResult, as I thought it had to be used as a container for any kind of errors.
这回答了我对 BindingResult 的所有问题，因为我认为它必须用作任何类型错误的容器。
Again, thanks @Skaffman.
再次感谢@Skaffman。
