如何使用牛顿软件 json 捕获和处理无效的 json 异常?

Question

我有模型：

public class PushManyRequest
{
[JsonProperty("ids")]
public List<string> Ids { get; set; } 
}

对于我的控制器，我有以下签名：

public async Task<IActionResult> PushMany([FromBody] PushManyRequest request)
{
...
}

如您所见，我正在尝试将请求映射到模型。而且方便易懂！ 我可以添加[Required(ErrorMessage=<message>)]属性，如果没有ids，我将对客户端有自己的错误

但是，如果客户端向我传递了无效的 JSON，该怎么办？例如：

{
"ids": [
"123",
"234"
"235     <---------------------- invalid!!!
]
}

我会为客户回答如下：

{
"status": "error",
"description": [
"Unterminated string. Expected delimiter: ". Path 'ids[991]', line 999, position 1.",
"Unexpected end when deserializing array. Path 'ids[991]', line 999, position 1.",
"Unexpected end when deserializing object. Path 'ids[991]', line 999, position 1."
]
}

如您所见，它非常不友好。这是我的内部解析错误，客户不需要知道它。我想返回类似以下内容：

{
"status": "error",
"description": "Sorry, but your JSON is invalid. Please, check it and try again"
}

但是我不明白我可以在哪里写它以及如何捕捉这种情况。有什么想法吗？谢谢！

Answer 1

你应该研究一下模型状态。

if (!ModelState.IsValid)
{
IEnumerable<ModelError> allErrors = ModelState.Values.SelectMany(v => v.Errors);
foreach (ModelError item in allErrors)
{
orderErrors += item.ErrorMessage;
break;
}
using (var stream = new MemoryStream())
{
var context = (HttpContextBase)Request.Properties["MS_HttpContext"];
context.Request.InputStream.Seek(0, SeekOrigin.Begin);
context.Request.InputStream.CopyTo(stream);
string requestBody = Encoding.UTF8.GetString(stream.ToArray());
log.write_to_log(requestBody, "null", "ModelState is not valid - " + orderErrors); //Saves to your log 
return new HttpResponseMessage((HttpStatusCode)400);
}
}
if (orderErrors != "")
{
return new HttpResponseMessage((HttpStatusCode)400);
}
else 
{
//Something happens
}

这样的事情应该^^