处理错误ASP.NET Web API

Question

我正在创建一个ASP.NET Web API方法。 Web方法接受用于查询Oracle数据库的四个输入参数，并以JSON返回结果。 输入参数的类型为字符串和日期时间。 API调用类似于?id=123&date_in=01-JAN-16 。 在控制器中，我必须处理验证错误，例如API调用中的id为null或日期格式不同于dd-MMM-yy，并返回适当的错误消息。

public class DataController : ApiController
{
    [HttpGet]
    public HttpResponseMessage Getdetails(string id,DateTime date_in)
        {
            List<OracleParameter> prms = new List<OracleParameter>();
            prms.Add(new OracleParameter("id", OracleDbType.Varchar2, id, ParameterDirection.Input));
            prms.Add(new OracleParameter("date_in", OracleDbType.Date, date_in, ParameterDirection.Input));
           string connStr = ConfigurationManager.ConnectionStrings["DtConnection"].ConnectionString;
        using (OracleConnection dbconn = new OracleConnection(connStr))
        {
            DataSet userDataset = new DataSet();
            var strQuery = "SELECT * from SAMPLE where id = :id and date_in = :date_in ";
            var returnObject = new { data = new OracleDataTableJsonResponse(connStr, strQuery, prms.ToArray()) };
            var response = Request.CreateResponse(HttpStatusCode.OK, returnObject, MediaTypeHeaderValue.Parse("application/json"));
            ContentDispositionHeaderValue contentDisposition = null;
            if (ContentDispositionHeaderValue.TryParse("inline; filename=TGSData.json", out contentDisposition))
            {
                response.Content.Headers.ContentDisposition = contentDisposition;
            }
            return response;

是否应该创建其他类来处理这些异常？ 我应该如何返回答复？

Answer 1

尝试以下代码

public class DataController : ApiController
            {
                [HttpGet]
                public HttpResponseMessage Getdetails(string id,DateTime date_in)
                {
                    if(id==string.Empty || id==null)
                    {
                      return "Id Value Should not Empty or Null";
                    }
                    if(!Regex.IsMatch(date_in, "^(([0-9])|([0-2][0-9])|([3][0-
                    1]))\-(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\-
                    \d{4}$"))
                    {
                      return "Invalid Date Format";
                    }
                    List<OracleParameter> prms = new List<OracleParameter>();
                    prms.Add(new OracleParameter("id", OracleDbType.Varchar2,
                    id, ParameterDirection.Input));
                    prms.Add(new OracleParameter("date_in", OracleDbType.Date, date_in, ParameterDirection.Input));
                       string connStr = ConfigurationManager.ConnectionStrings["DtConnection"].ConnectionString;
                    using (OracleConnection dbconn = new OracleConnection(connStr))
                    {
                        DataSet userDataset = new DataSet();
                        var strQuery = "SELECT * from SAMPLE where id = :id and date_in = :date_in ";
                        var returnObject = new { data = new OracleDataTableJsonResponse(connStr, strQuery, prms.ToArray()) };
                        var response = Request.CreateResponse(HttpStatusCode.OK, returnObject, MediaTypeHeaderValue.Parse("application/json"));
                        ContentDispositionHeaderValue contentDisposition = null;
                        if (ContentDispositionHeaderValue.TryParse("inline; filename=TGSData.json", out contentDisposition))
                        {
                            response.Content.Headers.ContentDisposition = contentDisposition;
                        }
                        return response;
            }
            }

Answer 2

我们可以扩展ExceptionFilterAttribute并创建一个自定义的异常过滤器属性。

public class CustomExceptionFilterAttribute : ExceptionFilterAttribute
{
    public override void OnException(HttpActionExecutedContext context)
    {
        var exception = context.Exception; 
        context.Response = new HttpResponseMessage(System.Net.HttpStatusCode.InternalServerError);
        context.Response.Content = new StringContent(exception.Message);
    }
}

并在ApiController中使用它来返回验证消息。

[HttpGet]
[CustomExceptionFilterAttribute]
public HttpResponseMessage Getdetails(string id, DateTime date_in)
{
        if (string.IsNullOrEmpty(id))
        {
            throw new ArgumentNullException("id");
        }
        //...
}