Question

我在asp.net中写了一个webservice，它只是通过存储过程将值插入到表中。 Webservice是通过Android应用程序访问的。我的服务应该返回TRUE（在插入的情况下）或FALSE（在插入失败的情况下）但它也可能引起看起来很奇怪的错误（例外），普通用户无法理解技术术语，所以如何隐藏这些细节并显示正确的消息（或重定向）。这可能是很多错误，例如Outofrange异常，NullException等。

WebServive：

public GPSWebservice () {

        //Uncomment the following line if using designed components 
        //InitializeComponent(); 
    }

    [WebMethod]
    public bool insertCoordinates(string param) 
    {
        BLL bll = new BLL();
        return bll.InsertCoordinates(param);
    }

}

BLL

public bool InsertCoordinates(string param) 
    {

        String[] parts = param.Split(',');
        sqlCom.CommandText = "InsertCoordinates";
        sqlCom.CommandType = CommandType.StoredProcedure;
        bool result ;

        sqlCom.Parameters.Add("@AddedDateTime", SqlDbType.VarChar).Value = Convert.ToDateTime(parts[0].ToString());
        sqlCom.Parameters.Add("@IMEI", SqlDbType.VarChar).Value = parts[1].ToString();
        sqlCom.Parameters.Add("@RecordedDateTime", SqlDbType.VarChar).Value = Convert.ToDateTime(parts[2].ToString());
        sqlCom.Parameters.Add("@Latitude", SqlDbType.VarChar).Value = parts[3].ToString(); ;
        sqlCom.Parameters.Add("@Longitude", SqlDbType.VarChar).Value = parts[4].ToString(); ;
        sqlCom.Parameters.Add("@IsParking ", SqlDbType.Bit).Value = ((parts[5].ToString().Trim()).Equals("0")) ? false : true;
        SqlParameter sqlParam = new SqlParameter("@result", SqlDbType.Int);
        sqlCom.Parameters.Add(sqlParam);
        sqlCom.Parameters["@result"].Direction = ParameterDirection.Output;

        try
        {
            sqlCon.Open();
            sqlCom.ExecuteNonQuery();
            return result = Convert.ToBoolean(sqlParam.Value);
        }



        catch (Exception ex)
        {

            return false; 

        }

        finally 
        {
            sqlCon.Close();
        }

    }
}

SP：

ALTER PROCEDURE [dbo].[InsertCoordinates]

    @AddedDateTime varchar(50),
    @IMEI varchar(50),
    @RecordedDateTime varchar(50),
    @Latitude varchar(50),
    @Longitude varchar(50),
    @IsParking bit,
    @result int output
AS

BEGIN

    SET NOCOUNT ON;
   Begin Try

    If Not exists(select IMEI from dbo.Coordinates where IMEI =@IMEI AND Latitude=@Latitude AND @Longitude=@Longitude)
    Begin
        insert into dbo.Coordinates 
        values (@AddedDateTime, @IMEI, @RecordedDateTime, @Latitude, @Longitude, @IsParking) 

        Set @result = @@ROWCOUNT

        IF(@result = 1)
         Select @result
        Else
         Set @result=0
         Select @result
    End

    Else
    Begin
         Set @result=0
         Select @result
    End
   End Try

   Begin Catch
        Set @result=0
   End Catch

END

Answer 1

取决于。

您可以捕获特定类型的异常并将其“翻译”为人类可读的内容。

try
{
     // do stuff
}
catch (OracleException ex)
{
    if (ex.Code == 15) throw new MyApplicationException("Something your users might make sense of", ex); // Code==15 is made-up
}
// Catch more specific errors where you know what happened and can give meaningful information to the user
catch (Exception ex)
{
    throw new MyApplicationException("General error message: Something went horribly wrong", ex);
}

替代方法是不返回布尔值，而是返回自定义类型：

public class ServiceResult
{
    public bool Success { get; set; }
    public string Message { get; set; }
}

public ServiceResult InsertCoordinates(string param) 
{
    // ... code

    try
    {
        sqlCon.Open();
        sqlCom.ExecuteNonQuery();
        return new ServiceResult() { Success = True };
    }
    catch (Exception ex)
    {
        return new ServiceResult() { Success = False, Message = "Crash & Burn!" }; 
    }
    // ... more code
}

哪个更好取决于您的体系结构以及您希望如何使用服务的结果。

Answer 2

你可以这样做：

public enum ErrorCode
{
   NoError,
   DatabaseError,
   UnknownError,
   OutofrangeError
}
[WebMethod]
public ErrorCodes insertCoordinates(string param) 
{
    ErrorCodes result = ErrorCodes.NoError;
    try
    {
        BLL bll = new BLL();
        bool dbResult = bll.InsertCoordinates(param);
        if (!dbResult) {result = ErrorCodes.DatabaseError;}
    }
    catch (OutOfRangeException ex) {result = ErrorCodes.OutofrangeError;}
    catch (Exception ex) {result = ErrorCodes.UnknownError;}
    return result;
}

隐藏异常并打印体面的消息

2 个答案: