B4J Question WebApi - Error

Sub SelectFromSql(Query As String, DbType As String) As HttpResponseMessage
    #region Documentation
    ' #Desc1 = Get a category by id
    ' #Desc2 = List all categories
    ' #Elems = 2
    #End region
    Dim List1 As List
    List1.Initialize
    
    Try     
        Dim rs As ResultSet

        ' database type
        If DbType.ToUpperCase = "MSSQL" Then rs = MsSql.ExecQuery2(Query, Null)
        If DbType.ToUpperCase = "MYSQL" Then rs = MySql.ExecQuery2(Query, Null)
        
        ' for all records in returned set
        Do While rs.NextRow
            Dim Map2 As Map
            Map2.Initialize
            For i = 0 To rs.ColumnCount - 1
                Map2.Put(rs.GetColumnName(i), rs.GetString(rs.GetColumnName(i)))
            Next
            ' generiramo list
            List1.Add(Map2)
        Loop
        rs.Close
        
    
        If List1.Size > 0 Then
            Rm.ResponseCode = 200
            Rm.ResponseData = List1
        Else
            Rm.ResponseCode = 404
            Rm.ResponseError = "ERP data for select not found..."
        End If
            
    Catch
        LogError(LastException)
        Rm.ResponseCode = 422
        Rm.ResponseError = "Error Execute Query"
    
    End Try
    
    Return Rm         
End Sub

Public Sub ReturnHttpResponse (mess As HttpResponseMessage, resp As ServletResponse)
    If mess.ResponseCode >= 200 And mess.ResponseCode < 300 Then ' SUCCESS
        If mess.ResponseString = "" Or mess.ResponseString = Null Then mess.ResponseString = "ok"
        If mess.ResponseMessage = "" Then mess.ResponseMessage = "Success"
        mess.ResponseError = Null
    Else ' ERROR
        If mess.ResponseCode = 0 Then mess.ResponseCode = 400
        If mess.ResponseString = "" Or mess.ResponseString = Null Then mess.ResponseString = "error"
        'If mess.ResponseMessage = "" Then mess.ResponseMessage = "Bad Request"
        If mess.ResponseError = "" Then mess.ResponseError = "Bad Request"
        mess.ResponseMessage = Null
    End If
    If mess.ContentType = "" Then mess.ContentType = CONTENT_TYPE_JSON
    If mess.ResponseData.IsInitialized = False Then mess.ResponseData.Initialize   
    ' Override Status Code
    If mess.ResponseCode < 200 Or  mess.ResponseCode > 299 Then
        resp.Status = 200
    Else
        resp.Status = mess.ResponseCode
    End If
    resp.ContentType = mess.ContentType
    Dim Map1 As Map = CreateMap("s": mess.ResponseString, "a": mess.ResponseCode, "r": mess.ResponseData, "m": mess.ResponseMessage, "e": mess.ResponseError)
    resp.Write(Map2Json(Map1))
End Sub