Issues with JSON deserialization - json

Question

I know there are a lot of answers related to this, however, I am unable to parse the response.
This is my JSON that I get back from wrGETURL.OpenRead(sURL):
{
"sessionKey": "TFtG+pGZ0cl0TuUbItWGy9xb9RyoPKGlY2EUF/nHe"
}
This is my JSON that I get back from getcall.OpenRead(sURL):
{
"success": true,
"message": "OK",
"total": 1,
"data": [
{
"domain": "emailsecautomate.co",
"status": "Active",
"order_date": "2017-04-26",
"service": "Email Security",
"company_name": "some name",
"address1": "1 somewhere",
"address2": null,
"city": "somecity",
"state": null,
"country": "some country",
"post_code": null,
"telephone": null,
"email": null,
"po_number": null,
"licenses": "10"
}
]
}
If I comment out the line JsonConvert.DeserializeObject(Of TotalResponse)(st) and output st to a MessageBox this is my JSON:
As you can see it's fine. However if I comment back in that line I get the following error:
401 Unauthorized
This is my full code:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
user = username.Text
pwd = password.Text
'MessageBox.Show(savedUser)
If savedUser IsNot Nothing AndAlso savedUser = "-9999" Then
Dim sqlStatement As String = "INSERT INTO my_table VALUES ('" & user & "','" & pwd & "')"
mobjHost.SetSQL(sqlStatement)
End If
Dim encoded As String = System.Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(user + ":" + pwd))
Dim sURL As String
sURL = "https://xxx.xxx/partners/auth"
Dim wrGETURL As New WebClient()
wrGETURL.Headers.Add("Authorization", "Basic " + encoded)
Try
Dim data As Stream = wrGETURL.OpenRead(sURL)
Dim reader As New StreamReader(data)
Dim s As String = reader.ReadToEnd()
Dim jsonResult = JsonConvert.DeserializeObject(Of IDictionary)(s)
'This line with/without ToString gives the error "objectreference is not set to an instance of Object"
Dim sessionKey = jsonResult.Item("sessionKey").ToString
'Not calling the function for now As even session key gives the same issue
'MessageBox.Show(sessionKey) This shows the sessionKey and everything is fine if this is used
'Me.getCustomers(sessionKey)
wrGETURL.Dispose()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Public Function getCustomers(ByVal sKey As String)
Dim st As String = ""
Dim getcall As New WebClient()
getcall.Headers.Add("USER", user)
getcall.Headers.Add("KEY", sKey)
getcall.Headers.Add("Content-Type", "application/json")
Dim sURL = "https://xxx.xxx/partners/customers"
Try
Dim data As Stream = getcall.OpenRead(sURL)
Dim reader As New StreamReader(data)
st = reader.ReadToEnd()
theResponse = JsonConvert.DeserializeObject(Of TotalResponse)(st)
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
Return True
End Function
These are my classes for the JSON response:
Public Class TotalResponse
Public success As String
Public message As String
Public total As String
Public data As List(Of CustomerInfo)
End Class
Public Class CustomerInfo
Public domain As String
Public status As String
Public order_date As String
Public service As String
Public company_name As String
Public address1 As String
Public address2 As String
Public city As String
Public state As String
Public country As String
Public post_code As String
Public telephone As String
Public email As String
Public po_number As String
Public licenses As String
End Class

Answer 1

I would consider implementing Using for your WebClient and StreamReader objects:
Managed resources are disposed of by the .NET Framework garbage collector (GC) without any extra coding on your part. You do not need a Using block for managed resources. However, you can still use a Using block to force the disposal of a managed resource instead of waiting for the garbage collector.
Please also look at turning Option Strict On which will help you write better code:
Restricts implicit data type conversions to only widening conversions, disallows late binding, and disallows implicit typing that results in an Object type.
I would also look at using the JsonSerializationException within your Catch rather than a general Exception.
With your method getCustomers, consider changing it into a function and returning TotalResponse.
Lastly consider only declaring variables if they are needed and only when they are required. This helps with reducing the amount of code and with the workflow of your code. This can be particular useful for debugging.
With these changes your code would look something like this:
Private Async Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim sessionKey As String = ""
Using wb As New WebClient()
Dim encoded As String = System.Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(user + ":" + pwd))
wb.Headers.Add("Authorization", "Basic " + encoded)
Dim data As Stream = wb.OpenRead("https://xxx.xxx/partners/auth")
Using reader As New StreamReader(data)
Try
Dim result As IDictionary = JsonConvert.DeserializeObject(Of IDictionary)(Await reader.ReadToEndAsync())
sessionKey = result.Item("sessionKey").ToString()
Catch ex As JsonSerializationException
'handle
End Try
End Using
End Using
If Not sessionKey = "" Then
Dim theResponse As TotalResponse = getCustomers(sessionKey)
End If
End Sub
Private Async Function getCustomers(ByVal sKey As String) As TotalResponse
Dim returnResponse As New TotalResponse
Using wb As New WebClient()
wb.Headers.Add("USER", user)
wb.Headers.Add("KEY", sKey)
wb.Headers.Add("Content-Type", "application/json")
Dim data As Stream = wb.OpenRead("https://api-dev.theemaillaundry.net/partners/customers")
Using reader As New StreamReader(data)
Try
returnResponse = JsonConvert.DeserializeObject(Of TotalResponse)(reader.ReadToEndAsync())
Catch ex As JsonSerializationException
'handle
End Try
End Using
End Using
Return returnResponse
End Function
I've also noted your SQL is open to SQL injection. It's outside the scope of this question however consider using SQL parameters. I'm not familiar with mobjHost.SetSQL so unfortunately I can't advise in this area.