Writing and Reading JSON in VB.net using Newtonsoft - json

Question

This is my first time using JSON and I'm stuck. I'm trying to send a test SMS via http://sms.roamtech.com/smsapi/. The format is:
Send message format(json).
{
"result":{
"account":"xxxx",
"user":"xxxx",
"password":"xxxxxxxx",
"requestType":"BULK",
"alphanumeric":"xxxxxxxx",
"data":{
"linkid":"xxxxxxx",
"msisdn":"xxxxxxxxxxx",
"networkid":"1",
"message":"xxxxxxxxxxxx",
"callback":"http//test"
}
}
}
So, this is what I've come up with after reviewing various posts on this and other sites:
Imports Newtonsoft.Json
Imports Newtonsoft.Json.Linq
Imports System.IO
Imports System.Net
Imports System.Text
Module modJSON
Public Class clsResult
Public account As String
Public user As String
Public password As String
Public requestType As String
Public alphanumeric As String
Public data As New clsData
End Class
Public Class clsData
Public linkid As String
Public msisdn As String
Public networkid As String
Public message As String
Public callback As String
End Class
Public Class clsPOST
Public result As New clsResult
End Class
Public Sub chkJSON()
Dim r As New clsResult
Dim d As New clsData
Dim x As New clsPOST
r.account = "8852"
r.user = "username"
r.password = "password"
r.requestType = "BULK"
r.alphanumeric = "SMSLEO"
d.linkid = "1001"
d.msisdn = "2547xxxxxxxx"
d.networkid = "1"
d.message = "Just a test"
d.callback = "http://infiniti-africa.com/json"
r.data = d
x.result = r
Dim uriRoam As New Uri("http://sms.roamtech.com/smsapi")
Dim strJSON = JsonConvert.SerializeObject(x, Formatting.Indented)
Dim bytJSON = Encoding.UTF8.GetBytes(strJSON)
Dim result_post = SendRequest(uriRoam, bytJSON, "application/json", "POST")
MsgBox(result_post)
End Sub
Private Function SendRequest(uri As Uri, jsonDataBytes As Byte(), contentType As String, method As String) As String
Dim req As WebRequest = WebRequest.Create(uri)
req.ContentType = contentType
req.Method = method
req.ContentLength = jsonDataBytes.Length
Dim stream = req.GetRequestStream()
stream.Write(jsonDataBytes, 0, jsonDataBytes.Length)
stream.Close()
Dim response = req.GetResponse().GetResponseStream()
Dim reader As New StreamReader(response)
Dim res = reader.ReadToEnd()
reader.Close()
response.Close()
Return res
End Function
End Module
The string strJSONseems to contain the correct key:value combinations. However, the code doesn't send the test SMS and I don't get any response. 'SendRequest' returns an empty string.
Also, I'm not sure what to use for the "callback" url, which is where the delivery report is forwarded.
Note:
1. "linkid" is a unique message ID
2. "msidn" is the recipient phone number
Any help is appreciated.
I have also tried using the following class:
Public Class JsonPost
Private urlToPost As String = ""
Public Sub New(ByVal urlToPost As String)
Me.urlToPost = urlToPost
End Sub
Public Function postData(pstData As Byte()) As Boolean
Dim webClient As New WebClient()
Dim resByte As Byte()
Dim resString As String
Try
webClient.Headers("content-type") = "application/json"
resByte = webClient.UploadData(Me.urlToPost, "post", pstData)
resString = Encoding.Default.GetString(resByte)
Console.WriteLine(resString)
webClient.Dispose()
Return True
Catch ex As Exception
Console.WriteLine(ex.Message)
End Try
Return False
End Function
End Class
Then calling:
Dim strJSON = JsonConvert.SerializeObject(x)
Dim bytJSON = Encoding.UTF8.GetBytes(strJSON)
Dim jsonPost As New JsonPost("http://sms.roamtech.com/smsapi")
jsonPost.postData(bytJSON)
I'm still getting nothing. Been struggling with this for three days now. Any ideas anyone?

Answer 1

Turns out I've been stressing for four days over a trailing slash (/). The API URL is:
http://sms.roamtech.com/smsapi/
While I've been using:
http://sms.roamtech.com/smsapi
Lesson learnt.