VB.NET Server side code to send C2DM messages for android?

VB.NET Server side code to send C2DM messages to the Google servers.

This code gets a Google "ClientLogin" and then sends a message to the Google C2DM servers. You will need a RegistryID from a Android phone app for this to work properly.

You will also need to get the "Google.GData.Client" client libs. The libs simplify your life because then you don't need to figure out SSL and stuff. More info here: http://code.google.com/apis/gdata/docs/auth/clientlogin.html

Imports Google.GData.Client

Module Module1

    Private Const C2DM_SEND_URL As String = "https://android.apis.google.com/c2dm/send"

    Private Const CLIENT_SEND_URL As String = "https://www.google.com/accounts/ClientLogin"

    Private googleAuthToken As String = Nothing

    'This is my Phone's ID for this app. It will be sent to the GServer so that google knows where to send the message

    Private RegID As String = "" '

    

    Sub Main()

        GetClientLogin()

        SendRequest()

    End Sub

    Private Sub GetClientLogin()

        Dim email As String = "youremail@gmail.com"

        Dim password As String = "password"

        

        Dim authFactory As New GDataGAuthRequestFactory("cl", "yourCompany-c2dmServerPOC-v1")

        Dim cred As New GDataCredentials(email, password)

        authFactory.AccountType = "GOOGLE"

        'This specifies that the token is going to point to the C2DM Service

        authFactory.Service = "ac2dm"

        ' This gets the Google ClientLogon token

        Try

            googleAuthToken = authFactory.QueryAuthToken(cred)

        Catch ex As Exception

            Console.WriteLine("Error when retrieving Google Token")

        End Try

        

    End Sub

    Private Sub SendRequest()

        'Build the POST Body

        Dim body As String = Nothing

        body += "collapse_key=nothing"

        body += "&data.burst_id=" + "12345"

        body += "&registration_id=" + RegID

        'Build the POST Header

        Dim webReq = DirectCast(WebRequest.Create(C2DM_SEND_URL), HttpWebRequest)

        webReq.ContentLength = body.Length

        webReq.Method = "POST"

        webReq.ContentType = "application/x-www-form-urlencoded"

        webReq.UserAgent = "C2DM-InfoBurst"

        webReq.Headers.Add("Authorization: GoogleLogin auth=" & googleAuthToken)

        'This is important because you have to 'ignore' the SSL check. We could build this out further 

        ServicePointManager.ServerCertificateValidationCallback = Function() True

        'This POSTs the call 

        Using webReqStream = New StreamWriter(webReq.GetRequestStream(), Encoding.ASCII)

            Dim data = body

            webReqStream.Write(data)

            webReqStream.Close()

        End Using

        'This gets the response

        Dim webResp As HttpWebResponse

        Dim ResponseStatus As String = ""

        Dim ResponseCode As String = ""

        Dim MessageId As String = ""

        Dim responseBody = ""

        Try

            'Gets the response in HttpWebResponse

            webResp = TryCast(webReq.GetResponse(), HttpWebResponse)

            'Gets the Response body

            responseBody = (New StreamReader(webResp.GetResponseStream())).ReadToEnd()

            If responseBody.StartsWith("id=") Then

                'Get the message ID

                MessageId = responseBody.Substring(3).Trim()

            Else

                'Handle the type of error

                If responseBody.StartsWith("Error=") Then

                    Dim wrErr = responseBody.Substring(responseBody.IndexOf("Error=") + 6)

                    Select Case wrErr.ToLower().Trim()

                        Case "quotaexceeded"

                            ResponseStatus = MessageTransportResponseStatus.QuotaExceeded

                            Exit Select

                        Case "devicequotaexceeded"

                            ResponseStatus = MessageTransportResponseStatus.DeviceQuotaExceeded

                            Exit Select

                        Case "invalidregistration"

                            ResponseStatus = MessageTransportResponseStatus.InvalidRegistration

                            Exit Select

                        Case "notregistered"

                            ResponseStatus = MessageTransportResponseStatus.NotRegistered

                            Exit Select

                        Case "messagetoobig"

                            ResponseStatus = MessageTransportResponseStatus.MessageTooBig

                            Exit Select

                        Case "missingcollapsekey"

                            ResponseStatus = MessageTransportResponseStatus.MissingCollapseKey

                            Exit Select

                        Case Else

                            ResponseStatus = MessageTransportResponseStatus.[Error]

                            Exit Select

                    End Select

                End If

            End If

        Catch ex As Exception

            If webResp.StatusCode = HttpStatusCode.Unauthorized Then

                '401 bad auth token

                ResponseCode = MessageTransportResponseCode.InvalidAuthToken

                ResponseStatus = MessageTransportResponseStatus.[Error]

            ElseIf webResp.StatusCode = HttpStatusCode.ServiceUnavailable Then

                'First try grabbing the retry-after header and parsing it.

                Dim retryAfter As New TimeSpan(0, 0, 120)

                Dim wrRetryAfter = webResp.GetResponseHeader("Retry-After")

                If Not String.IsNullOrEmpty(wrRetryAfter) Then

                    Dim wrRetryAfterDate As DateTime = DateTime.UtcNow

                    If DateTime.TryParse(wrRetryAfter, wrRetryAfterDate) Then

                        retryAfter = wrRetryAfterDate - DateTime.UtcNow

                    Else

                        Dim wrRetryAfterSeconds As Integer = 120

                        If Integer.TryParse(wrRetryAfter, wrRetryAfterSeconds) Then

                            retryAfter = New TimeSpan(0, 0, wrRetryAfterSeconds)

                        End If

                    End If

                End If

                '503 exponential backoff, get retry-after header

                ResponseCode = MessageTransportResponseCode.ServiceUnavailable

                ResponseStatus = MessageTransportResponseStatus.[Error]

            End If

        End Try

    End Sub

    Public Enum MessageTransportResponseCode

        Ok

        [Error]

        ServiceUnavailable

        InvalidAuthToken

    End Enum

    Public Enum MessageTransportResponseStatus

        Ok

        [Error]

        QuotaExceeded

        DeviceQuotaExceeded

        InvalidRegistration

        NotRegistered

        MessageTooBig

        MissingCollapseKey

    End Enum

End Module