How to use Bit.ly API to shorten URL in VB.NET

The use of shortened URL which was popularized by Twitter's tweets (autolinks) is now can be integrated on other applications by using APIs. Bit.ly, one of the most widely used shortening service is now offering free developer tools to programmers to integrate Bit.ly service on their apps. For this blog entry, I will show you how to use Bit.ly APIs on your application to shorten a given long URL. First, you need to sign-up for an account at bit.ly to receive your API key that looks like this "R_387dd73d526f14c196b235ef63d1b709".

Before we can start our project, please make sure you have the following.
- Bit.ly Login
- API key
- Bit.ly API url which is "http://api.bit.ly/shorten?version=2.0.1&format=xml"

On your Console project, add the following imports.


Imports System.Xml
Imports System.IO
Imports System.Net

Add the following functions.


   'function that accept long URL and returns the bit.ly shortened URL
    Public Function GetBitLyShortUrl(ByVal url As String) As String

        Dim lreturn As String = ""

        Dim doc As XmlDocument
        doc = LoadXMLResponse(url)

        If Not doc.DocumentElement Is Nothing Then
            Dim shortenedNode As XmlNode = doc.DocumentElement.SelectSingleNode("results/nodeKeyVal/shortUrl")
            If Not shortenedNode Is Nothing Then
                lreturn = shortenedNode.InnerText
            Else
                lreturn = "Error while retrieving shortened URL"
            End If
        Else
            lreturn = "Error while retrieving shortened URL"
        End If

        Return lreturn
    End Function
    'Load the return XML reponse
    Private Function LoadXMLResponse(ByVal url As String) As XmlDocument

        Dim doc As New XmlDocument

        Try

            ' Load the XML response into an XML Document and return it.
            doc.LoadXml(ReadBitLyResult(BitlyUrl + "&longUrl=" + url))
            Return doc

        Catch e As Exception

            Return New XmlDocument()
        End Try
    End Function

    ' Fetches a result from bit.ly provided the URL submitted
    Private Function ReadBitLyResult(ByVal url As String) As String
        Dim client As New WebClient

        Try

            Using reader As New StreamReader(client.OpenRead(url))
                ' Read all of the response
                Return reader.ReadToEnd()
                reader.Close()
            End Using

        Catch e As Exception
            Throw e
        End Try

    End Function

Where:
- GetBitLyShortUrl is the main function that accepts a long URL and returns a short URL from Bit.ly
- LoadXMLResponse is the function Load the XML response file to a XML document.
- ReadBitLyResult is the function that will fetch the result from Bit.ly

Lastly, copy and paste the following code on your Main function.


    Sub Main()
        Dim loginBitly As String = "foxtrot0911"
        Dim apiKey As String = "R_387dd73d526f14c196b235ef63d1b709"
        Dim urlToShorten As String = "http://www.fryan0911.com"
        BitlyUrl &= "&login=" & loginBitly & "&apiKey=" & apiKey

        Console.WriteLine(urlToShorten & "=>" & GetBitLyShortUrl(urlToShorten))
        Console.ReadKey()

    End Sub

Now run your project. The console should display similar to this screenshot.