Converting PDF file to text in VB.NET in VS2022

PdfTextExtractor.vb

Imports System.IO
Imports System.Net
Imports System.Text
Imports System.Text.Json

Namespace PdfTextExtractor
    Public Class Program
        ' When you have your own client ID and secret, specify them here:
        Private Const CLIENT_ID As String = "FREE_TRIAL_ACCOUNT"
        Private Const CLIENT_SECRET As String = "PUBLIC_SECRET"
        Private Const API_URL As String = "https://api.whatsmate.net/v1/pdf/extract?url="

        Shared Sub Main(ByVal args As String())
            ' TODO: Specify the URL of your small PDF document (less than 1MB and 10 pages)
            ' To extract text from bigger PDF document, you need to use the async method.
            Dim pdfUrl As String = "https://ospi.k12.wa.us/sites/default/files/2023-08/jokes.pdf"

            Try
                Dim text As String = ExtractText(pdfUrl)

                Console.WriteLine("===============================")
                Console.WriteLine("PDF TEXT IS AS FOLLOWS:")
                Console.WriteLine(text)
                Console.WriteLine("===============================")
            Catch ex As Exception
                Console.WriteLine($"Error: {ex.Message}")
            End Try

            Console.WriteLine("Press Enter to exit.")
            Console.ReadLine()
        End Sub

        Shared Function ExtractText(ByVal pdfUrl As String) As String
            Dim fullUrl As String = API_URL & Uri.EscapeDataString(pdfUrl)

            Dim request As HttpWebRequest = WebRequest.Create(fullUrl)
            request.Method = "GET"
            request.Headers("X-WM-CLIENT-ID") = CLIENT_ID
            request.Headers("X-WM-CLIENT-SECRET") = CLIENT_SECRET

            Using response As HttpWebResponse = DirectCast(request.GetResponse(), HttpWebResponse)
                Using reader As New StreamReader(response.GetResponseStream())
                    Dim jsonResponse As String = reader.ReadToEnd()

                    ' Parse JSON response using System.Text.Json (modern .NET 6+)
                    Using doc As JsonDocument = JsonDocument.Parse(jsonResponse)
                        Dim root As JsonElement = doc.RootElement

                        If root.TryGetProperty("text", root) Then
                            Return root.GetString()
                        ElseIf root.TryGetProperty("error", root) Then
                            Throw New Exception($"API Error: {root.GetString()}")
                        Else
                            Return jsonResponse
                        End If
                    End Using
                End Using
            End Using
        End Function
    End Class
End Namespace