VB.NET

Read the REST Response Body into BinData

Demonstrates Rest.ReadRespBd, which reads the response body as raw bytes into a BinData, replacing its previous contents.

The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background. The staged request model separates sending from reading: a SendReq method transmits the request, ReadResponseHeader reads the status line and headers, and a ReadResp method reads the body. This gives fine control over large or streamed messages compared with the single-call full-request methods.

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VB.NET

Dim success As Boolean = False

Dim rest As New Chilkat.Rest
Dim bTls As Boolean = True
Dim bAutoReconnect As Boolean = True
success = rest.Connect("example.com",443,bTls,bAutoReconnect)
If (success = False) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


'  The file paths are relative to the application's current working directory.  Absolute paths
'  may also be used.  Supply the paths appropriate to your own environment.

success = rest.SendReqNoBody("GET","/api/images/1")
If (success = False) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


Dim statusCode As Integer = rest.ReadResponseHeader()
If (statusCode < 0) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


'  Check for the expected success status code.  If the response is not 200, the body is likely
'  error text formatted as JSON, XML, or HTML rather than the expected binary content.  In that case
'  read the body as text, report it, and return.
If (statusCode <> 200) Then
    Dim sbError As New Chilkat.StringBuilder
    success = rest.ReadRespSb(sbError)
    If (success = False) Then
        Debug.WriteLine(rest.LastErrorText)
        Exit Sub
    End If

    Debug.WriteLine("Request failed with status code " & statusCode)
    Debug.WriteLine(sbError.GetAsString())
    Exit Sub
End If


'  The status code is 200.  Read the response body as raw bytes into a BinData.
Dim bdResponse As New Chilkat.BinData
success = rest.ReadRespBd(bdResponse)
If (success = False) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


Dim bSaved As Boolean = bdResponse.WriteFile("qa_output/image.png")
If (bSaved <> True) Then
    Debug.WriteLine("Failed to save the response body.")
    Exit Sub
End If

Debug.WriteLine("Received " & bdResponse.NumBytes & " bytes.")