B4X
B4X
Upload File in Blocks (with Content-MD5 header) and Commit the Block List
See more Azure Cloud Storage Examples
Demonstrates how to upload a file in blocks and then commit the block list. This example includes a Content-MD5 header for each block.Chilkat B4X Downloads
Dim success As Boolean = False
' Azure Blob Service Example: Upload a file in blocks, and then commit the block list.
' See also: https://msdn.microsoft.com/en-us/library/azure/dd135726.aspx
' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.
Dim rest As ChilkatRest
rest.Initialize("rest")
' Connect to the Azure Storage Blob Service
Dim bTls As Boolean = True
Dim port As Int = 443
Dim bAutoReconnect As Boolean = True
' In this example, the storage account name is "chilkat".
success = rest.Connect("chilkat.blob.core.windows.net", port, bTls, bAutoReconnect)
If success <> True Then
Log(rest.LastErrorText)
Return
End If
' Provide Azure Cloud credentials for the REST call.
Dim azAuth As ChilkatAuthAzureStorage
azAuth.Initialize
azAuth.AccessKey = "AZURE_ACCESS_KEY"
' The account name used here should match the 1st part of the domain passed in the call to Connect (above).
azAuth.Account = "chilkat"
azAuth.Scheme = "SharedKey"
azAuth.Service = "Blob"
' This causes the "x-ms-version: 2021-08-06" header to be automatically added.
azAuth.XMsVersion = "2021-08-06"
success = rest.SetAuthAzureStorage(azAuth)
' Note: The application does not need to explicitly set the following
' headers: Content-Length, x-ms-date, Authorization. These headers
' are automatically set by Chilkat.
' As the blocks are uploaded, we'll keep an XML block list for the subsequent commit..
Dim xml As ChilkatXml
xml.Initialize
xml.Tag = "BlockList"
' Any type of file can be uploaded in this way. It can a text file, binary file, anything...
' This example will upload an XML file that is approximately 275K in size. It can be downloaded
' at http://www.chilkatsoft.com/hamlet.xml
Dim fac As ChilkatFileAccess
fac.Initialize
success = fac.OpenForRead("qa_data/xml/hamlet.xml")
' Assuming success for the example..
' We'll upload in 16K blocks (normally a program would upload in larger block sizes than this,
' but this is just an example...)
Dim blockSize As Int = 16384
' How many 16K blocks? (Including 1 for the last partial block)
Dim numBlocks As Int = fac.GetNumBlocks(blockSize)
Dim crypt As ChilkatCrypt2
crypt.Initialize("crypt")
crypt.HashAlgorithm = "md5"
Dim sbResponseBody As ChilkatStringBuilder
sbResponseBody.Initialize
Dim uriPath As ChilkatStringBuilder
uriPath.Initialize
Dim blockId As String
Dim dataBlock As ChilkatBinData
dataBlock.Initialize
Dim contentMd5 As String
Dim i As Int = 0
Do While i < numBlocks
dataBlock.Clear
success = fac.ReadBlockBd(i, blockSize, dataBlock)
If success = False Then
Log(fac.LastErrorText)
Return
End If
' Generate a base64 block ID.
' (Chilkat provides a helper method named GenBlockId to make this easy)
' A pre-base64 encoded block ID length of 4 is sufficient in this case because
' this file certainly won't have more than 99,999 blocks..
blockId = fac.GenBlockId(i, 4, "base64")
' Add this blockId to the list of blocks to be committed.
xml.NewChild2("Latest", blockId)
' Build the URI path
uriPath.Clear
success = uriPath.Append("/mycontainer/hamlet.xml?comp=block&blockId=")
success = uriPath.Append(blockId)
contentMd5 = crypt.HashBdENC(dataBlock)
rest.AddHeader("Content-MD5", contentMd5)
' Upload this block..
sbResponseBody.Clear
success = rest.FullRequestBd("PUT", uriPath.GetAsString, dataBlock, sbResponseBody)
If success = False Then
Log(rest.LastErrorText)
Return
End If
' Verify that we received a 201 status code.
If rest.ResponseStatusCode <> 201 Then
' Examine the request/response to see what happened.
Log("response status code = " & rest.ResponseStatusCode)
Log("response status text = " & rest.ResponseStatusText)
Log("response header: " & rest.ResponseHeader)
Log("response body (if any): " & sbResponseBody.GetAsString)
Log("---")
Log("LastRequestStartLine: " & rest.LastRequestStartLine)
Log("LastRequestHeader: " & rest.LastRequestHeader)
Return
End If
i = i + 1
Loop
fac.FileClose
' Now commit the blocks.
' Let's have a look at the XML that will commit the blocks:
Dim xmlStr As String = xml.GetXml
Log(xmlStr)
' The XML will look like this:
' <?xml version="1.0" encoding="utf-8" ?>
' <BlockList>
' <Latest>MDAwMA==</Latest>
' <Latest>MDAwMQ==</Latest>
' <Latest>MDAwMg==</Latest>
' <Latest>MDAwMw==</Latest>
' <Latest>MDAwNA==</Latest>
' <Latest>MDAwNQ==</Latest>
' <Latest>MDAwNg==</Latest>
' <Latest>MDAwNw==</Latest>
' <Latest>MDAwOA==</Latest>
' <Latest>MDAwOQ==</Latest>
' <Latest>MDAxMA==</Latest>
' <Latest>MDAxMQ==</Latest>
' <Latest>MDAxMg==</Latest>
' <Latest>MDAxMw==</Latest>
' <Latest>MDAxNA==</Latest>
' <Latest>MDAxNQ==</Latest>
' <Latest>MDAxNg==</Latest>
' <Latest>MDAxNw==</Latest>
' </BlockList>
' --------------------------------------------------------------------------
' IMPORTANT: Remove the Content-MD5 header previously set in the loop above.
' --------------------------------------------------------------------------
rest.RemoveHeader("Content-MD5")
' Send the PUT Block List...
Dim responseStr As String = rest.FullRequestString("PUT", "/mycontainer/hamlet.xml?comp=blocklist", xmlStr)
If rest.LastMethodSuccess <> True Then
Log(rest.LastErrorText)
Return
End If
' When successful, the Azure Storage service will respond with a 201 response status code,
' with no response body.
If rest.ResponseStatusCode <> 201 Then
' Examine the request/response to see what happened.
Log("response status code = " & rest.ResponseStatusCode)
Log("response status text = " & rest.ResponseStatusText)
Log("response header: " & rest.ResponseHeader)
Log("response body (if any): " & responseStr)
Log("---")
Log("LastRequestStartLine: " & rest.LastRequestStartLine)
Log("LastRequestHeader: " & rest.LastRequestHeader)
Return
End If
Log("Success.")