B4X

S3 Complete a Multipart Upload

See more Amazon S3 (new) Examples

This operation completes a multipart upload by assembling previously uploaded parts.

Processing of a Complete Multipart Upload request could take several minutes to complete. After Amazon S3 begins processing the request, it sends an HTTP response header that specifies a 200 OK response. While processing is in progress, Amazon S3 periodically sends whitespace characters to keep the connection from timing out. Because a request could fail after the initial 200 OK response has been sent, it is important that you check the response body to determine whether the request succeeded.

This example sends a POST request to complete a multipart upload, which looks like this:

POST /ObjectName?uploadId=UploadId HTTP/1.1
Host: BucketName.s3.amazonaws.com
Date: Date
Content-Length: Size
Authorization: authorization string

<CompleteMultipartUpload>
  <Part>
    <PartNumber>PartNumber</PartNumber>
    <ETag>ETag</ETag>
  </Part>
  ...
</CompleteMultipartUpload>

B4X

Dim success As Boolean = False

'  This example requires the Chilkat API to have been previously unlocked.
'  See Global Unlock Sample for sample code.

'  The 1st step in an S3 multipart upload is to initiate it,
'  as shown here: Initiate S3 Multipart Upload

'  The 2nd step is to upload the parts
'  as shown here: S3 Upload Parts

'  The 3rd and final step (this example) is to complete the multipart upload.

'  Other S3 Multipart Upload Examples:
'  Abort Multipart Upload
'  List Parts

'  When the multipart upload was initiated, an UploadId was provided in the XML response, and it 
'  was saved to a file.  Steps 2 and 3 begin by loading the XML and getting
'  the Upload ID.

Dim xmlInit As ChilkatXml
xmlInit.Initialize
success = xmlInit.LoadXmlFile("s3_multipart_uploads/initiate.xml")
If success <> True Then
    Log("Did not find the initiate.xml XML file.")
    Return
End If


Dim uploadId As String = xmlInit.GetChildContent("UploadId")
Log("UploadId = " & uploadId)

'  We'll also need the XML file that contains a record of the parts
'  with part numbers and ETags.  (This file was produced when parts were being uploaded.)
Dim xmlPartsList As ChilkatXml
xmlPartsList.Initialize
success = xmlPartsList.LoadXmlFile("s3_multipart_uploads/partsList.xml")
If success <> True Then
    Log("Did not find the partsList.xml XML file.")
    Return
End If


Dim rest As ChilkatRest
rest.Initialize("rest")

'  Connect to the Amazon AWS REST server.
Dim bTls As Boolean = True
Dim port As Int = 443
Dim bAutoReconnect As Boolean = True
success = rest.Connect("s3.amazonaws.com", port, bTls, bAutoReconnect)

'  ----------------------------------------------------------------------------
'  Important: For buckets created in regions outside us-east-1,
'  there are three important changes that need to be made.
'  See Working with S3 Buckets in Non-us-east-1 Regions for the details.
'  ----------------------------------------------------------------------------

'  Provide AWS credentials for the REST call.
Dim authAws As ChilkatAuthAws
authAws.Initialize
authAws.AccessKey = "AWS_ACCESS_KEY"
authAws.SecretKey = "AWS_SECRET_KEY"
authAws.ServiceName = "s3"

success = rest.SetAuthAws(authAws)

'  Set the bucket name via the HOST header.
'  In this case, the bucket name is "chilkat100".
rest.Host = "chilkat100.s3.amazonaws.com"

'  The "uploadId=UploadId" must be added as a query parameter.  This allows it to be 
'  incorporated into the AWS signature calculation, which is a requirement.
'  Therefore, we use AddQueryParam:
rest.AddQueryParam("uploadId", uploadId)

'  Our ObjectName in this case is "somethingBig.zip".
Dim responseXml As String = rest.FullRequestString("POST", "/somethingBig.zip", xmlPartsList.GetXml)
If rest.LastMethodSuccess <> True Then
    Log(rest.LastErrorText)
    Return
End If


'  When successful, the S3 Storage service will respond with a 200 response code,
'  with an XML body.  
If rest.ResponseStatusCode <> 200 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: " & responseXml)
    Log("---")
    Log("LastRequestStartLine: " & rest.LastRequestStartLine)
    Log("LastRequestHeader: " & rest.LastRequestHeader)
End If


'  Load the XML response into Chilkat XMl and emit via GetXml to see the XML in a pretty-printed (indented) readable format.
Dim xml As ChilkatXml
xml.Initialize
xml.LoadXml(responseXml)
Log(xml.GetXml)
Log("----")

Log("Multipart upload completed.")