(Go) S3 Complete a Multipart Upload

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>

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

    // 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.

    xmlInit := chilkat.NewXml()
    success := xmlInit.LoadXmlFile("s3_multipart_uploads/initiate.xml")
    if success != true {
        fmt.Println("Did not find the initiate.xml XML file.")
        xmlInit.DisposeXml()
        return
    }

    uploadId := xmlInit.GetChildContent("UploadId")
    fmt.Println("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.)
    xmlPartsList := chilkat.NewXml()
    success = xmlPartsList.LoadXmlFile("s3_multipart_uploads/partsList.xml")
    if success != true {
        fmt.Println("Did not find the partsList.xml XML file.")
        xmlInit.DisposeXml()
        xmlPartsList.DisposeXml()
        return
    }

    rest := chilkat.NewRest()

    // Connect to the Amazon AWS REST server.
    bTls := true
    port := 443
    bAutoReconnect := 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.
    authAws := chilkat.NewAuthAws()
    authAws.SetAccessKey("AWS_ACCESS_KEY")
    authAws.SetSecretKey("AWS_SECRET_KEY")
    authAws.SetServiceName("s3")

    success = rest.SetAuthAws(authAws)

    // Set the bucket name via the HOST header.
    // In this case, the bucket name is "chilkat100".
    rest.SetHost("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".
    responseXml := rest.FullRequestString("POST","/somethingBig.zip",*xmlPartsList.GetXml())
    if rest.LastMethodSuccess() != true {
        fmt.Println(rest.LastErrorText())
        xmlInit.DisposeXml()
        xmlPartsList.DisposeXml()
        rest.DisposeRest()
        authAws.DisposeAuthAws()
        return
    }

    // When successful, the S3 Storage service will respond with a 200 response code,
    // with an XML body.  
    if rest.ResponseStatusCode() != 200 {
        // Examine the request/response to see what happened.
        fmt.Println("response status code = ", rest.ResponseStatusCode())
        fmt.Println("response status text = ", rest.ResponseStatusText())
        fmt.Println("response header: ", rest.ResponseHeader())
        fmt.Println("response body: ", *responseXml)
        fmt.Println("---")
        fmt.Println("LastRequestStartLine: ", rest.LastRequestStartLine())
        fmt.Println("LastRequestHeader: ", rest.LastRequestHeader())
    }

    // Load the XML response into Chilkat XMl and emit via GetXml to see the XML in a pretty-printed (indented) readable format.
    xml := chilkat.NewXml()
    xml.LoadXml(*responseXml)
    fmt.Println(*xml.GetXml())
    fmt.Println("----")

    fmt.Println("Multipart upload completed.")

    xmlInit.DisposeXml()
    xmlPartsList.DisposeXml()
    rest.DisposeRest()
    authAws.DisposeAuthAws()
    xml.DisposeXml()