PowerBuilder

(using AWS Signature Version 2) Streaming Download to File

See more Amazon S3 (new) Examples

The main purpose of this example is to demonstrate how to use the older Signature Version 2 authentication w/ S3. It uses V2 authentication to download a file. PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Rest
integer li_BTls
integer li_Port
integer li_BAutoReconnect
oleobject loo_AuthAws
integer li_ResponseStatusCode
oleobject loo_BodyStream
string ls_ErrResponse

li_Success = 0

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

loo_Rest = create oleobject
li_rc = loo_Rest.ConnectToNewObject("Chilkat.Rest")
if li_rc < 0 then
    destroy loo_Rest
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// Connect to the Amazon AWS REST server.
li_BTls = 1
li_Port = 443
li_BAutoReconnect = 1
// The file is located in the bucket named "chilkat100", which becomes part of the domain:
li_Success = loo_Rest.Connect("chilkat100.s3.amazonaws.com",li_Port,li_BTls,li_BAutoReconnect)

// Provide AWS credentials for the REST call.
loo_AuthAws = create oleobject
li_rc = loo_AuthAws.ConnectToNewObject("Chilkat.AuthAws")

loo_AuthAws.AccessKey = "AWS_ACCESS_KEY"
loo_AuthAws.SecretKey = "AWS_SECRET_KEY"
loo_AuthAws.ServiceName = "s3"

// For AWS Signature Version 2, the following two properties need to be set:
loo_AuthAws.SignatureVersion = 2
// See http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html#ConstructingTheCanonicalizedResourceElement
loo_AuthAws.CanonicalizedResourceV2 = "/chilkat100/starfish.jpg"

li_Success = loo_Rest.SetAuthAws(loo_AuthAws)

// Send the request to download the JPG.
li_Success = loo_Rest.SendReqNoBody("GET","/starfish.jpg")
if li_Success <> 1 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    destroy loo_AuthAws
    return
end if

// Read the response header.
li_ResponseStatusCode = loo_Rest.ReadResponseHeader()
if li_ResponseStatusCode < 0 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    destroy loo_AuthAws
    return
end if

Write-Debug "Response status code = " + string(li_ResponseStatusCode)

// We expect a 200 response status if the JPG data is coming.
// Otherwise, we'll get a string response body with an error message(or no response body).
if li_ResponseStatusCode = 200 then

    loo_BodyStream = create oleobject
    li_rc = loo_BodyStream.ConnectToNewObject("Chilkat.Stream")

    // The stream's sink will be a file.
    loo_BodyStream.SinkFile = "qa_output/starfish.jpg"

    // Read the response body to the stream.  Given that we've
    // set the stream's sink to a file, it will stream directly
    // to the file.
    li_Success = loo_Rest.ReadRespBodyStream(loo_BodyStream,1)
    if li_Success <> 1 then
        Write-Debug loo_Rest.LastErrorText
        destroy loo_Rest
        destroy loo_AuthAws
        destroy loo_BodyStream
        return
    end if

    Write-Debug "Successfully received the JPG file."

else
    ls_ErrResponse = loo_Rest.ReadRespBodyString()
    if loo_Rest.LastMethodSuccess <> 1 then
        Write-Debug loo_Rest.LastErrorText
    else
        Write-Debug ls_ErrResponse
    end if

end if



destroy loo_Rest
destroy loo_AuthAws
destroy loo_BodyStream