(Visual FoxPro) (using AWS Signature Version 2) Streaming Download to File

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.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loRest
LOCAL lnBTls
LOCAL lnPort
LOCAL lnBAutoReconnect
LOCAL lnSuccess
LOCAL loAuthAws
LOCAL lnResponseStatusCode
LOCAL loBodyStream
LOCAL lcErrResponse

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Rest')
loRest = CreateObject('Chilkat.Rest')

* Connect to the Amazon AWS REST server.
lnBTls = 1
lnPort = 443
lnBAutoReconnect = 1
* The file is located in the bucket named "chilkat100", which becomes part of the domain:
lnSuccess = loRest.Connect("chilkat100.s3.amazonaws.com",lnPort,lnBTls,lnBAutoReconnect)

* Provide AWS credentials for the REST call.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.AuthAws')
loAuthAws = CreateObject('Chilkat.AuthAws')
loAuthAws.AccessKey = "AWS_ACCESS_KEY"
loAuthAws.SecretKey = "AWS_SECRET_KEY"
loAuthAws.ServiceName = "s3"

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

lnSuccess = loRest.SetAuthAws(loAuthAws)

* Send the request to download the JPG.
lnSuccess = loRest.SendReqNoBody("GET","/starfish.jpg")
IF (lnSuccess <> 1) THEN
    ? loRest.LastErrorText
    RELEASE loRest
    RELEASE loAuthAws
    CANCEL
ENDIF

* Read the response header.
lnResponseStatusCode = loRest.ReadResponseHeader()
IF (lnResponseStatusCode < 0) THEN
    ? loRest.LastErrorText
    RELEASE loRest
    RELEASE loAuthAws
    CANCEL
ENDIF

? "Response status code = " + STR(lnResponseStatusCode)

* 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 (lnResponseStatusCode = 200) THEN

    * For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Stream')
    loBodyStream = CreateObject('Chilkat.Stream')

    * The stream's sink will be a file.
    loBodyStream.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.
    lnSuccess = loRest.ReadRespBodyStream(loBodyStream,1)
    IF (lnSuccess <> 1) THEN
        ? loRest.LastErrorText
        RELEASE loRest
        RELEASE loAuthAws
        RELEASE loBodyStream
        CANCEL
    ENDIF

    ? "Successfully received the JPG file."

ELSE
    lcErrResponse = loRest.ReadRespBodyString()
    IF (loRest.LastMethodSuccess <> 1) THEN
        ? loRest.LastErrorText
    ELSE
        ? lcErrResponse
    ENDIF

ENDIF

RELEASE loRest
RELEASE loAuthAws
RELEASE loBodyStream