Xbase++

REST Stream Response to File (Streaming Download) (Amazon S3)

See more Amazon S3 (new) Examples

Demonstrates how to stream the response body directly to a file. (The example shows how to stream a JPG from the Amazon S3 service.) Xbase++

LOCAL nSuccess
LOCAL oRest
LOCAL nBTls
LOCAL nPort
LOCAL nBAutoReconnect
LOCAL oAuthAws
LOCAL nResponseStatusCode
LOCAL oBodyStream
LOCAL cErrResponse

nSuccess := 0

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

oRest := CreateObject("Chilkat.Rest")

//  Connect to the Amazon AWS REST server.
nBTls := 1
nPort := 443
nBAutoReconnect := 1
nSuccess := oRest:Connect("s3.amazonaws.com", nPort, nBTls, nBAutoReconnect)

//  ----------------------------------------------------------------------------
//  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.
oAuthAws := CreateObject("Chilkat.AuthAws")
oAuthAws:AccessKey := "AWS_ACCESS_KEY"
oAuthAws:SecretKey := "AWS_SECRET_KEY"
oAuthAws:ServiceName := "s3"
nSuccess := oRest:SetAuthAws(oAuthAws)

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

//  Send the request to download the JPG.
nSuccess := oRest:SendReqNoBody("GET", "/starfish.jpg")
IF (nSuccess != 1)
    ? oRest:LastErrorText
    oRest:destroy()
    oAuthAws:destroy()
    RETURN
ENDIF

//  Read the response header.
nResponseStatusCode := oRest:ReadResponseHeader()
IF (nResponseStatusCode < 0)
    ? oRest:LastErrorText
    oRest:destroy()
    oAuthAws:destroy()
    RETURN
ENDIF

? "Response status code = " + Str(nResponseStatusCode)

//  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 (nResponseStatusCode == 200)

    oBodyStream := CreateObject("Chilkat.Stream")

    //  The stream's sink will be a file.
    oBodyStream: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.
    nSuccess := oRest:ReadRespBodyStream(oBodyStream, 1)
    IF (nSuccess != 1)
        ? oRest:LastErrorText
        oRest:destroy()
        oAuthAws:destroy()
        oBodyStream:destroy()
        RETURN
    ENDIF

    ? "Successfully received the JPG file."

ELSE
    cErrResponse := oRest:ReadRespBodyString()
    IF (oRest:LastMethodSuccess != 1)
        ? oRest:LastErrorText
    ELSE
        ? cErrResponse
    ENDIF

ENDIF

oRest:destroy()
oAuthAws:destroy()
oBodyStream:destroy()