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

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

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

loRest = createobject("CkRest")

// Connect to the Amazon AWS REST server.
llBTls = .T.
lnPort = 443
llBAutoReconnect = .T.
llSuccess = loRest.Connect("s3.amazonaws.com",lnPort,llBTls,llBAutoReconnect)

// ----------------------------------------------------------------------------
// 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.
loAuthAws = createobject("CkAuthAws")
loAuthAws.AccessKey = "AWS_ACCESS_KEY"
loAuthAws.SecretKey = "AWS_SECRET_KEY"
loAuthAws.ServiceName = "s3"
llSuccess = loRest.SetAuthAws(loAuthAws)

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

// Send the request to download the JPG.
llSuccess = loRest.SendReqNoBody("GET","/starfish.jpg")
if (llSuccess <> .T.) then
    ? loRest.LastErrorText
    release loRest
    release loAuthAws
    return
endif

// Read the response header.
lnResponseStatusCode = loRest.ReadResponseHeader()
if (lnResponseStatusCode < 0) then
    ? loRest.LastErrorText
    release loRest
    release loAuthAws
    return
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

    loBodyStream = createobject("CkStream")

    // 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.
    llSuccess = loRest.ReadRespBodyStream(loBodyStream,.T.)
    if (llSuccess <> .T.) then
        ? loRest.LastErrorText
        release loRest
        release loAuthAws
        release loBodyStream
        return
    endif

    ? "Successfully received the JPG file."

else
    lcErrResponse = loRest.ReadRespBodyString()
    if (loRest.LastMethodSuccess <> .T.) then
        ? loRest.LastErrorText
    else
        ? lcErrResponse
    endif

endif



release loRest
release loAuthAws
release loBodyStream