Swift

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

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

func chilkatTest() {
    var success: Bool = false

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

    let rest = CkoRest()!

    // Connect to the Amazon AWS REST server.
    var bTls: Bool = true
    var port: Int = 443
    var bAutoReconnect: Bool = true
    success = rest.connect(hostname: "s3.amazonaws.com", port: port, tls: bTls, autoReconnect: 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.
    let authAws = CkoAuthAws()!
    authAws.accessKey = "AWS_ACCESS_KEY"
    authAws.secretKey = "AWS_SECRET_KEY"
    authAws.serviceName = "s3"
    success = rest.setAuthAws(authProvider: authAws)

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

    // Send the request to download the JPG.
    success = rest.sendReqNoBody(httpVerb: "GET", uriPath: "/starfish.jpg")
    if success != true {
        print("\(rest.lastErrorText!)")
        return
    }

    // Read the response header.
    var responseStatusCode: Int = rest.readResponseHeader().intValue
    if responseStatusCode < 0 {
        print("\(rest.lastErrorText!)")
        return
    }

    print("Response status code = \(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 responseStatusCode == 200 {

        let bodyStream = CkoStream()!

        // The stream's sink will be a file.
        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.
        success = rest.readRespBodyStream(stream: bodyStream, autoSetStreamCharset: true)
        if success != true {
            print("\(rest.lastErrorText!)")
            return
        }

        print("Successfully received the JPG file.")

    }
    else {
        var errResponse: String? = rest.readRespBodyString()
        if rest.lastMethodSuccess != true {
            print("\(rest.lastErrorText!)")
        }
        else {
            print("\(errResponse!)")
        }

    }


}