(Go) REST Download Binary to Memory (Byte Array) (Amazon S3)

Demonstrates how to make a REST call that returns a binary response body. This example is valid for reasonably small files that fit in memory. The example shows how to download a small JPG from the Amazon S3 service. For larger files, Chilkat provides streaming functionality to stream directly to a file, or to make an asynchronous call where the foreground thread can read the response body stream.

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

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

    rest := chilkat.NewRest()

    // Connect to the Amazon AWS REST server.
    bTls := true
    port := 443
    bAutoReconnect := true
    success := rest.Connect("s3.amazonaws.com",port,bTls,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.
    authAws := chilkat.NewAuthAws()
    authAws.SetAccessKey("AWS_ACCESS_KEY")
    authAws.SetSecretKey("AWS_SECRET_KEY")
    authAws.SetServiceName("s3")
    success = rest.SetAuthAws(authAws)

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

    // Send the request to download the JPG.
    success = rest.SendReqNoBody("GET","/starfish.jpg")
    if success != true {
        fmt.Println(rest.LastErrorText())
        rest.DisposeRest()
        authAws.DisposeAuthAws()
        return
    }

    // Read the response header.
    responseStatusCode := rest.ReadResponseHeader()
    if responseStatusCode < 0 {
        fmt.Println(rest.LastErrorText())
        rest.DisposeRest()
        authAws.DisposeAuthAws()
        return
    }

    fmt.Println("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 {
        jpgData := rest.ReadRespBodyBinary()
        if rest.LastMethodSuccess() != true {
            fmt.Println(rest.LastErrorText())
        }
        else {
            fmt.Println("Successfully received the JPG bytes..")
        }

    }
    else {
        errResponse := rest.ReadRespBodyString()
        if rest.LastMethodSuccess() != true {
            fmt.Println(rest.LastErrorText())
        }
        else {
            fmt.Println(*errResponse)
        }

    }


    rest.DisposeRest()
    authAws.DisposeAuthAws()