C++

REST Download Binary to Memory (CkByteData) (Amazon S3)

See more Amazon S3 (new) Examples

This example demonstrates how to perform a REST call to download a binary file from Amazon S3, returning a binary response body suitable for files that fit in memory. For larger files, Chilkat offers options for streaming directly to a file or making an asynchronous call, allowing the foreground thread to read the response body stream. C++

#include <CkRest.h>
#include <CkAuthAws.h>
#include <CkByteData.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkRest rest;

    //  Connect to the Amazon AWS REST server.
    bool bTls = true;
    int port = 443;
    bool 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.
    CkAuthAws authAws;
    authAws.put_AccessKey("AWS_ACCESS_KEY");
    authAws.put_SecretKey("AWS_SECRET_KEY");
    authAws.put_ServiceName("s3");
    success = rest.SetAuthAws(authAws);

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

    //  Send the request to download the JPG.
    success = rest.SendReqNoBody("GET","/starfish.jpg");
    if (success != true) {
        std::cout << rest.lastErrorText() << "\r\n";
        return;
    }

    //  Read the response header.
    int responseStatusCode = rest.ReadResponseHeader();
    if (responseStatusCode < 0) {
        std::cout << rest.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Response status code = " << responseStatusCode << "\r\n";

    //  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) {
        CkByteData jpgData;
        success = rest.ReadRespBodyBinary(jpgData);
        if (rest.get_LastMethodSuccess() != true) {
            std::cout << rest.lastErrorText() << "\r\n";
        }
        else {
            std::cout << "Successfully received the JPG bytes.." << "\r\n";
            //  See the CkByteData online reference documentation for 
            //  information about accessing and manipulating the byte data.
        }

    }
    else {
        const char *errResponse = rest.readRespBodyString();
        if (rest.get_LastMethodSuccess() != true) {
            std::cout << rest.lastErrorText() << "\r\n";
        }
        else {
            std::cout << errResponse << "\r\n";
        }

    }
    }