(Java) (using AWS Signature Version 2) Streaming Download to File

The main purpose of this example is to demonstrate how to use the older Signature Version 2 authentication w/ S3. It uses V2 authentication to download a file.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkRest rest = new CkRest();

    // Connect to the Amazon AWS REST server.
    boolean bTls = true;
    int port = 443;
    boolean bAutoReconnect = true;
    // The file is located in the bucket named "chilkat100", which becomes part of the domain:
    boolean success = rest.Connect("chilkat100.s3.amazonaws.com",port,bTls,bAutoReconnect);

    // Provide AWS credentials for the REST call.
    CkAuthAws authAws = new CkAuthAws();
    authAws.put_AccessKey("AWS_ACCESS_KEY");
    authAws.put_SecretKey("AWS_SECRET_KEY");
    authAws.put_ServiceName("s3");

    // For AWS Signature Version 2, the following two properties need to be set:
    authAws.put_SignatureVersion(2);
    // See http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html#ConstructingTheCanonicalizedResourceElement
    authAws.put_CanonicalizedResourceV2("/chilkat100/starfish.jpg");

    success = rest.SetAuthAws(authAws);

    // Send the request to download the JPG.
    success = rest.SendReqNoBody("GET","/starfish.jpg");
    if (success != true) {
        System.out.println(rest.lastErrorText());
        return;
        }

    // Read the response header.
    int responseStatusCode = rest.ReadResponseHeader();
    if (responseStatusCode < 0) {
        System.out.println(rest.lastErrorText());
        return;
        }

    System.out.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) {

        CkStream bodyStream = new CkStream();

        // The stream's sink will be a file.
        bodyStream.put_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(bodyStream,true);
        if (success != true) {
            System.out.println(rest.lastErrorText());
            return;
            }

        System.out.println("Successfully received the JPG file.");

        }
    else {
        String errResponse = rest.readRespBodyString();
        if (rest.get_LastMethodSuccess() != true) {
            System.out.println(rest.lastErrorText());
            }
        else {
            System.out.println(errResponse);
            }

        }
  }
}