Java

Generate an AWS (S3) Pre-Signed URL to Download File

See more Amazon S3 (new) Examples

Demonstrates how to generate a pre-signed URL to download a file from the Amazon S3 service. Java

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[])
  {
    boolean success = false;

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

    CkHttp http = new CkHttp();

    http.put_AwsAccessKey("AWS_ACCESS_KEY");
    http.put_AwsSecretKey("AWS_SECRET_KEY");

    // Make sure to set your AWS region correctly
    http.put_AwsRegion("us-east-1");

    String bucketName = "chilkat100";
    String objectName = "starfish/starfish.jpg";
    String localFilePath = "qa_output/starfish.jpg";
    String awsService = "s3";

    // The signed URL will be valid for this number of seconds:
    int numSecondsValid = 86400;

    // Choose between a URL beginning with "http://" or "https://"...
    boolean bUseHttps = false;

    // Generate the pre-signed URL
    String preSignedUrl = http.s3_GenPresignedUrl("GET",bUseHttps,bucketName,objectName,numSecondsValid,awsService);
    if (http.get_LastMethodSuccess() == false) {
        System.out.println(http.lastErrorText());
        return;
        }

    // The following URL can be copy-and-pasted into a browser..
    System.out.println("Pre-Signed AWS S3 URL: " + preSignedUrl);

    // Here's an example of a pre-signed URL. 
    // This URL will only work within 1 day (86400 seconds) after the time this example was published.
    // 
    //     http://chilkat100.s3.amazonaws.com/starfish/starfish.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=16QXXDGY83AJJR6RVQ02%2F20170111%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Date=20170111T161959Z&X-Amz-Expires=86400&X-Amz-SignedHeaders=host&X-Amz-Signature=72bf4fd9a15d7bbcdd313a3318d937a778905f62a3fbff9b789d8dc28acd9232

    // Now try to do an HTTP Download using the signed URL.
    success = http.Download(preSignedUrl,"c:/temp/qa_output/starfish.jpg");
    if (success == false) {
        System.out.println(http.lastErrorText());
        return;
        }

    System.out.println("Success.");
  }
}