Author: Đạt Trần

Recently, I need to upgrade my English learning app on Android to use multiple servers. Previously, I used two servers already. However, the way I manage media files caused me a lot of headache. So, I decided to switch to DigitalOcean since they have servers around the world and the pricing is good ($5 for 250GB storage and 1TB monthly transfer, which is good).

The initial problem with DigitalOcean spaces

Coming from old-school servers, I thought I can upload the files to DigitalOcean spaces using FTP and access the files directly as I usually used. However, the first problem is you cannot upload to spaces using FTP and the second problem is in order to make a file accessible to public, you need to set it permission to public. If you have one or two files, that wouldn’t be a problem.

I have more than 18,000 files.

The solutions to uploading multiple files

It turned out that DigitalOcean spaces use Amazon s3 technologies. So, in order to upload to spaces, you need to have FileZilla Pro (paid) or CyberDuck(free). I chose FileZilla Pro because it allows you to resume failed transfers while CyberDuck doesn’t allow that (or I couldn’t find where is that option).

The solution to accessing files

As my app used by thousands of people, the media files need to be accessible to all of the users. Actually, it is very easy to generate a public accessible URL for any files (they are called objects) using the aws-android-sdk. In case you need a working sample code, here it is:

public class DigitalOcean implements MediaServer {
    private static final String KEY = "YOUR_KEY";
    private static final String SECRETS = "YOUR_SECRETS";
    private String endpoint, bucketName;
    private AmazonS3Client s3Client;

    @Override
    public String getEndpoint() {
        return endpoint;
    }

    @Override
    public String getType() {
        return "s3";
    }

    public DigitalOcean(String endpoint, String bucketName) {
        this.bucketName = bucketName;
        this.endpoint = endpoint;
        AWSCredentials myCredentials = new BasicAWSCredentials(KEY, SECRETS);
        s3Client = new AmazonS3Client(myCredentials);
        s3Client.setEndpoint(this.endpoint);
    }

    public String getMediaURL(String objectPath) {
        GeneratePresignedUrlRequest request = new GeneratePresignedUrlRequest(bucketName, objectPath);
        URL objectURL = s3Client.generatePresignedUrl(request);
        return objectURL.toString();
    }
}

As you can see, I created an object to generate URL to any files(objects). For example, here is a sample space url:

The bucket name would be data-sample.

If your file, let call it song.mp3 located at /data-sample/media/song.mp3, the objectPath would be: /media/song.mp3.

If you run the method getMediaURL(), you will get the path to the file that is accessible to your users but you don’t have to mark the file public.

https://data-sample.sgp1.digitaloceanspaces.com/media/song.mp3?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20180925T060309Z&X-Amz-SignedHeaders=host&X-Amz-Expires=899&X-Amz-Credential=BP5K25LRRQWYV2CMHZLL%2F20180925%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=6a21133ced60047cfba60053afcdf712997c474585ade2f0050bc853b0a4db89