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androidhttpurlconnectionandroid-image

How to zip multiple images and post to server using google recommended HTTPURLConnection?

How to zip multiple images and post to server using google recommended HTTPURLConnection? For example 50 images available getExternalFilesDir(Environment.DIRECTORY_PICTURES) directory,

  1. Can I use Gzip to club and compress as a single file?
  2. How many images can i club in a single file?
  3. What is the maximum size of compressed file post to server using HTTPURLConnection?
  4. Can I use Multipart HTTP request to post the compressed file?
  5. Is it any best practice available in android to post multiple images to server?
Solution
    1. Gzip compresses only streams and doesn't maintain a directory of files. You could use "java.util.zip.*" or JTar to tar the files and then Gzip. Depends on what you have server-side.
    2. This should be restricted only by bandwidth.
    3. Restrictions might exist on server-side (php.ini e.g.), not for Android
    4. Multi-Part might be a way to solve your problem. But AFAIK there is no appropriate implementation for HttpURLConnection. And it's possible that your binary files "expand" the payload by beeing transformed to Base64 encoded, 7-Bit Strings (I'm not really sure about this point).
    5. I don't know. But a very important point here is that you should transfer the images in a background service, especially when you build big chunks of data. Even AsyncTask might fall short, because lifetime might be dependent on the activity and when uploading a large amout of data the activity could already be destroyed. Have a look at RoboSpice. If you don't use the library, at least copy the strategy they use. Personally, I'd begin with binary uploading image by image, each with a new HttpURLConnection. Android will maintain an open connection (keep-alive), the traffic can be binary and the only thing you lose is some time (latency). But this would be a lot easier to implement on client-side and probably on server-side, too.