Question

I’m using Google App Engine and i need to store a big file (2-20Mb). It is a text file that i convert to a JSONArray. I need to be able to add JSONObjects to this array and to be able to read it.

I wanted to use Blobs but I noticed that blobs can’t be updated(is it true??).
I don’t want to enable billing thus, I can’t use FileService(or…?).
Storing eache JSONOBject in the db explodes my reading quota.
With cache, the objects are sometimes removed.

Do you see a way to solve my problem?

Best regards!

Answer 1

This is what the blobstore is for.

https://developers.google.com/appengine/docs/java/blobstore/overview

The Blobstore API allows your application to serve data objects, called blobs, that are much larger than the size allowed for objects in the Datastore service. Blobs are useful for serving large files, such as video or image files, and for allowing users to upload large data files. Blobs are created by uploading a file through an HTTP request.

You get free quote here also.

No, you can’t change them once you have uploaded them. If you want to do that then store your data as structured data in the datastore instead. But you can delete and replace blobs.