Writing files to the system in my GWT - Google App Engine (GAE) application

Question

I have created a GWT application and now want to deploy it outside GAE. The reason I wish to deploy outside the GAE is the Sandbox security feature of GAE, which disallows me from writing files to my system. I store my data in the form of an ontology (.owl file) under my '/war/WEB_INF' and I want the end user to be able to modify (write to / save) this file through the server.

I understand that GAE does not let me do this, but is there a paid Google Service (e.g. google apps) that would allow hosting a GWT application which would allow writing files to the system? For instance, like an add-on to GAE?

If not, what solution would you recommend to host a GWT application (that would let me write a file to the WEB-INF folder) on the web?

EDIT: I solved this by deploying the GWT project as a .war file and hosting in TomCat.

Answer 1

I'm very new to GAE, but in case you haven't looked at their experimental write/read blobstore services you can check that out here. They have a similar API for python I believe. It's ofcourse stored on the GAE blobstore and not under /war/WEB-INF/ directory but It does allow a possible solution to what you're looking for.

Also, if you're looking to run your own server (possibly on EC2 for example), then you might want to look into AppScale. But I, personally, would stay away from that as a solution because I highly doubt that AppScale performs as well as google's GAE web servers and furthermore lacks the same degree of support/development.

Answer 2

Have you ruled out something like creating an Owl Entity to hold your ontologies, and arranging for *.owl requests to be handled by using that as a key name to find and serve the corresponding Owl? That's really simple code.

Answer 3

GWT is primarily a client side technology. GAE is a server side technology. You seem to be getting GWT and GAE engine mixed up with each other. GAE can work with almost any client side technology, and GWT can connect to many different back end platforms.

Are you trying to move your back end code directly to a new platform? Are you planning on rewriting the back end for a new platform, but keep the GWT code? What is your goal for this application? To be used by you and a few friends, or by thousands of people? For free or paying customers?

If you want to move off of AppEngine, you can switch to pretty much any java hosting service that you want - anything from a tiny shared VPS up to a Amazon EC2 mini cloud of your own. I don't think google offers generic java hosting. I don't know how you have built your application's back end, but you probably used servlets, which you should be able to get working pretty much anywhere.

If you want to stay on AppEngine, you should think about whether or not you can break your owl file into smaller sections that can be stored as entities in the database.

Whichever platform you choose, if you are planning on serving more than a few people, you will need some way to prevent one giant owl file from becoming a huge bottleneck.