Hi guys, first of all, sorry I'm a GAE noob so there are lots of things that I need specific answers. My problem is that I have successfully created a servlet that allows the app users to upload their files. Basically, I created an entity with a Blob attribute to store the file's contents. The uploaded file is made persistent in the datastore with a primary key. Now I'm wondering how to let the users retrieve their files knowing the keys. In other words, I'd like display the file contents (image, video, etc.) upon user's request.
My solution basically follows this http://stackoverflow.com/questions/1513603/how-to-upload-and-store-an-image-with-google-app-engine-java. But there I don't know how to invoke the method for retrieval? How to config the servlet and how to invoke it? As in uploading, you have the method FormPanel.submit() and the corresponding doPost() method in the servlet, eg.
Some people have suggested using Blobstore, but as far as I know, it is a paid service and at the moment I prefer keeping my app billing-free. ;-)