Have you tried these? for server-side (GAE) *com.google.appengine.repackaged.org.json.JSONObject.JSONObject(String arg0)* for client *com.google.gwt.json.client.JSONParser* I haven't tried japanese or chinese characters though, rather stuff like this: "Příliš žluťoučký kuň úpěl ďábělské ódy"

Blobstore crash course It’ll be best if we gave a quick refresher course on the blobstore before we begin. Here’s the standard flow for a blobstore upload: Create a new blobstore session and generate an upload URL for a form to POST to. This is done using the createUploadUrl() method of BlobstoreService. Pass a callback URL to this method. This URL is where the user will be forwarded after the upload has completed. Present an upload form to the user. The action is the URL generated in step 1. Each URL must be unique: you cannot use the same URL for multiple sessions, as this will cause an error. After the URL has uploaded the file, the user is forwarded to the callback URL in your App Engine application specified in step 1. The key of the uploaded blob, a String blob key, is passed as an URL parameter. Save this URL and pass the user to their final destination