I have a project which uses Google App Engine Java.
I need all of the data taken from my table in the form of
SID (String - key) Data (blob : Java object)
I have code which gets a string from the blob data, so your job will simply be to use task queues or something of the sort to iterate through each database entry and output the SID and Data to a file in a format I can parse.
For example the output could be in JSON
["sid":"SID_3049", "data":"data from 3049"]
As long as its parser friendly, we're great!
If you know how to use GAE with Java, this will be easy. If you don't, you may not want to bid on this. This is NOT something you can just pick up and begin doing as it is new, buggy, lacking in features, and has virtually no support.