Demonstrates a bunch of useful Mappers for use with the App Engine Mapreduce library
The Mapper library can be found here:
http://code.google.com/p/appengine-mapreduce
This project includes sample code for using the Java version of this
library. Code samples include:
- Changing all Strings to lowercase across all Entities
- Changing all Strings to lowercase across all Entities using a mutation pool (more efficient)
- Deleting all Entities of a given Kind
- Counting all the words across all Entities, then using a callback URL to save them
- Taking an input in the Mapper interface
- Importing data from a CSV file into the datastore
The introductory blog post to the Mapper API can be found here:
http://ikaisays.com/2010/07/09/using-the-java-mapper-framework-for-app-engine/
A follow up post about reading input from the Blobstore can be found here:
http://ikaisays.com/2010/07/09/using-the-java-mapper-framework-for-app-engine/