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Demos of various uses of the Java Mapper API

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/