There is not possible to get fully prepared document before it is sent to index.

My proposition is to add param to ClassBridge definition witch define calling time:

• Before - before document build (current way)
• After - after document build (new way)

Initially described here:
http://stackoverflow.com/questions/16673246/how-to-get-org-apache-lucene-document-document-after-fully-builded-but-before-in