Notes on Apache OpenNLP

http://www.programcreek.com/2012/05/opennlp-tutorial/

http://www.nuxeo.com/blog/development/2011/01/mining-wikipedia-with-hadoop-and-pig-for-natural-language-processing/

Data Categorization using OpenNLP
http://hanishblogger.blogspot.com/2013/07/data-categorization-using-opennlp.html
http://codego.net/335719/
https://opennlp.apache.org/documentation/1.5.3/manual/opennlp.html#tools.sentdetect.training.tool
During learning phase a set of pre-labeled data is used to train the model and during testing phase a part of pre-labeled data is used to test the model. Then finally we can use that trained model to classify any data.

OpenNLP Models
http://opennlp.sourceforge.net/models-1.5/
http://www.nuxeo.com/blog/development/2011/01/mining-wikipedia-with-hadoop-and-pig-for-natural-language-processing/

how to train a classifier in opennlp?
For my part, I use directly the package MaxEnt for perform training
and predictions on a task other than the PosTagging, NER, etc.

Some informative links :
(1) http://maxent.sourceforge.net/about.html

(2) http://maxent.sourceforge.net/api/index.html