how to train a classifier in opennlp?

[T Vinod Gupta]

I want to build a classifier in opennlp using training data and then use it
to classify future documents. But I am unable to find documentation on how
to create such a training model? i see examples of POS, NER, etc, etc. But
not for classifier. can somebody give some pointers or help me in this
regard?

thanks