To find the Lag of consumer offset using kafka client library

[Gourab Chowdhury]

I can get the *Lag* of offsets with the following command:-

bin/kafka-run-class.sh kafka.admin.ConsumerGroupCommand --zookeeper
localhost:2182 --describe --group DemoConsumer

I am trying to find code that uses kafka library to find the *Lag* of
offsets in consumer?

Also is there any other documentation other than https://github.com/apache/
kafka/tree/trunk/docs? I can't find much documentation of kafka.

Thanks,
Gourab Chowdhury,
Software Engg. JunctionTV Inc.