Appending to index

[Nitasha Walia (niwalia)]

Hi,
 
I am a new user of Java Lucene. The default index is such that a new
files is created every time, which requires me to delete the existing
index folder. 
 
I want to append to the existing index. Can someone please guide me on
how to do the same?
 
Thanks,
Nitasha Walia
Software Engineer, Cisco Systems