Question: Also I want to know how to add meta data while indexing so that i can boost some parameters

Answer: 
Lucene indexes text not files - you'll need some other process for extracting the text out of the file and running Lucene over that.
see <https://github.com/WolfgangFahl/pdfindexer>
for a java solution that uses PDFBox and Apache Lucene to split the PDF files page by page to text,
index these text-pages and create a resulting html index file that links to the pages in the pdf sources by using a corresponding open parameter.