At first I was trying to use Jena to parse the RDF. However, the DMOZ RDF files are not conforming to the standard, and a lot of parsing errors are generated.
I tried to convert the structure and content RDF files. At the end, I decided to look for other tools to achieve what I wanted.
The following are the tools that I used.
DMOZ Data Importer
This tool imports the RDF data from Open Directory Project (ODP) (http://rdf.dmoz.org) straight into a Microsoft SQL Server 2005 database.
Right now only the structure file is supported, and for my own use, I modified the DAL to load into MySQL.
This is a Perl script that can be used to load the content RDF into a MySQL database, perfectly what I wanted. It will first convert the structure RDF into a pipe delimited file, which will then be imported into MySQL.
I am going to use some of the categories in ODP as training data. If anyone of you have similiar experience using ODP I would really appreciate that you can share your experience.