HI I got the null pointer exception using session factory

Exception in thread "main" java.lang.NullPointerException
at mypack.Hibernate_Test.main(Hibernate_Test.java:71)
Inserting Record

HI I got those above exception while using this below code.

package mypack;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;
import mypack.Details;
import org.hibernate.HibernateException;
public class Hibernate_Test 
{
private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";
 
    /** Holds a single instance of Session */
private static final ThreadLocal threadLocal = new ThreadLocal();
 
    /** The single instance of hibernate configuration */
    private static final Configuration cfg = new Configuration();
 
    /** The single instance of hibernate SessionFactory */
    private static org.hibernate.SessionFactory sessionFactory;
 
    public static Session sn;
public static Session currentSession() throws HibernateException 
{
        Session session = (Session) threadLocal.get();
 
if (session == null || !session.isOpen()) 
{
if (sessionFactory == null) 
{
try
{
//cfg.configure(CONFIG_FILE_LOCATION);
sessionFactory = cfg.configure(CONFIG_FILE_LOCATION).buildSessionFactory();
}
catch (Exception e) 
{
System.err.println("%%%% Error Creating SessionFactory %%%%");
e.printStackTrace();
}
}
session = (sessionFactory != null) ? sessionFactory.openSession(): null;
threadLocal.set(session);
}
 
        return session;
    }
public static void main(String[] args) 
{
   try
{

//System.out.println(session.toString());
//Create new instance of Details and set values in it by reading them from form object
 System.out.println("Inserting Record");
 sn=currentSession();
 Details details = new Details();
details.setId(6);
details.setName("Deepak");
details.setCity("Delhip");
details.setAge(20);

sn.save(details);
System.out.println("Done");
}
catch(Exception ex)
{
System.out.println(ex.getMessage());
}
finally
{
//System.out.println(session.toString());
// Actual contact insertion will happen at this step
sn.flush();
sn.close();
}

}
 
}

[ Edited to use code tags - Paul Sturrock ]
[ October 12, 2008: Message edited by: Paul Sturrock ]

What happens at line 71? What errors (if any) is Hibernate logging?

I Solved my exception by adding hibernate 3.0 advanced library to my project
but the output is
id=0
name=null
city=null
age=0
that is not correct,so what i do for getting correct value from database?
A table has four field
ID number
name varchar2(20)
city varchar2(15)
age number
in oracle database
please reply this...
Thankyou

What output? Your application only seems to print out exception messages and the word "Done". Please explain the details.