RE: AS/400 JDBC Connection

For my J2EE development I have each request go through a filter (i.e.
doFilter()) and that creates a ThreadLocal instance which grabs a connection
from the Tomcat connection pool. That connection is then statically used
through out that request's calls to the DB.  As the request is leaving the
server the hibernate session is "closed" and returned to the pool.

HTH,
Aaron Bartell

Here is the code for DBConn.java
public class DBConn implements Filter {
    private static Logger logger = Logger.getLogger(DBConn.class.getName());
    private static SessionFactory sessionFactory;
    private static ThreadLocal tl = new ThreadLocal();

    static {
        try {
            sessionFactory = new
Configuration().configure().buildSessionFactory();
        } catch (HibernateException e) {
            e.printStackTrace();
        }
    }

    public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain)
            throws IOException, ServletException {
        try {
            chain.doFilter(request, response);
        } finally {
            Session s = (Session) tl.get();
            if (s != null) {
                try {
                    s.flush();
                    s.close();
                } catch (HibernateException e) {
                    e.printStackTrace();
                }
                tl.set(null);
            }
        }
    }

    public static Session sess() {
        Session s = (Session) tl.get();
        if (s == null || !s.isOpen()) {
            try {
                s = sessionFactory.openSession();
            } catch (HibernateException e) {
                e.printStackTrace();
            }
            tl.set(s);
        }
        return s;
    }

    public static void destroyThreadSession() {
        Session s = (Session) tl.get();
        if (s != null) {
            try {
                s.flush();
                s.close();
            } catch (HibernateException e) {
                e.printStackTrace();
            }
            tl.set(null);
        }
    }
    
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    public void destroy() {
    }
}


Web.xml entry:
        <!-- Hibernate data base connection filter -->
        <filter>
                <filter-name>DBConn</filter-name>
                <filter-class>com.mowyourlawn.util.DBConn</filter-class>
        </filter>