www.pudn.com > SSPP.rar > HibernateSessionFactory.java

package edu.neu.sspp.hibernate; 
 
import org.hibernate.HibernateException; 
import org.hibernate.Session; 
import org.hibernate.cfg.Configuration; 
 
/** 
 * Configures and provides access to Hibernate sessions, tied to the 
 * current thread of execution.  Follows the Thread Local Session 
 * pattern, see {@link http://hibernate.org/42.html }. 
 */ 
public class HibernateSessionFactory { 
 
    /**  
     * Location of hibernate.cfg.xml file. 
     * Location should be on the classpath as Hibernate uses   
     * #resourceAsStream style lookup for its configuration file.  
     * The default classpath location of the hibernate config file is  
     * in the default package. Use #setConfigFile() to update  
     * the location of the configuration file for the current session.    
     */ 
    private static String CONFIG_FILE_LOCATION = "/edu/neu/sspp/hibernate/hibernate.cfg.xml"; 
	private static final ThreadLocal threadLocal = new ThreadLocal(); 
    private  static Configuration configuration = new Configuration(); 
    private static org.hibernate.SessionFactory sessionFactory; 
    private static String configFile = CONFIG_FILE_LOCATION; 
 
    private HibernateSessionFactory() { 
    } 
	 
	/** 
     * Returns the ThreadLocal Session instance.  Lazy initialize 
     * the SessionFactory if needed. 
     * 
     *  @return Session 
     *  @throws HibernateException 
     */ 
    public static Session getSession() throws HibernateException { 
        Session session = (Session) threadLocal.get(); 
 
		if (session == null || !session.isOpen()) { 
			if (sessionFactory == null) { 
				rebuildSessionFactory(); 
			} 
			session = (sessionFactory != null) ? sessionFactory.openSession() 
					: null; 
			threadLocal.set(session); 
		} 
 
        return session; 
    } 
 
	/** 
     *  Rebuild hibernate session factory 
     * 
     */ 
	public static void rebuildSessionFactory() { 
		try { 
			configuration.configure(configFile); 
			sessionFactory = configuration.buildSessionFactory(); 
		} catch (Exception e) { 
			System.err 
					.println("%%%% Error Creating SessionFactory %%%%"); 
			e.printStackTrace(); 
		} 
	} 
 
	/** 
     *  Close the single hibernate session instance. 
     * 
     *  @throws HibernateException 
     */ 
    public static void closeSession() throws HibernateException { 
        Session session = (Session) threadLocal.get(); 
        threadLocal.set(null); 
 
        if (session != null) { 
            session.close(); 
        } 
    } 
 
	/** 
     *  return session factory 
     * 
     */ 
	public static org.hibernate.SessionFactory getSessionFactory() { 
		return sessionFactory; 
	} 
 
	/** 
     *  return session factory 
     * 
     *	session factory will be rebuilded in the next call 
     */ 
	public static void setConfigFile(String configFile) { 
		HibernateSessionFactory.configFile = configFile; 
		sessionFactory = null; 
	} 
 
	/** 
     *  return hibernate configuration 
     * 
     */ 
	public static Configuration getConfiguration() { 
		return configuration; 
	} 
 
}