请教hibernateSessionFactory 二次加载问题

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请教hibernateSessionFactory 二次加载问题10

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 = "/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 <code>SessionFactory</code> 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;
	}

}

以上HibernateSessionFactory代码由MyEclipse自动生成。
tomcat刚刚启动后，在登录界面首次初始化HibernateSessionFactory时连续点击两次登录对HibernateSessionFactory加载两次会报Duplicate class/entity mapping异常。
请教大家这个错误如何解决？万分感谢！
问题补充：

public synchronized static void rebuildSessionFactory() {    
        if(sessionFactory != null) return;   
        try {      
            configuration.configure(configFile);      
            sessionFactory = configuration.buildSessionFactory();      
        } catch (Exception e) {      
            System.err      
                    .println("%%%% Error Creating SessionFactory %%%%");      
            e.printStackTrace();      
        }      
    }

以上试过了，还是无法解决！

Hibernate

2008年6月18日 11:46

lgcpeter
95
0 0 0

1个答案按时间排序按投票排序

0 0

可以将rebuildSessionFactory方法同步掉，这样返回的sessionFactory就是单例

public synchronized static void rebuildSessionFactory() { 
    	if(sessionFactory != null) return;
        try {   
            configuration.configure(configFile);   
            sessionFactory = configuration.buildSessionFactory();   
        } catch (Exception e) {   
            System.err   
                    .println("%%%% Error Creating SessionFactory %%%%");   
            e.printStackTrace();   
        }   
    }

2008年6月18日 12:47