HibernateUtils.java

转载，有修改

import java.io.Serializable;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;public class HibernateUtils {    private static SessionFactory sessionFactory;    private HibernateUtils() {    }    static {        /**         * configure()参数为空默认查找classes目录下hibernate.cfg.xml         * configure("文件名")也有重载方法，参数名为配置文件名         */        sessionFactory = new Configuration().configure().buildSessionFactory();    }    public static SessionFactory getSessionFactory() {        return sessionFactory;    }    /**     * 如果想使用sessionFactory.getCurrentSession()来获得Session时，需要在配置文件中添加一句：     * <!-- 本地事务 防止使用sessionFactory.getCurrentSession()时报错："org.hibernate.HibernateException: No CurrentSessionContext configured!"-->     * <property name="hibernate.current_session_context_class">thread</property>     * @return     */    public static Session getCurrentSession() {        return sessionFactory.getCurrentSession();    }    public static Session getNewSession() {        return sessionFactory.openSession();    }    public static void add(Object entity) {        Session s = null;        Transaction tx = null;        try {            s = HibernateUtils.getNewSession();             tx = s.beginTransaction();            s.save(entity);            tx.commit();        } finally {            if (s != null) {                s.close();            }        }    }    public static void update(Object entity) {        Session s = null;        Transaction tx = null;        try {            s = HibernateUtils.getNewSession();            tx = s.beginTransaction();            s.update(entity);            tx.commit();        } finally {            if (s != null) {                s.close();            }        }    }    public static void delete(Object entity) {        Session s = null;        Transaction tx = null;        try {            s = HibernateUtils.getNewSession();            tx = s.beginTransaction();            s.delete(entity);            tx.commit();        } finally {            if (s != null) {                s.close();            }        }    }    public static Object get(Class<Object> classname, Serializable id) {        Session s = null;        try {            s = HibernateUtils.getNewSession();            Object obj = s.get(classname, id);            return obj;        } finally {            if (s != null) {                s.close();            }        }      }  }