hibernate使用SessionFactory的时候用单例和JUnit里的创建方法

因为创建SessionFactory会很慢，建一次就行，用static 创建单例即可，以后用到了直接调用即可

package util;import org.hibernate.*;import org.hibernate.cfg.*;public class HibernateUtil {    private static final SessionFactory sessionFactory;    static {        try {            // Create the SessionFactory from hibernate.cfg.xml            sessionFactory = new Configuration().configure().buildSessionFactory();        } catch (Throwable ex) {            // Make sure you log the exception, as it might be swallowed            System.err.println("Initial SessionFactory creation failed." + ex);            throw new ExceptionInInitializerError(ex);        }    }    public static SessionFactory getSessionFactory() {        return sessionFactory;    }}

在JUnit中在类里可以这么写

public static SessionFactory sf = null;

@BeforeClass
public static void beforeClass(){
sf = new AnnotationConfiguration().configue().buildSessionFactory();
@Test
....类的其他内容
@AfterClass
public static void afterClass(){
sf.close();
}
}