使用 HibernateSessionFactory 类

复制 HibernateSessionFactory.java 到 util 包下

package util;

import org.hibernate.HibernateException;
import org.hibernate.cfg.Configuration;
import org.hibernate.classic.Session;

public class HibernateSessionFactory {

	private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";
	// 给线程绑定一个Session 比类级别更加安全
	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;

	// 运行一次 先于类构造方法完成 内存寄存器位置
	static {
		try {
			configuration.configure(configFile);
			sessionFactory = configuration.buildSessionFactory();
		} catch (Exception e) {
			System.err.println("%%%% Error Creating SessionFactory %%%%");
			e.printStackTrace();
		}
	}

	private HibernateSessionFactory() {
	}

	// 获得连接
	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;
	}
	public static void rebuildSessionFactory() {
		try {
			configuration.configure(configFile);
			sessionFactory = configuration.buildSessionFactory();
		} catch (Exception e) {
			System.err.println("%%%% Error Creating SessionFactory %%%%");
			e.printStackTrace();
		}
	}

	// 关闭资源
	public static void closeSession() throws HibernateException {
		Session session = (Session) threadLocal.get();
		threadLocal.set(null);

		if (session != null) {
			session.close();
		}
	}
	public static org.hibernate.SessionFactory getSessionFactory() {
		return sessionFactory;
	}
	public static void setConfigFile(String configFile) {
		HibernateSessionFactory.configFile = configFile;
		sessionFactory = null;
	}
	public static Configuration getConfiguration() {
		return configuration;
	}

}

实例化该类

Session session = HibernateSessionFactory.getSession();

释放资源操作

HibernateSessionFactory.closeSession();

PS：实例化 HibernateSessionFactory 类，就可以使用了，使用完后，就需要释放资源，关闭Session。

例子：

package test;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;

import util.HibernateSessionFactory;

import entity.Student;
import entity.Teacher;

public class MaryToOneTest2 {
	public static void main(String[] args) {
		maryToOne();
	}

	private static void maryToOne() {
		
		Session session = HibernateSessionFactory.getSession();
		// 增删改用事务
		Transaction tx = null;
		
		Teacher teacher =new Teacher("李老师");
		Student student1 = new Student("A学生");
		Student student2 = new Student("B学生");
		
		try {
			tx=session.beginTransaction();
			session.save(teacher);
			session.save(student1);
			session.save(student2);
			tx.commit();
			System.out.println("保存成功!!!");
		} catch (HibernateException e) {
			e.printStackTrace();
			tx.rollback();
		}finally{
			HibernateSessionFactory.closeSession();
		}
	}
}

效果图：