MySQL的事务、JDBC事务操作：
详细见这篇文章：比较详细
http://www.cnblogs.com/xuyiqing/p/8430214.html
如何在hibernate中配置隔离级别：
再核心配置文件中：
????????<!-- 指定hibernate操作数据库时的隔离级别 ????????????#hibernate.connection.isolation 1|2|4|8 ???????????????????0001 ???1 ???读未提交 ???????????0010 ???2 ???读已提交 ???????????0100 ???4 ???可重复读 ???????????1000 ???8 ???串行化 ????????--> ????????<property name="hibernate.connection.isolation">4</property> ???????????????
这里是二进制，转换成十进制就是1，2，4，8
项目中管理事务：
没有学习hibernate框架以前，在项目中，开启事务在业务层（service），执行之后提交或回滚
而在hibernate框架中，也是这样，操作数据库需要用到的session对象，一定保证，service层和dao层的session是同一个
类似servlet项目中需要确保service层和dao层的connection对象一致，当时用到了绑定线程
（这是以前sevlet项目中的一个工具类，可以浏览下对比）
package utils;import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import javax.sql.DataSource;import com.mchange.v2.c3p0.ComboPooledDataSource;public class DataSourceUtils { ???private static DataSource dataSource = new ComboPooledDataSource(); ???private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>(); ???// 直接可以获取一个连接池 ???public static DataSource getDataSource() { ???????return dataSource; ???} ???// 获取连接对象 ???public static Connection getConnection() throws SQLException { ???????Connection con = tl.get(); ???????if (con == null) { ???????????con = dataSource.getConnection(); ???????????tl.set(con); ???????} ???????return con; ???} ???// 开启事务 ???public static void startTransaction() throws SQLException { ???????Connection con = getConnection(); ???????if (con != null) { ???????????con.setAutoCommit(false); ???????} ???} ???// 事务回滚 ???public static void rollback() throws SQLException { ???????Connection con = getConnection(); ???????if (con != null) { ???????????con.rollback(); ???????} ???} ???// 提交并且 关闭资源及从ThreadLocall中释放 ???public static void commitAndRelease() throws SQLException { ???????Connection con = getConnection(); ???????if (con != null) { ???????????con.commit(); // 事务提交 ???????????con.close();// 关闭资源 ???????????tl.remove();// 从线程绑定中移除 ???????} ???} ???// 关闭资源方法 ???public static void closeConnection() throws SQLException { ???????Connection con = getConnection(); ???????if (con != null) { ???????????con.close(); ???????} ???} ???public static void closeStatement(Statement st) throws SQLException { ???????if (st != null) { ???????????st.close(); ???????} ???} ???public static void closeResultSet(ResultSet rs) throws SQLException { ???????if (rs != null) { ???????????rs.close(); ???????} ???}}在hibernate框架中，原理是一样的，绑定线程
但是，只需要在核心配置文件中配置：
????????<!-- 指定session与当前线程绑定 --> ????????<property name="hibernate.current_session_context_class">thread</property>
代码只需一行：
???????????????SessionFactory sf = new Configuration().configure().buildSessionFactory(); ???????????????sf.getCurrentSession();
简单的测试即可理解：
package demo;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.junit.Test;import utils.HibernateUtils;//测试getCurrentSessionpublic class Demo { ???@Test ???//返回同一个与线程绑定的session ???public void fun1(){ ???????Session session1 = HibernateUtils.getCurrentSession(); ???????Session session2 = HibernateUtils.getCurrentSession(); ???????????????System.out.println(session1==session2);//true ???} ???????@Test ???//返回不同的session ???public void fun2(){ ???????Session session1 = HibernateUtils.openSession(); ???????Session session2 = HibernateUtils.openSession(); ???????????????System.out.println(session1==session2);//false ???} ???????}补上工具类:
package utils;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;public class HibernateUtils { ???private static SessionFactory sf; ???????static{ ???????//1 创建,调用空参构造 ???????Configuration conf = new Configuration().configure(); ???????//2 根据配置信息,创建 SessionFactory对象 ????????sf = conf.buildSessionFactory(); ???} ???????//获得session => 获得全新session ???public static Session openSession(){ ???????????????//3 获得session ???????????????Session session = sf.openSession(); ???????????????????????????????return session; ???????????} ???//获得session => 获得与线程绑定的session ???public static Session getCurrentSession(){ ???????//3 获得session ???????Session session = sf.getCurrentSession(); ???????????????return session; ???} ???}注意：
通过getCurrentSession方法获得的session对象，事务提交时候，会自动关闭session，不要手动关闭，否则会有异常
hibernate框架学习笔记6：事务
原文地址：https://www.cnblogs.com/xuyiqing/p/8449167.html