Spring框架学习[Spring具体事务处理器的实现](二)
tConnectionHolder(new ConnectionHolder(newCon), true); } //设置数据源事务对象的事务同步 txObject.getConnectionHolder().setSynchronizedWithTransaction(true); //获取数据源事务对象的数据库连接 con = txObject.getConnectionHolder().getConnection(); //根据数据连接和事务属性，获取数据库连接的事务隔离级别 Integer previousIsolationLevel = DataSourceUtils.prepareConnectionForTransaction(con, definition); //为数据源事务对象设置事务隔离级别 txObject.setPreviousIsolationLevel(previousIsolationLevel); //如果数据库连接设置了自动事务提交属性，则关闭自动提交 if (con.getAutoCommit()) { //保存数据库连接设置的自动连接到数据源事务对象中 txObject.setMustRestoreAutoCommit(true); if (logger.isDebugEnabled()) { logger.debug("Switching JDBC Connection [" + con + "] to manual commit"); } //设置数据库连接自动事务提交属性为false，即禁止自动事务提交 con.setAutoCommit(false); } //激活当前数据源事务对象的事务配置 txObject.getConnectionHolder().setTransactionActive(true); //获取事务配置的超时时长 int timeout = determineTimeout(definition); //如果事务配置的超时时长不等于事务的默认超时时长 if (timeout != TransactionDefinition.TIMEOUT_DEFAULT) { //数据源事务对象设置超时时长 txObject.getConnectionHolder().setTimeoutInSeconds(timeout); } //把当前数据库Connection和线程绑定 if (txObject.isNewConnectionHolder()) { TransactionSynchronizationManager.bindResource(getDataSource(), txObject.getConnectionHolder()); } } catch (Exception ex) { DataSourceUtils.releaseConnection(con, this.dataSource); throw new CannotCreateTransactionException("Could not open JDBC Connection for transaction", ex); } } //事务挂起 protected Object doSuspend(Object transaction) { //获取事务对象 DataSourceTran
sactionObject txObject = (DataSourceTransactionObject) transaction; //将事务对象中的ConnectionHolders设置为null txObject.setConnectionHolder(null); ConnectionHolder conHolder = (ConnectionHolder) //解除事务对象和当前线程的绑定 TransactionSynchronizationManager.unbindResource(this.dataSource); return conHolder; } //事务恢复 protected void doResume(Object transaction, Object suspendedResources) { //获取已暂停事务的ConnectionHolder ConnectionHolder conHolder = (ConnectionHolder) suspendedResources; //重新将事务对象和当前线程绑定 TransactionSynchronizationManager.bindResource(this.dataSource, conHolder); } //事务提交 protected void doCommit(DefaultTransactionStatus status) { //获取事务对象 DataSourceTransactionObject txObject = (DataSourceTransactionObject) status.getTransaction(); //通过事务对象获取数据库连接 Connection con = txObject.getConnectionHolder().getConnection(); if (status.isDebug()) { logger.debug("Committing JDBC transaction on Connection [" + con + "]"); } try { //使用数据库连接手动进行事务提交 con.commit(); } catch (SQLException ex) { throw new TransactionSystemException("Could not commit JDBC transaction", ex); } } //事务回滚 protected void doRollback(DefaultTransactionStatus status) { //获取事务对象 DataSourceTransactionObject txObject = (DataSourceTransactionObject) status.getTransaction(); //通过事务对象获取数据库连接 Connection con = txObject.getConnectionHolder().getConnection(); if (status.isDebug()) { logger.debug("Rolling back JDBC transaction on Connection [" + con + "]"); } try { //通过调用数据库连接的回滚方法完成事务回滚操作 con.rollback(); } catch (SQLException ex) { throw new TransactionSystemException("Could not roll back JDBC transaction", ex); } } //设置回滚 protected void doSetRollbackOnly(DefaultTransactionStatus status) { DataSourceTransactionObject txObject = (DataSourceTransactionObject) status.getTransaction(); if (status.isDebug()) { logger.debug("Setting JDBC transaction [" +