分布式事务

注解：  @GlobalTransactional   手写：

GlobalTransaction tx = GlobalTransactionContext.getCurrentOrCreate();

        try {
            tx.begin();
            tx.commit();//不能提交
        }catch (Exception e){
            log.error("下单失败");
            try{
                tx.rollback();
            } catch (TransactionException ex) {
                log.info("回滚失败");
            }

        }