??????????????????????if there are more than two server run with the same system code
??????????? and call the save method at the same time ,it will be result of hibernate
??????????? error!because hibernate get the max id for ganerator and store it in
??????????? cache for next time using.so one server will get the expired id if another
??????????? server change the database following.
??????????? befroe save object,hibernate will excute this sql after the server start up once:
???????????? Hibernate: select max(ID) from TB_LOG
??????????? TB_LOG is my log table.