Introduction - If you have any usage issues, please Google them yourself
Used in multi-threaded JAVA sample bank teller problem. Have an account, bank cards, passbooks three classes, when a user exceeds the amount of bank card withdrawals when the balance is displayed " insufficient funds" and the remaining amount of bank card number. Display information: the amount you get 1,000 yuan! Sorry, insufficient funds! Balance of 200 yuan! Balance of 200 yuan!