1. There are two areas for writing bean classes. The current user name has a name, a date and time, and a name. Datetime indicates the time when the current authentication failed 3 times. 2. Write two JSPs, one for judgment and one for submission. 3. When judging Jsp, if the verification fails, wrap the current time and user in the bean class and save it in the application, and judge it every time in the future. If you delete a bean from your application.