java问题

问题：java.lang.IllegalStateException: 非法访问：此Web应用程序实例已停止。无法加载[com.mysql.jdbc.ExportControlled]

添加监听器：

public void contextDestroyed(ServletContextEvent sce) {
        try {
            System.out.println("Servlet销毁");
//            SqlConnection.dbDestroyed();
            Enumeration drivers = DriverManager.getDrivers();
            while (drivers.hasMoreElements()) {
                Driver driver = (Driver) drivers.nextElement();
                DriverManager.deregisterDriver(driver);
                System.out.println("deregistering jdbc driver: " + driver);
            }
            AbandonedConnectionCleanupThread.uncheckedShutdown();
        }catch (Exception e){
            e.printStackTrace();
            System.out.println("销毁工作异常");
        }
    }