数据库应用，在许多软件系统中经常用到，是开发中大型系统不可缺少的辅助。但如果对数据库资源没有很好地管理(如：没有及时回收数据库的游标(ResultSet)、Statement、连接 (Connection)等资源)，往往会直接导致系统的稳定。这类不稳定因素，不单单由数据库或者系统本身一方引起，只有系统正式使用后，随着流量、用户的增加，才会逐步显露。 -database applications, in many software systems often used, is developing large systems indispensable aids. But if the right database resources are not well managed (eg : no timely recovery database cursor (ResultSet), the Statement connect (Connection), and other resources), will often lead directly to the stability of this system. Such factors of instability, not only by the database system itself or caused side, the official use only, as the flow of users increases, will gradually revealed.