cognos 8.1 configuration出错

在data access ->content manager  中配置好ORACLE数据库后，测试报：

[Validate Content Manager database connection]
1. [ ERROR ] The database connection failed.
2. [ ERROR ] Content Manager failed to start because it could not load driver "oracle.jdbc.driver.OracleDriver".

数据库信息配置的感觉没什么问题，但就是报错？？？什么原因呢？收起