用MYSQL中的加密函数来加密：PASSWORD（）

加密：<sql:update var="user" dataSource="${bookdev}">

  insert into user values("","${param.userName}",password("${param.userPwd}"),"${param.userLevel}")

</sql:update>

解密：<sql:query var="query" dataSource="${bookdev}">

  select * from user where userName='${param.userName}' and

  userPwd=password('${param.userPwd}')

</sql:query>