Basic DAO question

[James Ward]

I know that DAO can be used as follows :
EJB > DAO > Database.
Can it be used as follows. Is this right ??:
EJB > DAO > Some other External System
Examples of external systems are like SMTP/another application.

[Rajeshwari Natarajan]

The primary reason for using the DAO pattern is to separate the business and the data access logic.
The datastore can be anything - database like Oracle, SQL Server, flat files, XML etc.

[Anonymous]

It is not like EJB -> DAO
DAO's are retrieved from a pattern introduced by Sun when i remember correct. You normally use this class for accessing data layer. CMP EJB's are a different way of accessing Data in your ressource (e.g. database).
In J2EE Applications with EJB you often use DAO's for retrieving a bigger amount of Data, cause it is faster than using EJB's.
You can get more info about the DAO Pattern here
Hope that helped
Olli
[ June 08, 2003: Message edited by: Oliver Refle ]