DTO & DAO

[Nimish Patel]

HI ,
Have a good day...

what is the advantage of DTO & DAO ?
I cant understand.

Thanks in anticipation.

Yours faithfully,
Nimish

[Scheepers de Bruin]

A DTO is basically an object to bundle other objects together in order to transport them.

E.g. A client needs to get a customer object and a shopping trolley object for that customer.

In stead of making two calls to the server, one for the customer and one for the trolley, the client makes one call. These two objects are put into a DTO object on server side and then passed to the client where both objects can be extracted from this one DTO.

DAO encapsulates database operations so that there is a uniform way of getting the database to do stuff. This data layer is therefore reusable. Another advantage of this modularity is that any frontend that knows how to use this uniform way can tap into the database.

[Ilja Preuss]

Originally posted by Scheepers de Bruin:

DAO encapsulates database operations so that there is a uniform way of getting the database to do stuff. This data layer is therefore reusable. Another advantage of this modularity is that any frontend that knows how to use this uniform way can tap into the database.

And in fact you can write DAO's that don't work on a database but on XML, flat files or a myriad of other persistence mechanisms. Your business logic doesn't even to know, you just give it a new DAO implementation to collaborate with.