What is the need for creating a Exception for DAO Layer

[PavanPL KalyanK]

What is the need for creating a Exception for DAO Layer like in this code below :

public List getProducts() throws DAOException 

[Jeanne Boyarsky]

To tell you something went wrong in the database layer? Can you expand on your doubt?

[PavanPL KalyanK]

Jeanne Boyarsky wrote: Can you expand on your doubt?

Jeanne thanks for the reply, My doubt is that

DAOException is a Checked or a RuntimeException ? and how the client (Servlet) should handle this ??

[Bauke Scholtz]

It is not necessarily to be called "DAOException". It is just a homegrown class which you use to hide the specific exceptions of the wrapped database communication API, like JDBC or Hibernate. If you already have the class, just check if it extends Exception or RuntimeException, then the remaining is fairly self-explaining.

Also see this article: http://balusc.blogspot.com/2008/07/dao-tutorial-data-layer.html (do not only scan the code/article, but also read the text).