Using service layer is a well accepted design pattern in the java community. Yes, you could straightaway use the dao implementation but what if you want to apply some business rules.

Say, you want to perform some checks before allowing a user to login into the system. Where would you put those logics? Also, service layer is the place for transaction demarcation.

It’s generally good to keep your dao layer clean and lean. I suggest you read the article “Don’t repeat the DAO”. If you follow the principles in that article, you won’t be writing any implementation for your daos.

Also, kindly notice that the scope of this blog post was to help beginners in Spring. Spring is so powerful, that you can bend it to suit your needs with powerful concepts like aop etc.

UserDao userDao = new UserDaoImpl();
Iterator users = userDao.getUsers();
while (…) {
…
}

It seems like the service layer is simply a wrapper around the DAO. Can someone give me a case where things could get messy if the service layer were removed? I just don’t see the point in having the service layer to begin with. thanks!

Its an awesome article to make me bit more knowledgeable in spring framework.Thanx for your great article.

thank you man, with the help of Spring and right now i have the basic understanding of Spring framework.

Don’t you have more tutorials on Spring,Hibernate,JSF,Junit and Integrator development.

Please help me James

@styls