Why use service layer?

Question

I looked at the example on http://solitarygeek.com/java/developing-a-simple-java-application-with-spring/comment-page-1#comment-1639

I\'m trying to figure out why t

Answer 1

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 that 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.

Regards, James