Java and J2EE code examples for 3-tier apps

Question

Do you know a site that offers a tutorial with sample source code for a 3-tier application (the usual data access layer, business layer and UI layer)?

The simple, readable and intuitive the source code. Best practices that are applied to the code are welcome as well.

Answer 1

Yes, have a look at the Spring MVC step by step example. It's very clear.

Answer 2

The sample application I'm aware of are the following:

• The famous Java Pet Store from Sun. In the version I've downloaded, it used a wide range of Java EE technologies, but it didn't use any modern MVC framework.
• From the Spring project you have several applications: JPetStore, Pet Clinic and more. All come with the spring download.
• The Seam framework has an Hotel Booking application
• You can also have a look at the 3 tier open source applications such as Liferay, but bare in mind that they may by very large. I'm not familiar with any that I can recommend, so please google for CRM/ERP/Protals etc. (sourceforge and freshmeat.net might be good sources as well)
• Although it is backed by a CMS and not database, Artifactory may also serve as a good example.

Hope these help.