Chapter 12. Effectively integrating EJB 3 across your application tiers
This chapter covers
- Design patterns
- Accessing session beans from the web tier
- Packaging and using JPA from web applications
If you’ve made it this far, you’ve come a long way on our journey to the center of EJB 3. So far we’ve seen how to use session and message-driven beans for business logic, and how to use various facets of JPA to store and retrieve data. So what’s next, you ask?
Most enterprise applications are distributed across various tiers: presentation, application (or business logic), persistence. The names and number of tiers varies somewhat depending on the application and its runtime environment, as well as the scalability expectations it is designed to handle. Each of these tiers can utilize a number of possible frameworks, which vary radically due to their purpose and creator’s intent. Sprinkle in a few new mechanisms such as dependency injection and the whole thing can leave a developer asking, “Just how can I get all these new toys to work together?”