This chapter has covered some of the major issues of session-bean design and implementation. We have seen that:

We've built on our knowledge of EJB container services by considering:

We've looked at the "Business Methods Interface" pattern, a simple coding technique that can prevent errors by ensuring that an EJB's component interface and implementation class are always in sync. This involves making both component interface and bean implementation class implement a "business methods interface", enabling the compiler to check that method signatures match. We've discussed the following good session bean implementation practices:

The following recommendations apply to stateful session beans:

In the next chapter we'll move on to overall app infrastructure, including some generic EJB superclasses that can simplify development and reduce the likelihood of errors when implementing session beans and message-driven beans.