Constructing a Solution: Servlets, JSP, and Enterprise JavaBeans
In This Chapter
In the last chapter we finally saw the fruits of our hard analysis and design efforts. We crafted a slice of our architectural prototype using a collection of components that had one requirement: not to rely on a commercial container product or use Enterprise JavaBeans. In this chapter we move forward and take the same slice of the architectural prototype created in the last chapter, add additional functionality, and implement it using Enterprise JavaBeans.
We will do things a bit differently in our approach in this chapter. In the last chapter we didn't use the benefits that a visual modeling tool has to offer code generation; in this chapter we will use a visual modeling tool to generate much of our code. But don't worry. Code generation gives us only the embryo of the code; we still have to do the hard part: filling in between the lines.
Our focus in this chapter will be to generate initial skeleton code from the class diagram that we built in Rational Rose. From there, we have to begin filling in the code to make the skeleton do something for us.
To review the mission of the visual modeling tool as it pertains to program code generation.
To review the setup issues in preparing to generate program code.
To review what to watch out for after code generation is complete.
To explore the code necessary to add additional functionality to the Maintain Relationships use-case and to implement the solution in a commercial EJB container.
Next Steps of the Elaboration Phase
Before constructing the first portion of our Remulak solution, let's revisit again the Unified Process. FIGURE 12-1 shows the process model, with the Elaboration phase highlighted.
FIGURE 12-1 Unified Process model: Elaboration phase
In this chapter we will again specifically focus on building code. This code will lead to the second attempt at an architectural prototype. The architectural prototype will be complete at the end of this chapter. At that point the architecture itself should also be considered complete, and we will have reached the Lifecycle Architecture milestone within the Unified Process.
Even at the end of this chapter it may seem as though we haven't reached the Construction phase as the Unified Process defines it. Remember, however, that each phase slices through all the workflows. The Implementation workflow deals with building code, and we have most definitely been building code. The focus, once the Construction phase is entered, will be to incorporate all the exception handling of every use-case as defined in each package for Remulak. All the business rules must be implemented as well. Construction is a manufacturing process that leverages what we have built in the Elaboration phase.
In the Unified Process, the following workflows and activity sets are emphasized:
Analysis and Design: Design Components
Implementation: Implement Components
The emphasis now is on testing our design strategies for how the code comes together with Enterprise JavaBeans.