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<h2 class="first-section-title"><a name="472"></a><a name="ch14lev1sec4"></a>Architect's Exercise: ProjectTrak</h2><p class="first-para">In the <a href="LiB0089.html#429" target="_parent" class="chapterjump">previous chapter</a>, we identified four business objects that provide functionality for a Web-compliant Java/J2EE presentation tier. At this point, the use cases don't require interfacing with additional clients or legacy systems. All processing identified is synchronous. Because this is intended as an enterprise-wide product, we would like to keep clustering technology capabilities for high availability.</p>
<p class="para">Session beans are the J2EE deployment mechanism that meets these requirements. Neither Web services nor CORBA are required because we haven't identified a need to support non-J2EE platforms. Should this need come up in the future, we can add a deployment for it relatively easily. RMI services don't satisfy typical availability requirements for this kind of <a name="473"></a><a name="IDX-196"></a>application. And we don't require asynchronous processing or interfaces to legacy applications, so we don't need messaging technologies, such as JMS.</p>
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<p class="para">Given all of this, we'll deploy our business objects as session beans for the time being. With our layered architecture, we can add deployments or swap out our session beans for something else down the line if we need to.</p>
<p class="para">I've adopted the shortcut discussed in <a href="LiB0030.html#129" target="_parent" class="chapterjump">chapter 5</a> of modeling the beans as one object. Each enterprise bean object in the model should be understood to contain a stateless session bean, a controller, a controller home, and a client stub. <a class="internaljump" href="#ch14fig03">Figure 14.3</a> illustrates a more complete model for the <span class="fixed">ProjectBean</span>, without that shortcut.</p>
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<a name="475"></a><a name="ch14fig03"></a><span class="figuremediaobject"><a href="images/fig212%5F01%5F0%2Ejpg" NAME="IMG_41" target="_parent"><img src="images/fig212_01.jpg" height="214" width="350" alt="Click To expand" border="0"></a></span>
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<span class="figure-title"><span class="figure-titlelabel">Figure 14.3: </span>Complete Object Model of the ProjectBean</span>
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