Tool Support for Entity Beans

Entity beans don't usually contain business logic, so they're good candidates for auto-generation. This is just as well, as entity beans tend to contain a lot of code - for example in getter and setter methods. The deployment descriptors for EJB 2.0 CMP entities are also far too complex to hand-author reliably.

Good tool support is vital to productivity if using entity beans. Several types of tools are available, from third parties and application server vendors. For example:

  • Object modeling tools such as Rational Rose and Together. These use the object-driven modeling approach we discussed in Chapter 7, enabling us to design entities graphically using UML and generate RDBMS tables. This is convenient, but object-driven modeling can create problems.

  • Tools to generate entity beans from RDBMSs. For example, Persistence PowerTier supports this kind of modeling.

  • Tools to generate entity bean artifacts from a simpler, easier-to-author, representation. For example, both EJBGen and XDoclet can generate local and home interfaces, J2EE standard and application-server-specific deployment descriptors from special Javadoc tags in an entity bean implementation class. Such simple tools are powerful and extensible, and far preferable to hand-coding.

Important 

There is a strong case that entity beans should never be hand authored. One argument in favor of using entity beans is the relatively good level of tool support for entity bean authoring.



Expert One-on-One J2EE Design and Development
Microsoft Office PowerPoint 2007 On Demand
ISBN: B0085SG5O4
EAN: 2147483647
Year: 2005
Pages: 183

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