Hi everyone, Aslak Helles�y asked on Monday, July 15, 2002 12:50 PM > > Hi! > > > > JSR 26 (UML/EJB Mapping Specification) defines a mapping between UML and > > EJB, basically it's defining UML extensions such as stereotypes, tagged > > values and constraints whose goals are to describe EJBs. > > > > Does UML2EJB try to comply with this specification in any way? (I'm not > > asking whether it fully complies with it, rather if any attempt > > was made to > > comply with it). I have just skimmed it, and it looks like the spec > > currently doesn't support EJB 2.0. -But the spec lead was > > bragging about it > > on TSS lately, so I guess it's still alive... > > > > http://jcp.org/aboutJava/communityprocess/review/jsr026/ > > http://www.jcp.org/jsr/detail/26.jsp > > http://www.theserverside.com/events/library.jsp (See Jack Greenfield > > interview) > > > > Regards, > > Aslak
Then, "J. Matthew Pryor" <[EMAIL PROTECTED]> said on 15.07.2002, 05:04:39: > Yes rather then creating a whole lot of new meta-data, where possible > existing specifications should be used. > > There certainly has been work on a UML profile for EJBs and this would seem > helpful to uml2ejb > > jmp Well, this is what I say: 1) No, till today, there was not made any attempt to comply with JSR-26. 2) However, UML2EJB could try to comply with about 10% of JSR-26. Why this? 1) JSR-26 was new to me. I skimmed over it today. 2) This is because JSR-26 tries to do a different thing than UML2EJB. Oops! What do I mean by "a different thing"? == What does JSR-26 do? == JSR-26 says on the title page: "The UML Profile For EJB is a mapping from the Unified Modeling Language (UML) to the Enterprise JavaBeans (EJB) architecture. The mapping specifies the standard representation for elements of the EJB architecture in UML models." In the introduction, it continues: "The UML Profile For EJB lets software designers use the UML to describe software systems based on the EJB architecture. It defines standard representations for EJB- based software artifacts in the UML, providing a basis for forward engineering artifacts from UML models and for reverse engineering UML visualizations from artifacts." The participants of the JSR-26 group go ahead and do what they say: They represent each and every element of the EJB architecture in UML. That means, home interfaces, remote interfaces, environment entries, security roles, the whole thing with bells and whistles. They express all these EJB architecture elements with associated stereotypes, carefully selected and carefully attached to the different model elements. == What does UML2EJB do? == UML2EJB follows the DTSTTWPW principle that you may know from Extreme Programming: "Do the simplest thing that will possibly work". UML2EJB is for the software designer who has just found the concept classes after careful object oriented analysis. This designer (call him Matt) now tries to represent the concepts by EJB classes, saying: "this could be an entity" or "there we need a session facade". Matt tries to model at a moderately technical level - he does not want to see home interfaces, remote interfaces, value objects, etc. Matt knows that he will need them later but he simply does not want to see them in the model. One class should still be one class, not four classes (bean, data, util, impl) and four interfaces (home. remote, local home, local)! However, Matt knows very well that he has to say which attribute of the entity should be the primary key. He also knows that he will have to say "this EJB references that EJB". So, Matt introduces as few technical elements as necessary and keeps the model readable. In the next step, Matt and his team members go ahead and handcraft the templates so that they cover the concepts that Matt has expressed as stereotypes. At last, they run UML2EJB to see if the code says what they mean. UML2EJB looks at the stereotypes and maps them to existing templates. How many classes correspond to an <<EntityBean>> is entirely dependent on the templates. How these classes form a hierarchy also depends on the templates. == So, what does all this tell us? == UML2EJB with its current template set refuses to follow the same goal as JSR-26. However, JSR-26 has (for example) a clever list of stereotypes where UML2EJB could take a subset from. JSR-26 may have much more (I do not know yet) that UML2EJB could also benefit from. I'll keep JSR-26 in mind before future versions of UML2EJB come out. Let's see a couple of users first that post their experience with UML2EJB to the list. Let's hear about their needs first. This will tell us important things. CUAGN... Matthias ---------- Matthias Bohlen Consulting that helps project teams succeed... http://www.mbohlen.de ------------------------------------------------------- This sf.net email is sponsored by: Jabber - The world's fastest growing real-time communications platform! Don't just IM. Build it in! http://www.jabber.com/osdn/xim _______________________________________________ Xdoclet-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/xdoclet-user
