What types of relationships do you feel EJB 2.0 can't adequately support? I
have been studying 2.0 CMP carefully, and it seems to be quite powerfull.
There may be holes in it, but it can handle the majority of real works
cases.
Jim
--On Friday, October 20, 2000 12:28 PM -0700 [EMAIL PROTECTED] wrote:
> If you don't use an object-relational mapping tool you're still in for a
> lot of hurt with EJB if you have a complex data model. I don't think CMP
> really addresses the kind of data models large systems have. Nor does the
> relationship support in EJB 2.0 either. I think you'll end up doing JDBC
> BMP with your Session and Entity beans. Performance is only an issue when
> you make everything a stateful session bean or an entity bean. There are
> rules for when it's appropriate to make things entity beans. There still
> isn't a whole lot of useful information around on design EJBs yet though
> with most of it only explaining the basics including the ORA book.
>
> On Fri, 20 Oct 2000, Duffey, Kevin wrote:
>
>> Thanks.
>>
>> I only meant to use the /classes folder because my ejb code is in the
>> same project as the rest of my code (Servlets, javabeans, action
>> classes, etc). Since it all compiles to the same one folder, I assume I
>> will have to "move" the ejb compiled classes every time I compile them.
>> What I was hoping for was a way to not have to do this..instead, just
>> let the whole project compile to the WEB-INF/classes folder (all my
>> code), and then have Orion pick up on the ejb changes from that point.
>> It appears to me from what everyone is saying I will have to use some
>> sort of script every time I make a change to an ejb, which my first
>> thoughts is a pain in the ass. Its very easy to develop servlets, action
>> classes, javabeans, core classes, but ejb not only requires 3 classes
>> per component, but lots of "special" work just to get the thing
>> deployed. Then, every time you make a change, it requires the same
>> process. I would think turn-around time for ejb development is on the
>> order of a couple of minutes for every change you make. That results in
>> a lot slower development cycle than I am currently using.
>>
>> Worse, I have started hearing alot of people turn away from ejb and going
>> back to servlets because of development time, and performance. Supposedly
>> the ejb stuff isn't living up to all the hype. However, I look at what
>> the ejb container does for you (connection pooling, transactions,
>> security, instance pooling, etc) and it seems there is alot of stuff I
>> wont have to do on the side of persistence, transactions and
>> security..so maybe the extra time is worth it? ;)
>>
>> Anyways..I did as one person suggested in this list, I set up in my
>> application.xml like so:
>>
>> <module>
>> <ejb>/path/www/WEB-INF/classes/</ejb>
>> </module>
>>
>> and Orion seems to be finding the classes (the ejb). However, I keep
>> seeing an error appear. It says something like:
>>
>> Error compiling class c:/path/www/WEB-INF/classes/ Login.java
>> LoginBean.java LoginHome.java can't find method create()in
>> LoginBean.java
>>
>> Its a very strange message to me. If I change the <module> path, it
>> tells me it can't find the classes. If I delete the classes, it also
>> tells me it can't find them. So I assume the path is set correctly in
>> the module <ejb> tag..as it is finding the classes. I am just not sure
>> why the heck its giving me some compiler error..or why its even trying
>> to compile them..they are already compiled.
>>
>> Anyways..I'll keep plugging away.
>>
>>
>> > -----Original Message-----
>> > From: Stanislav Maximov [mailto:[EMAIL PROTECTED]]
>> > Sent: Thursday, October 19, 2000 6:34 PM
>> > To: Orion-Interest
>> > Subject: RE: EJB Help..
>> >
>> >
>> > Kevin,
>> > look inside the news-application example bundled with Orion,
>> > lots of things
>> > will become clear for you after that.
>> > <www-dir>/WEB-INF/classes directory is for servlet classes,
>> > not for EJBs.
>> > You'll see how to deploy EJBs in that example and in
>> > documentation as well.
>> >
>> > stas@
>> >
>> > > -----Original Message-----
>> > > From: [EMAIL PROTECTED]
>> > > [mailto:[EMAIL PROTECTED]]On Behalf Of
>> > Duffey, Kevin
>> > > Sent: Friday, October 20, 2000 3:45 AM
>> > > To: Orion-Interest
>> > > Subject: RE: EJB Help..
>> > >
>> > >
>> > > Thanks for the note. One thing..since I compile all of my
>> > classes into the
>> > > www/WEB-INF/classes dir, should I put a META-INF in the
>> > /classes dir, and
>> > > just point the module to the WEB-INF/classes folder? Would
>> > that work?
>> > >
>> > > Not that I want you to tell me everything, ok..I do, but
>> > what exactly do I
>> > > need to get EJB deployed in that way? My first stab that I
>> > want to do is
>> > > create a login process. I would like to use statless session
>> > > beans, and also
>> > > use an entity bean..using CMP. I created 3 classes, Login,
>> > LoginBean and
>> > > LoginHome. I have them in com.mycompany.ejb package. That
>> > compiles to
>> > > www/WEB-INF/classes dir. So do I make application.xml like so:
>> > >
>> > > <module>/www/WEB-INF/classes</module>
>> > >
>> > > where the com folder starts? Or do I actually have to point them
>> > > directly to
>> > > the .class files themselves? If the classes are compiled in
>> > a package, I
>> > > assume I need to point the ejb module setting to the root
>> > package right?
>> > > Furthermore, do I need that ejb.xml file in META-INF? If so, what
>> > > should it
>> > > be set to if I am using an expanded dir? Lastly, how the
>> > heck to I get the
>> > > entity bean added..is that a forth class, or a whole set of
>> > 3 different
>> > > classes, one being the entity bean, the other two being
>> > like the home and
>> > > remote objects? It seems kind of silly that I would need 6
>> > > classes to do the
>> > > login process..3 for the session/logic stuff, and 3 for the
>> > > entity/database
>> > > mapping.
>> > >
>> > > Thanks so much..I appreciate the help.
>> > >
>> > >
>> > > > -----Original Message-----
>> > > > From: Mike Cannon-Brookes [mailto:[EMAIL PROTECTED]]
>> > > > Sent: Thursday, October 19, 2000 3:39 PM
>> > > > To: Orion-Interest
>> > > > Subject: RE: EJB Help..
>> > > >
>> > > >
>> > > > Kevin,
>> > > >
>> > > > With any *ar file in Orion, you can use a directory instead.
>> > > >
>> > > > eg
>> > > > <module>
>> > > > <ejb>./myejbs.jar</ejb>
>> > > > </module>
>> > > >
>> > > > can just be
>> > > >
>> > > > <module>
>> > > > <ejb>./myejbs</ejb>
>> > > > </module>
>> > > >
>> > > > where ./myejbs is a directory structure which has the
>> > same structure
>> > > > (META-INF directories etc) as inside the myejbs.jar
>> > > >
>> > > > Mike
>> > > >
>> > > > -----Original Message-----
>> > > > From: [EMAIL PROTECTED]
>> > > > [mailto:[EMAIL PROTECTED]]On Behalf Of
>> > > > Duffey, Kevin
>> > > > Sent: Friday, October 20, 2000 5:37 AM
>> > > > To: Orion-Interest
>> > > > Subject: EJB Help..
>> > > >
>> > > >
>> > > > Hi all,
>> > > >
>> > > > I am trying my hand at EJB with Orion, and I am wondering if
>> > > > there is any
>> > > > way to avoid the hassle of always having to package the ejb
>> > > > classes into a
>> > > > .jar file, and so on. Is there any way at all to develop and
>> > > > deploy ejbs
>> > > > using an expanded dir structure, much like in the development
>> > > > of a .war
>> > > > file..where you have the whole www dir, WEB-INF, etc
>> > > > expanded..but then jar
>> > > > it up and rename it to .war for deployment? It seems rather
>> > > > tedious on ejb
>> > > > development every time a change is made, the whole thing has to be
>> > > > repackaged and deployed. I know there are some tools, such as
>> > > > JBuilder,
>> > > > VisualCafe, etc that do this for you somewhat nicely..but
>> > > > even those take a
>> > > > little bit of time to do it. So, for the purposes of
>> > > > development, where many
>> > > > changes are happening on any regular basis, how can I quickly
>> > > > develop and
>> > > > test ejb, with Orion, or any app server for that matter.
>> > I do want the
>> > > > ability for the context.lookup() call to work. The reason
>> > > > is..I have two
>> > > > computers, networked. I want to develop the ejbs on one
>> > > > computer, and have
>> > > > my www stuff on the other hitting them over the network so
>> > > > that i can get
>> > > > some kind of feel of the performance. I have a 4-way
>> > switch, so I can
>> > > > develop www stuff, then switch over to the other computer and
>> > > > do some ejb
>> > > > stuff. I will run one instance of Orion on each computer.
>> > > > However, I don't
>> > > > mind also being able to run www and ejb stuff in the same on
>> > > > instance on one
>> > > > computer, as long as the lookup stuff is used the same way,
>> > > > even though the
>> > > > ejb's are running locally.
>> > > >
>> > > > Any pointers on how to set up Orion to do this, including the
>> > > > application.xml <module> tag (how to point it to the right
>> > > > place instead of
>> > > > the ejb.jar file, for example so that the ejbs will get
>> > > > picked up by the
>> > > > server), web.xml, orion-web.xml, server.xml, etc..anything
>> > > > that needs to be
>> > > > done to get this to work.
>> > > >
>> > > > Thanks so much for any help.
>> > > >
>> > > >
>> > >
>> >
>>
>
