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Posted to users@tomcat.apache.org by TO...@LILLY.COM on 2002/08/15 01:01:27 UTC
Enterprise Java Beans (EJB)
Hi
Does Tomcat support EJB?.....
if not, is there a project to migrate tomcat to support EJB?... it will be
a very nice feature...
Alex
Re: Enterprise Java Beans (EJB)
Posted by Ned Wolpert <wo...@codeheadsystems.com>.
> However if you find EJB's slow and not scalable, than you would
> implement DAO another way. But since you would pull out Enity beans out,
> than there is not much reason to keep Session beans. You could just put
> regular form bean or java bean in session in some cases and get rid of
> EJB server and just use TomCat or Resin. (most app. servers have other
> ways to fail over). If you have reson to use session EJBs that use them,
> but I can think of no reason anyone would want to uses Enity EJB.
Well, this isn't the best forum for this, but Entity beans have a purpose,
just the vendor's over-hype of having people use them everywhere. The
strongest reason to use EJB entity beans is the deployment configuration
that you can set, and change (in certain cases) with a running ejb cluster.
I can't speak for DAO in this way, but for TopLink and Castor, that is
not really possible. (Currently. I'm working on Castor :-) Not to mention,
container managed persistance takes much away from the developer, and gives
it to the admin; which can be bad, no doubt.
Eh, really it boils down to architecture. Each architecture has a their
limitations. DAO sounds nice, but like EJB, its 'yet-another-layer';
abstraction to provide for flexibility. It may be good (again, I never
used it) but its still a layer. If you don't need that flexibility, then
its a cost/liability.
Virtually,
Ned Wolpert <wo...@codeheadsystems.com> 4e75
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Re: Enterprise Java Beans (EJB)
Posted by "V. Cekvenich" <ba...@newsguy.com>.
Ned Wolpert wrote:
> Correct me if I'm wrong, but its still only the persistance side, right?
> Or would use use it to replace session beans? I can see it replacing
> Entity beans, and the DAO layer uses entity beans; then your session
> beans would talk to the DAO layer which did all (only?) persistance.
>
Any bean that needs persistance should talk trough DAO. (and dao could
be done using Enity beans, or rowset, etc.).
In your case, if you use session beans than right.
> So, it doesn't replace all of EJB, just EJB's entity beans, right?
>
>
However if you find EJB's slow and not scalable, than you would
implement DAO another way. But since you would pull out Enity beans out,
than there is not much reason to keep Session beans. You could just put
regular form bean or java bean in session in some cases and get rid of
EJB server and just use TomCat or Resin. (most app. servers have other
ways to fail over). If you have reson to use session EJBs that use them,
but I can think of no reason anyone would want to uses Enity EJB.
Back to original post.... Implement DAO interface to persisit (even when
using EJB, so you can replace).
v.
>>If you have an interface, such as DAO pattern, you could change the
>>implementation and not affect the rest of your application.
>>So ... make your persistance/CRUD and interface.
>>
>>This lets you change how it does CRUD. You should be able to switch from
>> JDO to EJB or OJB to RowSet/ResulSet.
>>
>>If you have to refactor the whole application to junk EJB or JDO... that
>> would not be great. A simple interface would do ya.
>
>
>
> Virtually,
> Ned Wolpert <wo...@codeheadsystems.com> 4e75
>
>
>
>
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Re: Enterprise Java Beans (EJB)
Posted by Ned Wolpert <wo...@codeheadsystems.com>.
Correct me if I'm wrong, but its still only the persistance side, right?
Or would use use it to replace session beans? I can see it replacing
Entity beans, and the DAO layer uses entity beans; then your session
beans would talk to the DAO layer which did all (only?) persistance.
So, it doesn't replace all of EJB, just EJB's entity beans, right?
> If you have an interface, such as DAO pattern, you could change the
> implementation and not affect the rest of your application.
> So ... make your persistance/CRUD and interface.
>
> This lets you change how it does CRUD. You should be able to switch from
> JDO to EJB or OJB to RowSet/ResulSet.
>
> If you have to refactor the whole application to junk EJB or JDO... that
> would not be great. A simple interface would do ya.
Virtually,
Ned Wolpert <wo...@codeheadsystems.com> 4e75
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Re: Enterprise Java Beans (EJB)
Posted by "V. Cekvenich" <ba...@newsguy.com>.
Very good Jacob!!!!
RowSet is an interface (that extends Resulset).
And suns RowSet implementation does not have source code.
That is why I had Keve and a few other people write an open source
implementation of RowSet. That's right. Open Source RowSet.
It fixes all the bugs and.... did I say you get the source code?
I have 3 clients, one with 40,000 concurrent users using DAO/w RowSet
implementation w/Struts. (EJB can't scale I found beyond very small)
Open Source Row Set implementation:
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/basicportal/src_05d/basicPortal/src/org/sourceforge/jxutil/sql/XDisconnectedRowSet.java?rev=1.1&content-type=text/vnd.viewcvs-markup
DAO implementation:
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/basicportal/src_05d/basicPortal/src/org/apache/commons/DAO/BasicDAOrsImpl.java?rev=1.1.1.1&content-type=text/vnd.viewcvs-markup
hth,
V.
Jacob Hookom wrote:
>
> | -----Original Message-----
> | From: V. Cekvenich [mailto:basebean@newsguy.com]
> | Sent: Thursday, August 15, 2002 10:28 AM
> | To: Tomcat Users List
> | Subject: Re: Enterprise Java Beans (EJB)
> |
> | No....
> | Here is what:
> | Bean (formBean in Struts for example) delegate to DAO for CRUD
> | (Insert,Read, Update,Delete to SQL DB) and persistence, done by DAO.
> | DAO is an interface.
> | The interface could be, inside of the DAO and not known to bean
> | (formBean), implemented inside of the DAO a few different ways.
> | You could have a DAO implementation using EJB or Castor or Jakrta OJB,
> | or RowSet (I use RowSet).
>
> Have you had much luck with RowSet? I check the Sun forums and everyone
> complains. I think it's an awesome framework, but the sun
> implementation is really lacking, features such as createCopy, or
> createShared don't work well if at all in testing what they "say" it
> will do.
>
> RowSet does work with JSTL, so I'm thinking about standardizing RowSet
> with my application as the Model Bean to use with my pages.
>
> -Jacob
>
>
> | If you have an interface, such as DAO pattern, you could change the
> | implementation and not affect the rest of your application.
> | So ... make your persistance/CRUD and interface.
> |
> | This lets you change how it does CRUD. You should be able to switch
> from
> | JDO to EJB or OJB to RowSet/ResulSet.
> |
> | If you have to refactor the whole application to junk EJB or JDO...
> that
> | would not be great. A simple interface would do ya.
> |
> | v.
> |
> |
> | Ned Wolpert wrote:
> | > When you say 'replace EJB with JDO' you mean replacing EJB's entity
> | > beans with DAO, right? (As opposed to session and message beans)
> (I've
> | > never used DAO, just TopLink and CastorJDO instead of Entity beans
> or as
> | > BMP entity beans)
> | >
> | > On Thu, 2002-08-15 at 08:11, V. Cekvenich wrote:
> | >
> | >>Consider draping a DAO around your persistence.
> | >>This way you can replace EJB with JDO or RowSet, should you need to
> | >>Ex DAO interface:
> | >>http://cvs.sourceforge.net/cgi-
> |
> bin/viewcvs.cgi/basicportal/src_05d/basicPortal/src/org/apache/commons/D
> AO
> | /BasicDAO.java?rev=1.1.1.1&content-type=text/vnd.viewcvs-markup
> | >>
> | >>I found a RowSet implementation of DAO works better than EJB.
> | >>
> | >>v.
> | >>
> | >>Ned Wolpert wrote:
> | >>
> | >>>EJB provides a way to easily encapsulate business logic and reduce
> | >>>complexity by moving some difficult functionality/designs into
> | >>>deployment instead of development. Transaction requirements defined
> in
> | >>>the deployment of the EJB beans as opposed to part of the
> development
> | of
> | >>>the EJB beans. (And they are easy to migrate/scale to many
> computers
> | >>>based on deployment configuration, again, making that task easier
> for
> | >>>developers since the programmer does not need to do anything
> special to
> | >>>achieve this.
> | >>>
> | >>>Session beans contain the business logic (Servlets call them)
> | >>>Entity beans persist the info to the database. (Session beans call
> | them)
> | >>>Message beans respond to JMS queues/topics.
> | >>>
> | >>>In reality, EJB is simply another design pattern... one that was
> | >>>over-hyped by the vendors, but can provide flexibility needed in
> some
> | >>>cases.
> | >>>
> | >>>On Wed, 2002-08-14 at 22:34, Josh wrote:
> | >>>
> | >>>
> | >>>>Don't suppose anybody can send me a pointer as to what EJB and
> Jboss
> | >>>>actually achieve? All i managed to glean from their website were
> some
> | pretty
> | >>>>3d variations on the usual "our product in the middle and some
> arrows"
> | >>>>diagrams.
> | >>>>
> | >>>>-Josh
> | >>>>
> | >>>>"Rimmer, real dumplings, proper dumplings when they're properly
> | >>>> cooked to perfection, proper dumplings, should not bounce."
> | >>>>
> | >>>>----- Original Message -----
> | >>>>From: "Nikola Milutinovic" <Ni...@ev.co.yu>
> | >>>>To: "Tomcat Users List" <to...@jakarta.apache.org>
> | >>>>Sent: Thursday, August 15, 2002 3:31 PM
> | >>>>Subject: Re: Enterprise Java Beans (EJB)
> | >>>>
> | >>>>
> | >>>>
> | >>>>
> | >>>>>>Does Tomcat support EJB?.....
> | >>>>>
> | >>>>>No, it is not the task of Tomcat.
> | >>>>>
> | >>>>>
> | >>>>>
> | >>>>>>if not, is there a project to migrate tomcat to support EJB?...
> it
> | will
> | >>>>>
> | >>>>be
> | >>>>
> | >>>>
> | >>>>>>a very nice feature...
> | >>>>>
> | >>>>>Other servers, like JBoss, are EJB containers, Tomcat can
> | >>>>
> | >>>>connect/integrate with them. There is a version of JBoss that
> comes
> | bundled
> | >>>>with Tomcat. Take a look at http://www.jboss.org/
> | >>>>
> | >>>>
> | >>>>>Nix.
> | >>>>>
> | >>>>
> | >>>>
> | >>>>--
> | >>>>To unsubscribe, e-mail: <mailto:tomcat-user-
> | unsubscribe@jakarta.apache.org>
> | >>>>For additional commands, e-mail: <mailto:tomcat-user-
> | help@jakarta.apache.org>
> | >>>>
> | >>>>
> | >>
> | >>
> | >>--
> | >>To unsubscribe, e-mail: <mailto:tomcat-user-
> | unsubscribe@jakarta.apache.org>
> | >>For additional commands, e-mail: <mailto:tomcat-user-
> | help@jakarta.apache.org>
> | >>
> | >>
> |
> |
> |
> | --
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RE: Enterprise Java Beans (EJB)
Posted by Jacob Hookom <ho...@uwec.edu>.
| -----Original Message-----
| From: V. Cekvenich [mailto:basebean@newsguy.com]
| Sent: Thursday, August 15, 2002 10:28 AM
| To: Tomcat Users List
| Subject: Re: Enterprise Java Beans (EJB)
|
| No....
| Here is what:
| Bean (formBean in Struts for example) delegate to DAO for CRUD
| (Insert,Read, Update,Delete to SQL DB) and persistence, done by DAO.
| DAO is an interface.
| The interface could be, inside of the DAO and not known to bean
| (formBean), implemented inside of the DAO a few different ways.
| You could have a DAO implementation using EJB or Castor or Jakrta OJB,
| or RowSet (I use RowSet).
Have you had much luck with RowSet? I check the Sun forums and everyone
complains. I think it's an awesome framework, but the sun
implementation is really lacking, features such as createCopy, or
createShared don't work well if at all in testing what they "say" it
will do.
RowSet does work with JSTL, so I'm thinking about standardizing RowSet
with my application as the Model Bean to use with my pages.
-Jacob
| If you have an interface, such as DAO pattern, you could change the
| implementation and not affect the rest of your application.
| So ... make your persistance/CRUD and interface.
|
| This lets you change how it does CRUD. You should be able to switch
from
| JDO to EJB or OJB to RowSet/ResulSet.
|
| If you have to refactor the whole application to junk EJB or JDO...
that
| would not be great. A simple interface would do ya.
|
| v.
|
|
| Ned Wolpert wrote:
| > When you say 'replace EJB with JDO' you mean replacing EJB's entity
| > beans with DAO, right? (As opposed to session and message beans)
(I've
| > never used DAO, just TopLink and CastorJDO instead of Entity beans
or as
| > BMP entity beans)
| >
| > On Thu, 2002-08-15 at 08:11, V. Cekvenich wrote:
| >
| >>Consider draping a DAO around your persistence.
| >>This way you can replace EJB with JDO or RowSet, should you need to
| >>Ex DAO interface:
| >>http://cvs.sourceforge.net/cgi-
|
bin/viewcvs.cgi/basicportal/src_05d/basicPortal/src/org/apache/commons/D
AO
| /BasicDAO.java?rev=1.1.1.1&content-type=text/vnd.viewcvs-markup
| >>
| >>I found a RowSet implementation of DAO works better than EJB.
| >>
| >>v.
| >>
| >>Ned Wolpert wrote:
| >>
| >>>EJB provides a way to easily encapsulate business logic and reduce
| >>>complexity by moving some difficult functionality/designs into
| >>>deployment instead of development. Transaction requirements defined
in
| >>>the deployment of the EJB beans as opposed to part of the
development
| of
| >>>the EJB beans. (And they are easy to migrate/scale to many
computers
| >>>based on deployment configuration, again, making that task easier
for
| >>>developers since the programmer does not need to do anything
special to
| >>>achieve this.
| >>>
| >>>Session beans contain the business logic (Servlets call them)
| >>>Entity beans persist the info to the database. (Session beans call
| them)
| >>>Message beans respond to JMS queues/topics.
| >>>
| >>>In reality, EJB is simply another design pattern... one that was
| >>>over-hyped by the vendors, but can provide flexibility needed in
some
| >>>cases.
| >>>
| >>>On Wed, 2002-08-14 at 22:34, Josh wrote:
| >>>
| >>>
| >>>>Don't suppose anybody can send me a pointer as to what EJB and
Jboss
| >>>>actually achieve? All i managed to glean from their website were
some
| pretty
| >>>>3d variations on the usual "our product in the middle and some
arrows"
| >>>>diagrams.
| >>>>
| >>>>-Josh
| >>>>
| >>>>"Rimmer, real dumplings, proper dumplings when they're properly
| >>>> cooked to perfection, proper dumplings, should not bounce."
| >>>>
| >>>>----- Original Message -----
| >>>>From: "Nikola Milutinovic" <Ni...@ev.co.yu>
| >>>>To: "Tomcat Users List" <to...@jakarta.apache.org>
| >>>>Sent: Thursday, August 15, 2002 3:31 PM
| >>>>Subject: Re: Enterprise Java Beans (EJB)
| >>>>
| >>>>
| >>>>
| >>>>
| >>>>>>Does Tomcat support EJB?.....
| >>>>>
| >>>>>No, it is not the task of Tomcat.
| >>>>>
| >>>>>
| >>>>>
| >>>>>>if not, is there a project to migrate tomcat to support EJB?...
it
| will
| >>>>>
| >>>>be
| >>>>
| >>>>
| >>>>>>a very nice feature...
| >>>>>
| >>>>>Other servers, like JBoss, are EJB containers, Tomcat can
| >>>>
| >>>>connect/integrate with them. There is a version of JBoss that
comes
| bundled
| >>>>with Tomcat. Take a look at http://www.jboss.org/
| >>>>
| >>>>
| >>>>>Nix.
| >>>>>
| >>>>
| >>>>
| >>>>--
| >>>>To unsubscribe, e-mail: <mailto:tomcat-user-
| unsubscribe@jakarta.apache.org>
| >>>>For additional commands, e-mail: <mailto:tomcat-user-
| help@jakarta.apache.org>
| >>>>
| >>>>
| >>
| >>
| >>--
| >>To unsubscribe, e-mail: <mailto:tomcat-user-
| unsubscribe@jakarta.apache.org>
| >>For additional commands, e-mail: <mailto:tomcat-user-
| help@jakarta.apache.org>
| >>
| >>
|
|
|
| --
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Re: Enterprise Java Beans (EJB)
Posted by "V. Cekvenich" <ba...@newsguy.com>.
No....
Here is what:
Bean (formBean in Struts for example) delegate to DAO for CRUD
(Insert,Read, Update,Delete to SQL DB) and persistence, done by DAO.
DAO is an interface.
The interface could be, inside of the DAO and not known to bean
(formBean), implemented inside of the DAO a few different ways.
You could have a DAO implementation using EJB or Castor or Jakrta OJB,
or RowSet (I use RowSet).
If you have an interface, such as DAO pattern, you could change the
implementation and not affect the rest of your application.
So ... make your persistance/CRUD and interface.
This lets you change how it does CRUD. You should be able to switch from
JDO to EJB or OJB to RowSet/ResulSet.
If you have to refactor the whole application to junk EJB or JDO... that
would not be great. A simple interface would do ya.
v.
Ned Wolpert wrote:
> When you say 'replace EJB with JDO' you mean replacing EJB's entity
> beans with DAO, right? (As opposed to session and message beans) (I've
> never used DAO, just TopLink and CastorJDO instead of Entity beans or as
> BMP entity beans)
>
> On Thu, 2002-08-15 at 08:11, V. Cekvenich wrote:
>
>>Consider draping a DAO around your persistence.
>>This way you can replace EJB with JDO or RowSet, should you need to
>>Ex DAO interface:
>>http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/basicportal/src_05d/basicPortal/src/org/apache/commons/DAO/BasicDAO.java?rev=1.1.1.1&content-type=text/vnd.viewcvs-markup
>>
>>I found a RowSet implementation of DAO works better than EJB.
>>
>>v.
>>
>>Ned Wolpert wrote:
>>
>>>EJB provides a way to easily encapsulate business logic and reduce
>>>complexity by moving some difficult functionality/designs into
>>>deployment instead of development. Transaction requirements defined in
>>>the deployment of the EJB beans as opposed to part of the development of
>>>the EJB beans. (And they are easy to migrate/scale to many computers
>>>based on deployment configuration, again, making that task easier for
>>>developers since the programmer does not need to do anything special to
>>>achieve this.
>>>
>>>Session beans contain the business logic (Servlets call them)
>>>Entity beans persist the info to the database. (Session beans call them)
>>>Message beans respond to JMS queues/topics.
>>>
>>>In reality, EJB is simply another design pattern... one that was
>>>over-hyped by the vendors, but can provide flexibility needed in some
>>>cases.
>>>
>>>On Wed, 2002-08-14 at 22:34, Josh wrote:
>>>
>>>
>>>>Don't suppose anybody can send me a pointer as to what EJB and Jboss
>>>>actually achieve? All i managed to glean from their website were some pretty
>>>>3d variations on the usual "our product in the middle and some arrows"
>>>>diagrams.
>>>>
>>>>-Josh
>>>>
>>>>"Rimmer, real dumplings, proper dumplings when they're properly
>>>> cooked to perfection, proper dumplings, should not bounce."
>>>>
>>>>----- Original Message -----
>>>>From: "Nikola Milutinovic" <Ni...@ev.co.yu>
>>>>To: "Tomcat Users List" <to...@jakarta.apache.org>
>>>>Sent: Thursday, August 15, 2002 3:31 PM
>>>>Subject: Re: Enterprise Java Beans (EJB)
>>>>
>>>>
>>>>
>>>>
>>>>>>Does Tomcat support EJB?.....
>>>>>
>>>>>No, it is not the task of Tomcat.
>>>>>
>>>>>
>>>>>
>>>>>>if not, is there a project to migrate tomcat to support EJB?... it will
>>>>>
>>>>be
>>>>
>>>>
>>>>>>a very nice feature...
>>>>>
>>>>>Other servers, like JBoss, are EJB containers, Tomcat can
>>>>
>>>>connect/integrate with them. There is a version of JBoss that comes bundled
>>>>with Tomcat. Take a look at http://www.jboss.org/
>>>>
>>>>
>>>>>Nix.
>>>>>
>>>>
>>>>
>>>>--
>>>>To unsubscribe, e-mail: <ma...@jakarta.apache.org>
>>>>For additional commands, e-mail: <ma...@jakarta.apache.org>
>>>>
>>>>
>>
>>
>>--
>>To unsubscribe, e-mail: <ma...@jakarta.apache.org>
>>For additional commands, e-mail: <ma...@jakarta.apache.org>
>>
>>
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Re: Enterprise Java Beans (EJB)
Posted by Ned Wolpert <wo...@codeheadsystems.com>.
When you say 'replace EJB with JDO' you mean replacing EJB's entity
beans with DAO, right? (As opposed to session and message beans) (I've
never used DAO, just TopLink and CastorJDO instead of Entity beans or as
BMP entity beans)
On Thu, 2002-08-15 at 08:11, V. Cekvenich wrote:
> Consider draping a DAO around your persistence.
> This way you can replace EJB with JDO or RowSet, should you need to
> Ex DAO interface:
> http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/basicportal/src_05d/basicPortal/src/org/apache/commons/DAO/BasicDAO.java?rev=1.1.1.1&content-type=text/vnd.viewcvs-markup
>
> I found a RowSet implementation of DAO works better than EJB.
>
> v.
>
> Ned Wolpert wrote:
> > EJB provides a way to easily encapsulate business logic and reduce
> > complexity by moving some difficult functionality/designs into
> > deployment instead of development. Transaction requirements defined in
> > the deployment of the EJB beans as opposed to part of the development of
> > the EJB beans. (And they are easy to migrate/scale to many computers
> > based on deployment configuration, again, making that task easier for
> > developers since the programmer does not need to do anything special to
> > achieve this.
> >
> > Session beans contain the business logic (Servlets call them)
> > Entity beans persist the info to the database. (Session beans call them)
> > Message beans respond to JMS queues/topics.
> >
> > In reality, EJB is simply another design pattern... one that was
> > over-hyped by the vendors, but can provide flexibility needed in some
> > cases.
> >
> > On Wed, 2002-08-14 at 22:34, Josh wrote:
> >
> >>Don't suppose anybody can send me a pointer as to what EJB and Jboss
> >>actually achieve? All i managed to glean from their website were some pretty
> >>3d variations on the usual "our product in the middle and some arrows"
> >>diagrams.
> >>
> >>-Josh
> >>
> >>"Rimmer, real dumplings, proper dumplings when they're properly
> >> cooked to perfection, proper dumplings, should not bounce."
> >>
> >>----- Original Message -----
> >>From: "Nikola Milutinovic" <Ni...@ev.co.yu>
> >>To: "Tomcat Users List" <to...@jakarta.apache.org>
> >>Sent: Thursday, August 15, 2002 3:31 PM
> >>Subject: Re: Enterprise Java Beans (EJB)
> >>
> >>
> >>
> >>>>Does Tomcat support EJB?.....
> >>>
> >>>No, it is not the task of Tomcat.
> >>>
> >>>
> >>>>if not, is there a project to migrate tomcat to support EJB?... it will
> >>>
> >>be
> >>
> >>>>a very nice feature...
> >>>
> >>>Other servers, like JBoss, are EJB containers, Tomcat can
> >>
> >>connect/integrate with them. There is a version of JBoss that comes bundled
> >>with Tomcat. Take a look at http://www.jboss.org/
> >>
> >>>Nix.
> >>>
> >>
> >>
> >>--
> >>To unsubscribe, e-mail: <ma...@jakarta.apache.org>
> >>For additional commands, e-mail: <ma...@jakarta.apache.org>
> >>
> >>
>
>
>
> --
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>
>
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Virtually,
Ned Wolpert <wo...@codeheadsystems.com> 4e75
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Re: Enterprise Java Beans (EJB)
Posted by "V. Cekvenich" <ba...@newsguy.com>.
Consider draping a DAO around your persistence.
This way you can replace EJB with JDO or RowSet, should you need to
Ex DAO interface:
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/basicportal/src_05d/basicPortal/src/org/apache/commons/DAO/BasicDAO.java?rev=1.1.1.1&content-type=text/vnd.viewcvs-markup
I found a RowSet implementation of DAO works better than EJB.
v.
Ned Wolpert wrote:
> EJB provides a way to easily encapsulate business logic and reduce
> complexity by moving some difficult functionality/designs into
> deployment instead of development. Transaction requirements defined in
> the deployment of the EJB beans as opposed to part of the development of
> the EJB beans. (And they are easy to migrate/scale to many computers
> based on deployment configuration, again, making that task easier for
> developers since the programmer does not need to do anything special to
> achieve this.
>
> Session beans contain the business logic (Servlets call them)
> Entity beans persist the info to the database. (Session beans call them)
> Message beans respond to JMS queues/topics.
>
> In reality, EJB is simply another design pattern... one that was
> over-hyped by the vendors, but can provide flexibility needed in some
> cases.
>
> On Wed, 2002-08-14 at 22:34, Josh wrote:
>
>>Don't suppose anybody can send me a pointer as to what EJB and Jboss
>>actually achieve? All i managed to glean from their website were some pretty
>>3d variations on the usual "our product in the middle and some arrows"
>>diagrams.
>>
>>-Josh
>>
>>"Rimmer, real dumplings, proper dumplings when they're properly
>> cooked to perfection, proper dumplings, should not bounce."
>>
>>----- Original Message -----
>>From: "Nikola Milutinovic" <Ni...@ev.co.yu>
>>To: "Tomcat Users List" <to...@jakarta.apache.org>
>>Sent: Thursday, August 15, 2002 3:31 PM
>>Subject: Re: Enterprise Java Beans (EJB)
>>
>>
>>
>>>>Does Tomcat support EJB?.....
>>>
>>>No, it is not the task of Tomcat.
>>>
>>>
>>>>if not, is there a project to migrate tomcat to support EJB?... it will
>>>
>>be
>>
>>>>a very nice feature...
>>>
>>>Other servers, like JBoss, are EJB containers, Tomcat can
>>
>>connect/integrate with them. There is a version of JBoss that comes bundled
>>with Tomcat. Take a look at http://www.jboss.org/
>>
>>>Nix.
>>>
>>
>>
>>--
>>To unsubscribe, e-mail: <ma...@jakarta.apache.org>
>>For additional commands, e-mail: <ma...@jakarta.apache.org>
>>
>>
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Re: Enterprise Java Beans (EJB)
Posted by Ned Wolpert <wo...@codeheadsystems.com>.
EJB provides a way to easily encapsulate business logic and reduce
complexity by moving some difficult functionality/designs into
deployment instead of development. Transaction requirements defined in
the deployment of the EJB beans as opposed to part of the development of
the EJB beans. (And they are easy to migrate/scale to many computers
based on deployment configuration, again, making that task easier for
developers since the programmer does not need to do anything special to
achieve this.
Session beans contain the business logic (Servlets call them)
Entity beans persist the info to the database. (Session beans call them)
Message beans respond to JMS queues/topics.
In reality, EJB is simply another design pattern... one that was
over-hyped by the vendors, but can provide flexibility needed in some
cases.
On Wed, 2002-08-14 at 22:34, Josh wrote:
> Don't suppose anybody can send me a pointer as to what EJB and Jboss
> actually achieve? All i managed to glean from their website were some pretty
> 3d variations on the usual "our product in the middle and some arrows"
> diagrams.
>
> -Josh
>
> "Rimmer, real dumplings, proper dumplings when they're properly
> cooked to perfection, proper dumplings, should not bounce."
>
> ----- Original Message -----
> From: "Nikola Milutinovic" <Ni...@ev.co.yu>
> To: "Tomcat Users List" <to...@jakarta.apache.org>
> Sent: Thursday, August 15, 2002 3:31 PM
> Subject: Re: Enterprise Java Beans (EJB)
>
>
> > > Does Tomcat support EJB?.....
> >
> > No, it is not the task of Tomcat.
> >
> > > if not, is there a project to migrate tomcat to support EJB?... it will
> be
> > > a very nice feature...
> >
> > Other servers, like JBoss, are EJB containers, Tomcat can
> connect/integrate with them. There is a version of JBoss that comes bundled
> with Tomcat. Take a look at http://www.jboss.org/
> >
> > Nix.
> >
>
>
> --
> To unsubscribe, e-mail: <ma...@jakarta.apache.org>
> For additional commands, e-mail: <ma...@jakarta.apache.org>
>
>
--
Virtually,
Ned Wolpert <wo...@codeheadsystems.com> 4e75
--
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Re: Enterprise Java Beans (EJB)
Posted by Nikola Milutinovic <Ni...@ev.co.yu>.
> Don't suppose anybody can send me a pointer as to what EJB and Jboss
> actually achieve? All i managed to glean from their website were some pretty
> 3d variations on the usual "our product in the middle and some arrows"
> diagrams.
My knowledge of EJB is informational. EJB as are JEE components, managed by EJB Servers, like JBoss. EJB main function is to introduce persistance and business logic, in general, (can we say that persistance IS a part of business logic? :-)) into the world of JEE applications.
Tomcat, from that view, is just one of the portals of a JEE application. So, the chain of modules would be:
Web Server (Apache)
+
Servlet/JSP container (Tomcat)
+
EJB container (JBoss - EJBs, transactions, messages)
+
Persistant storage + other data portals (DBs, legacy APIs and other means information exchange)
Nix.
Re: Enterprise Java Beans (EJB)
Posted by Josh <jo...@isa.net.au>.
Don't suppose anybody can send me a pointer as to what EJB and Jboss
actually achieve? All i managed to glean from their website were some pretty
3d variations on the usual "our product in the middle and some arrows"
diagrams.
-Josh
"Rimmer, real dumplings, proper dumplings when they're properly
cooked to perfection, proper dumplings, should not bounce."
----- Original Message -----
From: "Nikola Milutinovic" <Ni...@ev.co.yu>
To: "Tomcat Users List" <to...@jakarta.apache.org>
Sent: Thursday, August 15, 2002 3:31 PM
Subject: Re: Enterprise Java Beans (EJB)
> > Does Tomcat support EJB?.....
>
> No, it is not the task of Tomcat.
>
> > if not, is there a project to migrate tomcat to support EJB?... it will
be
> > a very nice feature...
>
> Other servers, like JBoss, are EJB containers, Tomcat can
connect/integrate with them. There is a version of JBoss that comes bundled
with Tomcat. Take a look at http://www.jboss.org/
>
> Nix.
>
--
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Re: Enterprise Java Beans (EJB)
Posted by Nikola Milutinovic <Ni...@ev.co.yu>.
> Does Tomcat support EJB?.....
No, it is not the task of Tomcat.
> if not, is there a project to migrate tomcat to support EJB?... it will be
> a very nice feature...
Other servers, like JBoss, are EJB containers, Tomcat can connect/integrate with them. There is a version of JBoss that comes bundled with Tomcat. Take a look at http://www.jboss.org/
Nix.