Ali Reza Hosseini

Ranch Hand
+ Follow
since Apr 28, 2005
Merit badge: grant badges
For More
Cows and Likes
Total received
In last 30 days
Total given
Total received
Received in last 30 days
Total given
Given in last 30 days
Forums and Threads
Scavenger Hunt
expand Ranch Hand Scavenger Hunt
expand Greenhorn Scavenger Hunt

Recent posts by Ali Reza Hosseini


I am having a method which has two parameters in its signature like this:

What I want to do is to make this method available via REST like this:

Is it possible to expose this method as a RESTFul service method although it has more than one entity in its signature?

I ask this because in jersey's api I do not see any way to pass more than one entity to the webResource when calling post()-method.
12 years ago

is there a way to remove an ejb mdb (message driven bean) instance running on a WAS without stopping and restarting it?
18 years ago
Is there a way to connect a jee 1.5 swing client to a j2ee 1.4 ejb server
an let the client use the ejbs there?

When I try to do this I get the following exception

Cannot use a 1.3.x ORB with a 1.4.x JDK
Exception in thread "P=469187 =0:CT" javax.naming.NamingException: Failed to initialize the ORB [Root exception is org.omg.CORBA.INITIALIZE: java.lang.Exception: Cannot use a 1.3.x ORB with a 1.4.x JDK vmcid: 0x4942f000 minor code: 1285 completed: No]
at javax.naming.InitialContext.addToEnvironment(Unknown Source)
at test.main(
Caused by: org.omg.CORBA.INITIALIZE: java.lang.Exception: Cannot use a 1.3.x ORB with a 1.4.x JDK vmcid: 0x4942f000 minor code: 1285 completed: No
at org.omg.CORBA.ORB.init(Unknown Source)
... 6 more
18 years ago

I'm writing a client to access ejbs on a websphere 5.1.2

I can put the user and its password in
the sas.client.prop file, so the login prompt doesn't need to apear.

But how can I pass user/password programatically to connect to server?

I search many topics in infocenter but i didn'd find any hint.

does any body have an idea?

18 years ago
ok, this was my first consideration, but somewhere i read that a client can only get those messages which arrived in the topic after it has subscribed
the topic. The client has no access to those messages which
was published before it has subscribed the topic.

imagine the following situation:
A client starts and want to get the current state of the system.
The topic will propagate a new state only if there is a change on
system's state. How will the client get the information about the
current state, if there is no message published after it has subscribed
the topic?
How can I implement an Observer/Observable Pattern with EJB technology.

I intend to have a server component
which holds the system's state for alle the clients who subscribe
for this state (One state for all client). The server component has to notify all clients if the system state changes.

Which technology is prefered to do this?

A SFSB does not seem to be the right one because it can
only hold one client's state.

A SLSB is not the right choise because it does not provide any state at all ..

The only one remaining is an entity bean but that means having the state
saved in a RDBMS ..

What if I don't want to save the system's state in a RDBMS?

Is there any other way for implementing a server component
which can be refered by many clients and provide them the same state?

thanks for your advise ..


about three months after passing part one, yesterday I uploaded
my part two solution and I am going to take part three.

is there anything I can do to prepare myself for part three
beyond reviewing my part two solution? should I take a look
at all that stuff I had to know for part one?

many thanks for you hints!


generally spoken you are right ..

but in this particular case where it is intended to save a client's conversational state in a stateful session bean, would you let a client
access its state over a session facade?

i think this is a little bit over engineered ..

some of my colleagues are designing
a sfsb with local interfaces!!! for clients
conversational state ...

I am wondering if it actually does make sense to have
an SFSB with only local interfaces and allow a client
to access this sfsb over a session facade which is
stateless itself ..

what do you mean? are my colleagues right to do it that way?

thanks ...
You can use IDL to generate java stubs to access a corba-based service.
RMI IIOP is often used if you have to access an ejb-based service.
from my point of view a system architect mainly has to care about
infrastructure and server components and their relationships
and connections ( Machines + Network + OS + Serversystems ).

an application architect has to care about the application
components and their relationships and their distribution
(right decomposition of an application into components + using patterns +
building prototypes + place components along the existing infrastructure)

actually, these both skills overlap in some areas and a
cooperation between them is essentail (e.g. for sizing issues).

Originally posted by jason white:
I started with sequence diagrams and everything evolved nicely from there.

I did spend a minimum of time at the beginning extending some classes in the class diagram but changed those as the sequence diagrams came along.



the question is: does a sequence diagram have to deal with all those objects derived by pattern usage or specific technology e.g. EJB.

you can make a sequence diagram with boundaries, controls and entities,
whitout taking care about business delegates, service locators or home interfaces of some ejbs. is this way advisable?

i think it is, because if you had to take all those technical objects into
play, the sequence diagrams would get humongous and a little bit unreadable.

what do you mean?

Is it recommended to do part II the way sun teaches in course SL425?

This means to do..

1. A robustness analysis by creating high level collaboration diagrams for each use case with technology independent Jacobsen components (boundaries, controls and entities).

2. And then create an architectural model by creating component & deployment diagrams.

This implies than the collaboration/sequence diagrams do not necessarily need to deal with pattern or j2ee specific components. Do these components only appear in the architectural model by reification?

Originally posted by Koen Serneels:
A credit card authorization system is per default synchronous.

So, before sending the CC information to the CC company, you need to obatin a database lock on the table responsible for holding the reserved seats for a flight.


i have a question about that "lock" you mentioned:
as i learned, it is possible to specify an isolation level for a database connection which is provided by the conection pool.
to have a lock on a table you have to set the connection's isolation level on "Serializable" or how do you assure that the table is locked?

OK, but I think that the uml specs are wrong at this position ...

.. because ..

as there stays about the definition of dynamic view: " .. That aspect of a model dealing with the specification and implementation over time .."

but usecase diagrams do not include any information about
specification and implementation OVER TIME ...

from a scientific point of view, I vehemently disagree with that !!!