Ali Aman

Greenhorn
+ Follow
since Jun 05, 2006
Cows and Likes
Cows
Total received
0
In last 30 days
0
Total given
0
Likes
Total received
0
Received in last 30 days
0
Total given
0
Given in last 30 days
0
Forums and Threads
Scavenger Hunt
expand Ranch Hand Scavenger Hunt
expand Greenhorn Scavenger Hunt

Recent posts by Ali Aman

the Entity bean has some abstract functions in the EJBObject interface...

Example create, remove etc...

By simply providing the primary key as an argument i.e.
create(primary_key) the container automaticaly inserts a record in a table.. similarly there is another function remove thru which one can simply call the function like this... remove(primary_key) and the container would remove the record in the table...

However if the developer wishes to perfrom these transactions by running sql scripts he uses bean managed transactions and codes it thus called Bean Managed Trasactions.
Basically Entity Beans are used to connect to the Database (it is not a good practice to connect to a database thru a Statless or Stateful Session bean) thru a JNDI Name.... JNDI Naming makes it easier to connect in an enterprise becuase it abstracts the datasource classname etc from the developer,

The main advantage of using EJBs over Simple beans is that J2EE has a moto of develop once deploy many, if there is a slight change in business logic etc, the developer can change the business requirements and redeploy the bean and the client wouldnt have a whiff about it.

Other than that there are many features in EJBs, for example the Container Managed Persistance in Entity Beans enable you to find, create, delete, update records in your database without going thru the hinderance of writing SQL Scripts which increases database integrity, another feature of Entity Beans is Container Managed Relationships which maintains schema integrity....

These are just some benefits that I guess are benefitial in a large environment over legacy systems when we compare EJBs and normal Java classes.
when deploying.. it gives me a message... progress object not running...???

I have initiated server instance (installed re-installed) several times...
it doesnt seem to work!!!
I have an error in deployment...

----------------------------------------------------------------------
distribute: D:\StockListApp.ear
Cannot deploy. Module already exists. Set force=true for redeployment.; requested operation cannot be completed

!!! Operation Failed !!!
!!! With The Following Failure Messages !!!
Cannot deploy. Module already exists. Set force=true for redeployment.; requested operation cannot be completed


**********************************************************************
[Completed (time=1.7sec, status=13)]
**********************************************************************



what shud I do..........................................


Other than that when I try to undeploy the application etc form the GUI admin console and when I click Enterprise Applications it gives the following exception? Please help

A "com.sun.enterprise.tools.guiframework.exception.FrameworkError" was caught. The message from the exception: "Unable to get View for ViewDescriptor 'enterpriseApplications'"

The root cause is "com.sun.enterprise.admin.common.exception.MBeanConfigException: Component not registered"

See the HTML source for more detailed (stack trace) information.
ali.amaan@gmail.com


Hi All!!
I am using the Sun Java Systems Application Server, I am learning to build EJBs; I have problems connection to the database when I am using the Entity Bean, when I log in to the Admin console an I try to ping to the database "DERBY" through the DerbyPool (in the connections Pool) I get the following error:

Operation 'pingConnectionPool' failed in 'resources' Config Mbean. Target exception message: Connection could not be allocated because: java.security.PrivilegedActionException : Error opening socket to server localhost on port 1527 with message : null

Can anyone help? :roll:
contact is below

ali.amaan@gmail.com