Joins in Entity Bean

Hello everyone,
How to achieve joins in EJB?
Thanks in advance

BMPs are the best ones to use when u have joins(esply complicated).
Most of the EJB containers don't support CMPs with more than 1 or 2 tables.
Thanks,

Similar Messages

Problem with ejb 3.0 entity beans with manyToMany relationship

Hello everyone!
I am using struts 1.2.9 and java ee 5 sdk update 2 for my enterprise application. Besides others i have these entity beans Targetgroup.java and City.java, (i would upload file but i do not know how:)
with manytomany relationship with join table.
when user updates Targetgroup, by clicking on web page with checkboxes and textfields, struts dispatch action calls following method stateless bean:
public void update(String firmId, String targetgroupId, String newGender, String newMinYearsOld, String newMaxYearsOld, String[] newCities) {
TargetgroupPK pkForUpdate = new TargetgroupPK(targetgroupId, firmId);
Targetgroup targetgroupForUpdate = find(pkForUpdate);
targetgroupForUpdate.setGender(newGender);
targetgroupForUpdate.setMinyearold(Integer.parseIn t(newMinYearsOld));
targetgroupForUpdate.setMaxyearold(Integer.parseIn t(newMaxYearsOld));
//pronalazenje gradva za koje je vezana ciljna grupa
Collection<City> newCitiesCollection = new ArrayList<City>();
for(int i = 0; i < newCities.length; i++){
String tmp_city_name = newCities;
City city_obj = cityFacade.find(tmp_city_name);
newCitiesCollection.add(city_obj);
targetgroupForUpdate.setCityidCollection(newCities Collection);
parameter newCities represents names of cities which user checked on his update page. When the page is showen to him some cities are allready check because they were connected with Targetgruoup when it was created (targetgroup).
this code throws following exception:
[#|2007-07-26T12:13:36.993+0200|SEVERE|sun-appserver-pe9.0|javax.enterprise.system.container.web|_Threa dID=16;_ThreadName=httpWorkerThread-8080-0;_RequestID=f79d9c50-86b0-4b6c-96ab-97956dfb39c1;|StandardWrapperValve[action]: Servlet.service() for servlet action threw exception
javax.ejb.EJBException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaction marked for rollback.
javax.transaction.RollbackException: Transaction marked for rollback.
at
.com.sun.enterprise.web.connector.grizzly.WorkerTh read.run(WorkerThread.java:75)
javax.ejb.EJBException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaction marked for rollback.
at com.sun.ejb.containers.BaseContainer.completeNewTx (BaseContainer.java:3659)
at com.sun.ejb.containers.BaseContainer.postInvokeTx( BaseContainer.java:3431)
at com.sun.ejb.containers.BaseContainer.postInvoke(Ba seContainer.java:1247)
at com.sun.ejb.containers.EJBLocalObjectInvocationHan dler.invoke(EJBLocalObjectInvocationHandler.java:1 92)
at com.sun.ejb.containers.EJBLocalObjectInvocationHan dlerDelegate.invoke(EJBLocalObjectInvocationHandle rDelegate.java:71)
at $Proxy149.update(Unknown Source)
at audiotel.sms.actions.backoffice.TargetgroupDispatc hAction.updateOrDelete(TargetgroupDispatchAction.j ava:132)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Nativ e Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Native MethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(De legatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.struts.actions.DispatchAction.dispatchM ethod(DispatchAction.java:270)
at org.apache.struts.actions.DispatchAction.execute(D ispatchAction.java:187)
at org.apache.struts.action.RequestProcessor.processA ctionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process( RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(Act ionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(Acti onServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:727)
com.sun.enterprise.web.connector.grizzly.WorkerThr ead.run(WorkerThread.java:75)
|#]
exceprion is throwen ONLY when in parameter newCities are city names allready connected to Targetgroup. when NewCities contains names of
City objects which are not connected to Targetgroup it works fine, but it's of no use for me, because user must be able to add or remove certian cities from relaionship with Targetgroup. I think it's because there are rows in join table that contain primary keys of city and targetgroup which are connected so perisistence manager cann't write them again.
i thought it was going to figure it out by itself, and only update those rows.
Does anyone know what is the problem and solution?
Thanks! (forgive my spelling errors :)

solved the problem!
I moved code from sesion bean to struts action as follows:
CityFacadeLocal cityFacade = lookupCityFacade();
//prikupljanje novih podataka o ciljnoj grupi
String newGender = ctf.getGender();
String newMaxYears = ctf.getMaxyears();
String newMinYears = ctf.getMinyears();
String[] newSelectedCities = ctf.getSelectedCities();
//niz imena gradova se prevodi u kolekcju objekata City
Collection<City> newCitiesObjCollection = new Vector<City>();
for(int i = 0; i < newSelectedCities.length; i++){
String tmpCityName = newSelectedCities;
City tmpCityObj = cityFacade.find(tmpCityName);
newCitiesObjCollection.add(tmpCityObj);
//setovanje novih podataka
targetgroupForUD.setGender(newGender);
targetgroupForUD.setMinyearold(Integer.parseInt(newMinYears));
targetgroupForUD.setMaxyearold(Integer.parseInt(newMaxYears));
targetgroupForUD.setCityidCollection(newCitiesObjCollection);
//pozivanje update metdoe u session beany
targetgroupFacade.edit(targetgroupForUD);
//korisnik se vraca na stranu sa svim postojecim ciljnim grupama
forward = mapping.findForward("backend.targetgroups");
and now it works fine. I guess probelm was same transaction scope for Targetgroup and City entities. Now when they are separated it works.
Thanks!

Data Warehouse report query using Entity Beans

I have used the EJB technology on one project, so I am not all that familiar with
best practices.
In my new project, I have to produce reports using a query that goes against a
dimensional database. I am wondering what options I have to run the query and
extract the results given that the application will run on WebLogic.
1) Straight JDBC
2) BMP
3) CMP (could be a problem because the quety is a join query, but I am not sure
if WebLogic requires that the query is against a table rather than a view)
The query is read-only. I am more interested in ease of coding and code management
rather than application performance at this point because I think the query will
spend a relatively large time executing on the Oracle database.
I would like to hear the best practices to be employed in this case. Thanks very
much!
Ravi.

Don't use entity beans for this. Straight JDBC is not perfect either, but it
is preferable to entity beans for this type of work.
Peace,
Cameron Purdy
Tangosol, Inc.
Clustering Weblogic? You're either using Coherence, or you should be!
Download a Tangosol Coherence eval today at http://www.tangosol.com/
"Ravi Navanee" <[email protected]> wrote in message
news:3c92693d$[email protected]..
>
I have used the EJB technology on one project, so I am not all thatfamiliar with
best practices.
In my new project, I have to produce reports using a query that goesagainst a
dimensional database. I am wondering what options I have to run the queryand
extract the results given that the application will run on WebLogic.
1) Straight JDBC
2) BMP
3) CMP (could be a problem because the quety is a join query, but I am notsure
if WebLogic requires that the query is against a table rather than a view)
The query is read-only. I am more interested in ease of coding and codemanagement
rather than application performance at this point because I think thequery will
spend a relatively large time executing on the Oracle database.
I would like to hear the best practices to be employed in this case.Thanks very
much!
Ravi.

Problem in deploying CMP entity bean 2.0 in J2EE 1.4

i am trying to deploy a cmp entity bean 2.0 using j2ee1.4 deployment tool. the bean uses sql server as the database. i have successfully created a coonection pool for sql server using j2ee admin console. the entity bean class files are successfully compiled. but while deploying the entity bean i am not able to set the database settings and jndi name for the bean. can one please guide me in the deployment steps in j2ee1.4.
mohit

Mohit,
We are discussing this topic in the fourm below. I'm having the same problem so feel free to join our conversation.
~Howard
http://forum.java.sun.com/thread.jsp?forum=13&thread=478054

Using a CMP Entity Bean local stub as a field of another CMP Entity Bean

Hello,
Is it possible to implement a field of a CMP Entity bean as another CMP Entity bean and how is it done?
I've seen a pseudo code for this in Ed Roman's Mastering EJBs, second edition, but I can't seem to get it to work (pages: 330 - 1:1 using CMP and 339 - fake M:N using CMP).
I'm using SUN ONE Application Sever 7. Is this server capable of this?
I'm trying to implement a fake M:N relationship using 3 beans: 2 for each side of the relationship and one as the "bridge" table.
For example, the two beans on each side of the relationship are SubscriberBean, SubscriptionBean and the "bridge: bean is SubscriberSubscriptionBean. The SubscriberSubscriptionBean has two fields: SubscriberLocal stub and SubscriptionLocal stub.
Please let me know if you need more information to answer this question.
Thanks.
Nikola

Im sorry but i dont know about the example you are talking about. I kinda learn
all those techniques from forums, articles and tutorials because book often suffer from
not having the information im mostly looking for.
As far as i understand you, you want to implement a bridge been, which is representing a row in a join table. So that if one side of the relation is deleted the join-table entry (your bridge-CMP-Bean) is cascaded. Right?
First of all the simple part: (My approach)
- The joint table is foreign keys only - without a relation description. -
In this case you dont have to implement a bridge bean. Because it just wouldnt represent anything of sense.
Lets think of an entity/table USER whith the columns name (PRIMARY KEY), and prename.
Our second entity/table is ADDRESS with the columns road (PRIMARY KEY) and housenr.
The join table is simply: USER_ADDRESS with fk_name (FOREIGN KEY) and fk_road (FOREIGN KEY) both on CASCADE DELETE. So if the address is deleted the mapping entry is deleted, too same for the user part:
USER -> USER_ADDRESS <- ADDRESS.
Our entity Beans are called User and Address in class-names JNDI-names and names.
Now we want to create the CMR mapping so we can access the addresses of a user from the user bean directly. The methods on the user side are:
public abstract Collection getAddresses();
and
public abstract void setAddresses(Collection new_addresses);
the xdoclet comments on the User side are (for the getter only)
* @ejb.interface-method
* @ejb.relation
*                name = "User-has-Addresses"
*                role-name = "User-Addresses"
*                target-ejb = "Address"
*                target-multiple = "true"
* @sunone.relation
*                column="USER_ADDRESS.fk_name"
*                target="USER_ADDRESS.fk_road"
public abstract Collection getAddresses();
for the other side of the relation we define in the Address-Entity
public abstract Collection getUsers();
and
public void setUsers(Collection users);
the xdoclet comments on the Address side are (for the getter only)
* @ejb.interface-method
* @ejb.relation
*                name = "User-has-Addresses"
*                role-name = "Address-User"
*                target-ejb = "User"
*                target-multiple = "true"
* @sunone.relation
*                target="USER_ADDRESS.fk_road"
*                column="USER_ADDRESS.fk_name"
As we dont want the user or address to be deleted if the other side of the relation is deleted we dont specify cascade-delete="yes" in the ejb.relation namespace.
The sun-cmp-mappings.xml should now look like this:
(For the User - side)

<cmr-field-mapping>
<cmr-field-name>addresses</cmr-field-name>
<column-pair>
<column-name>USER_ADDRESS.fk_name</column-name>
<column-name>USER_ADDRESS.fk_road</column-name>
</column-pair>
</cmr-field-mapping>
and similar on the Address-Side:
<cmr-field-mapping>
<cmr-field-name>users</cmr-field-name>
<column-pair>
<column-name>USER_ADDRESS.fk_road</column-name>
<column-name>USER_ADDRESS.fk_name>/column-name>
</column-pair>
</cmr-field-mapping>
Dont forget that all elements in the Collection must be of the right Interface-type.
First of all the harder part:
Now what you might want is when the relation has some information specified like user live at address and is tenant or facility manager.
The, in the first step you will have to implement the UserAddressRelation entity which will have to CMR fields of the 1:N type.(Just as you wish)
Lets think of the example above extended by the relation type. Our relation bean is named UserAddressRelation.
Now User has the methods as above but the classes in the Collection must now be of the UserAddressRelationLocal/Remote interface and not AddressLocal/Remote-interface.
You will have to change the xdoclet comment to:
* @ejb.interface-method
* @ejb.relation
*                name = "User-has-Addresses"
*                role-name = "User-Address"
*                target-ejb = "UserAddressRelation"
*                target-multiple = "true"
* @sunone.relation
*                target="USER_ADDRESS.fk_name"
*                column="USER.name"
So we now dont reference the other side bean directly. We reference the relation EntityBean. Do the similar changes on the other side.
In particular you will have to specify 4 CMR mappings now:
1. User to UserAddressRelation 1:N
2. UserAddressRelation N:1
3. Address to UserAddressRelation 1:N
4. UserAddressRelation N:1
Which i dont want to explain in detail now because its kinda all the same as above.
Now you cann access the Addresses of a user in the way.
UserLocal.getAddresses(); <- !you get the mappings!
UserLocal.getAddresses().item(0).getAddress() <- you get the address (this is dirty coding just for understanding)
UserLocal.getAddresses().item(0).getUserRole() <. you get the role of the user at this address.
Hope this helped you. You are welcome to ask any detailed question.

How to make a session bean interact with a entity bean?

hi,
An entity bean has been created and tested successfully. Values entered into the test app are successfully entered into the pointbase db.
Now trying to create the same feature through session beans. when the method is invoked, it appears ok, but when the database is queried the values have not been entered. Is there anything that could have been missed or incorrect?
the steps to setting up session bean
1)add code to create for JNDI lookup
public void ejbCreate() {
System.out.println("Entering oneManagerEJB.ejbCreate()");
Context c = null;
Object result = null;
if (this.myoneHome == null) {
try {
c = new InitialContext();
result =
c.lookup("java:comp/env/ejb/one");
myoneHome =
(oneHome)javax.rmi.PortableRemoteObject.narrow(result,
oneHome.class);
catch (Exception e) {System.out.println("Error: "+
e); }
2) add business method to enter values into entity bean
public void createone(int number) {
System.out.println("Entering ");
try {
one oneinfo =
myoneHome.create(number);
} catch (Exception e) {
// Join the following two lines in the Source Editor
System.out.println("Error in " + e);
// Join the following two lines in the Source Editor
System.out.println("Leaving ");
3) declare variables and namings
import javax.naming.*;
private oneHome myoneHome;
4) add reference to logical session bean
ejb/one
5) create test app and add entity bean "one" to module. check mappings.
run app

I would do several things which will help track down the problem:
1. Where you have println statements you may want to change these to exceptions, the session bean won't really work if these problems occur and may silently fail. For example, throw a runtime exeption or EJBException to indicate that the entity bean home interface cannot be found.
2. When you create the test application you should replace the ejb module which is automatically created with the ejb module or module(s) containing both of the ejb's. This will ensure that the configuration is preserved. The test application is a standard J2EE application, so modules can be added (you could even have multiple test applications each testing a different ejb, make sure that you use different context roots).
Chris

CMP Entity Beans and multiple tables

Hi All,
Is it possible to have a CMP Entity Bean retrieve attributes from multiple tables
(using table join), and populate attributes from columns in both tables?
If yes, how do we configure the same in configuration xml files.
Is there any special handling required for this in the bean itself?
Thanks,
Prabh

Hi All,
Is it possible to have a CMP Entity Bean retrieve attributes from multiple tables
(using table join), and populate attributes from columns in both tables?
If yes, how do we configure the same in configuration xml files.
Is there any special handling required for this in the bean itself?
Thanks,
Prabh

Help:How to manage relationships in CMP Entity beans

Hi everybody;
I am using Oracle JDeveloper 9i release 2 and Oracle 9i database.
How can I manage one-to-many and many-to-many relationships in a CMP Entity Bean, I tried to managed the relationships in code, calling the beans, searching for records, making loops and joining.
Is there a better way to manage the relationships with out doing this in code?
Because I think it is not good for performance.
Regards Francisco

public void selectCurriculum(ValueChangeEvent event){
logger.info(event.getNewValue().getClass());
Integer id = (Integer) event.getNewValue();
Collection curriculums = curriculums().getCurriculums();
ObjectCurriculum curriculum = null;
for (Iterator iterator = curriculums.iterator(); iterator.hasNext();) {
ObjectCurriculum objectCurriculum = (ObjectCurriculum) iterator.next();
if(objectCurriculum.getId().equals(id)){
curriculum = objectCurriculum;
break;
curriculum().setWholeObject(curriculum);
logger.info("setting current curriculum");
no message is logged

BC4J DAOs vs. Local Entity Beans

We are beginning a brand new project and trying to evaluate the costs/benefits of using BC4J entity objects versus local entity beans for our persistence needs.
I've read the "Simplifying J2EE and EJB Development with BC4J" white paper including the "How Does EJB 2.0 Change the Picture?" section, but that seems to have been written at a time when EJB 2.0 support was a rarity.
I'd like to get some feedback from people who have had experience with both. We are basically starting this application from scratch, although we have relational tables from our legacy C++ application that will serve as the basis for the Java object model. So what would we gain/lose by using entity objects?
I must admit, I'm leaning toward using entity beans over a vendor-specific persistence framework, but if there are compelling reasons to choose entity objects (besides those mentioned in the white paper), I'd like to hear them. Please speak slowly, as I'm new to BC4J. :)
Thanks for your time.

I've read the "Simplifying J2EE and EJB Development with BC4J" white paper including the "How Does EJB 2.0 Change the Picture?" section, but that seems to have been written at a time when EJB 2.0 support was a rarity.IMO there's no change.
What Sun doesn't tell you in the specs, but is much talked about on theserverside.com and in most
anti-patterns threads, and in the up coming book J2EE Anti-Patterns; EJB Entities are basically
broke with no solution. Reason: EjbStore() can throw an exception due to DB constraint violation
after the business method returns. This drives the scenario where all business integrity is
forced up into the middle tiers (EJB and business mediator tiers). etc etc ... EJB Entities are
useful for the 5% to 1% of a business model and application that is transactional IMO.
I.E. 95%++ of most apps/web sites are read only. Why use a heavy and expensive transactional
component for reading rows from a DB to be displayed on an Inventory screen? The only reason
to do this is if you have stock in Sun and your appserver vendor or want your project to last
forever or get canceled. -- Seriously, do your home work, using Entities as your persistance
tier mediator, for the 95% of your project that's read only, and for reports which involve
joins, select criteria etc etc will be a serious problem to just code and even bigger problem
to be responsive and scalable.
Do this experiment: implement a report that joins several tables, selects on where criteria,
orders by some attribute in EJB Entity bean technology. Seriously try to code this solution.
Hint: spray water on your appserver box since it'll almost explode. :)
Then try: do the same report in SQL. One SQL statement usually will do it and it's all in the
DB. The data returned to the middle tier is ready for JSP formating.
Try another EJB experiment: implement a finder based on criteria that returns a Collection.
Do the same in SQL: time the perf difference.
Hint: Maybe you're getting the picture, that EJB Entity 2.0 --> 10.0 what-ever, never wrote into
the specs any means for joins, or high perf finders based on criteria.
My opinion and experience: EJB Entity is good for one portion of a project if that; the single
part that's transactional (usually the shopping cart or similar). All other data access needs
to be through a DAO tier that's SQL based. With BC4J you get transactional support too, so
why bother with EJB, except to be wrapped by SLSB's for remotability from the client.
I'd like to get some feedback from people who have had experience with both. We are basically starting this application from scratch, although we have relational tables from our legacy C++ application that will serve as the basis for the Java object model. So what would we gain/lose by using entity objects? I'm at the end of phase one of a medium scale BC4J project which was initiated after scrapping
a Sun Blueprint J2EE 1.2 architecture for the above reasons, plus the unmentioned time to market
issue. We found hand coding the Sun architecture to be 400% slower, if you don't hit any of the
above mentioned bumps in the road. We never got to reports, which would have been imposible without
custom DAOs.
I must admit, I'm leaning toward using entity beans over a vendor-specific persistence framework, but if there are compelling reasons to choose entity objects (besides those mentioned in the white paper), I'd like to hear them. Please speak slowly, as I'm new to BC4J. :)You're not the first to ask this question nor the last. Sun's happy talk in the face of their
king has great cloths sell job to fend off .net will take more than just J2EE Anti-patterns books
to displell. Try the reports and finders experiements in EJB 2.0. You'll no doubt learn alot
and read more news group posts in the process.
Heck, you might even discover that 903 oc4j's CMR and EQL can instantiate 1000's of Entity beans,
JNDI entries, return a Collection of handles, your client get the ValueObjects and build a report
in less than a minute and 100's of customers can do this simultanteously. __NOT__ :)
Cheers,
curt

Explaining Entity Beans

i'm a student. i've just stepped into EJB. I find difficult to learn & deploy Entity beans in J2EE server.
Plz help me to learn the functions, deployment procedures & other JDBC related issues to learn for entity bean deployment

I doubt anyone here is able to give you complete entity bean tuition;) The area is big and you must separate it into smaller parts to learn.
But you can start with the easier parts, step by step with the tutorial. Maynbe as a starter with stateless session beans(I find them easier to understand), for example a bean that will answer a "Hallo world" request, then deploy it (initially with the deploytool, later you will learn how the deployment descriptors should look like).
After that you can play with JDBC from standalone application, not EJBs, and after you feel comfortable with those you can go further, join the technologies.

Entity bean (ejb 3.0) refactoring problem

I didn't find a better method than regenerating an entity bean after modifying the table definition and renaming the class after deleting the old one.
I'm not sure i can delete the old class representing the entity bean before regenerating it without any effects into the others entity beans.
It work fine but still a little problem. The refactoring process didn't change the name of the entity bean into the select clauses into queynamed injection.

I am facing a similar problem. Does JDeveloper 10g (10.1.3.3.0) provide an automatic process to update an Entity Bean definition when the underlying database table definition changes?
I also noticed that for JDeveloper to create all the relationships (i.e. @OneToMany, @ManyToOne) between multiple Entity beans, I need to create all the Entity beans together in one pass using the wizard. If two entities depend on each other, and not created together, JDeveloper will not create the relationships between them. Is there a way around that?
Thank you

Error While Deploying A CMP Entity Bean With A Composite Primary Key

Hello all,
I have a problem deploying CMP Entity beans with composite primary keys. I have a CMP Entity Bean, which contains a composite primary key composed of two local stubs. If you know more about this please respond to my post on the EJB forum (subject: CMP Bean Local Stub as a Field of a Primary Key Class).
In the mean time, can you please tell me what following error message means and how to resolve it? From what I understand it might be a problem with Sun ONE AS 7, but I would like to make sure it's not me doing something wrong.
[05/Jan/2005:12:49:03] WARNING ( 1896):      Validation error in bean CustomerSubscription: The type of non-static field customer of the key class
test.subscription.CustomerSubscriptionCMP_1530383317_JDOState$Oid must be primitive or must implement java.io.Serializable.
     Update the type of the key class field.
     Warning: All primary key columns in primary table CustomerSubscription of the bean corresponding to the generated class test.subscription.CustomerSubscriptionCMP_1530383317_JDOState must be mapped to key fields.
     Map the following primary key columns to key fields: CustomerSubscription.CustomerEmail,CustomerSubscription.SubscriptionType. If you already have fields mapped to these columns, verify that they are key fields.Is it enough that a primary key class be serializable or all fields have to implement Serializable or be a primitive?
Please let me know if you need more information to answer my question.
Thanks.
Nikola

Hi Nikola,
There are several problems with your CMP bean.
1. Fields of a Primary Key Class must be a subset of CMP fields, so yes, they must be either a primitive or a Serializable type.
2. Sun Application Server does not support Primary Key fields of an arbitrary Serializable type (i.e. those that will be stored
as BLOB in the database), but only primitives, Java wrappers, String, and Date/Time types.
Do you try to use stubs instead of relationships or for some other reason?
If it's the former - look at the CMR fields.
If it's the latter, I suggest to store these fields as regular CMP fields and use some other value as the PK. If you prefer that
the CMP container generates the PK values, use the Unknown
PrimaryKey feature.
Regards,
-marina

To use Entity Bean or Oracle stored Package?

Currently, in my project, Weblogic8.1 and Oracle is used, but lots of business logic is implemented using Oracle stored Packages, many of these packages have a package level readonly lookup table(like index-by table or nested table), which is populated with data from database, once the package is called, and is accessed very often in subsequent calls of stored procedures.
Since, in Weblogic server, a connection pool is maintained, and those package level lookup tables would be stored as session data in oracle PGA, I'm afraid this might cause oracle database server to be overloaded.
to fully take advantage of middleware cache service that weblogic provide, should I move those business logic out of oracle and implement them using like read only entity bean?
any help appreciated!

Its very hard to say without knowing the usage patterns of the data. It sounds like you have a lot of read-only entities. These could be spread around a WLS cluster, therefore there is more scalability and performance with this option. However, I would not neccessarily rewrite business logic from SP into EJB just for middle-tier caching.
If its a DB intensive app with lots of SQL, then if the calls are within SP's, there is only 1 call from WLS and the DBA ought o be able to tune the DB usin read-ahead and other DBA semantics. If there is locality of reference in the data, again, DB can use read-ahead better than WLS, although RO cache in middle is more scalable than DBMS.
I wouldnt rewrite business logic from SP to EJB/Entity beans to take advantage of cache, especially if there is no locality of read-only reference to data. Oracle could do this better in my opinion, especially if SP's already exist
Need for information on the usage patterns of the data - how is it CRUD'd.
I would use-case the steel threads and put them under test load to see if the SP's really are an issue, since this is an architecture decision. What state is the project at? Live/Dev? Inception?

Multiple create methods of entity beans in single transcation

Hi,
I have some entity beans with CMR. I am managing these entity beans with a Stateful session bean whose transaction type is Container Managed for all its methods.
In one particular method of this Session bean I am calling two entity bean's create method. i.e I am creating two entity beans through home.create() methods. There are two home.create() methods one after another inside a try catch block.
I want that the entire operation be under just one transcation so i have also given the transaction attribute as Required for all methods of Session bean and Entity Beans.
However if i pass invalid parameters to second create method so that it generates exception then still the first create statement is successful and database is updated.
what i want is that the first create also should be roll backed.
How can i acheive this through Container Managed Transaction Session Bean?

Hi Ashwini,
"Ashwini" <[email protected]> wrote in message news:400291af$[email protected]..
I have some entity beans with CMR. I am managing these entity beans with a Stateful session bean whose transactiontype is Container Managed for all its methods.
>
In one particular method of this Session bean I am calling two entity bean's create method. i.e I am creatingtwo entity beans through home.create() methods. There are two home.create() methods one after another inside a try catch
block.
>
I want that the entire operation be under just one transcation so i have also given the transaction attribute asRequired for all methods of Session bean and Entity Beans.
>
However if i pass invalid parameters to second create method so that it generates exception then still the firstcreate statement is successful and database is updated.
what i want is that the first create also should be roll backed.
How can i acheive this through Container Managed Transaction Session Bean?o Do you use TXDatasource with your entity beans?
o In CMT transactions are automatically rolled back only when RuntimeExceptions
are thrown. What kind of exception is thrown in your case?
Regards,
Slava Imeshev

Timeout of session / entity bean

Hi all
We are facing "RollbackException: The transaction has been marked for rollback (timed out)" excpetion. please help us in resolving this.
Here is problem description.
Code Description:
Step1: Action class calls Session bean
Step2:Session Bean does three things
A. Reads various value from database and write it to fileOutputStream
B. Generate a Sequence number using Sequence
C. Call create method of Entity Bean by local reference to insert the created file (in step 2A) in database as blob
As per our observation session bean takes around 20-30 sec in processing 2A and 2B.
But at 2-C, code raises following error
TariffDocumentBlob is the Entity Bean
TariffSessionEJB is the Session Bean
javax.ejb.CreateException: Error creating EntityBean: RollbackException: The transaction has been marked for rollback (timed out)
05/10/24 16:04:01      at TariffDocumentBlobLocalHome_EntityHomeWrapper397.create(TariffDocumentBlobLocalHome_EntityHomeWrapper397.java:1135)
05/10/24 16:04:01      at com.derc.rims.businessservice.businessinterface.TariffSessionEJBBean.createTariffBlobMasterRecord(TariffSessionEJBBean.java:102)
05/10/24 16:04:01      at com.derc.rims.businessservice.businessinterface.TariffSessionEJBBean.uploadTariff(TariffSessionEJBBean.java:76)
05/10/24 16:04:01      at TariffSessionEJBLocal_StatelessSessionBeanWrapper96.uploadTariff(TariffSessionEJBLocal_StatelessSessionBeanWrapper96.java:80)
05/10/24 16:04:01      at com.derc.rims.businessservice.businessinterface.BISessionFacadeEJBBean.delegate(BISessionFacadeEJBBean.java:534)
05/10/24 16:04:01      at BISessionFacadeEJB_StatelessSessionBeanWrapper4.delegate(BISessionFacadeEJB_StatelessSessionBeanWrapper4.java:101)
05/10/24 16:04:01      at com.derc.rims.action.tariff.CalculateTariffAction.execute(CalculateTariffAction.java:75)
05/10/24 16:04:01      at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
05/10/24 16:04:01      at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
05/10/24 16:04:01      at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1485)05/10/24 16:04:01      at
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:527)05/10/24 16:04:01      at
javax.servlet.http.HttpServlet.service(HttpServlet.java:760)05/10/24 16:04:01      at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)05/10/24 16:04:01
at com.evermind.server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:65)05/10/24 16:04:01      at
oracle.security.jazn.oc4j.JAZNFilter.doFilter(Unknown Source)05/10/24 16:04:01      at
com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:649)05/10/24 16:04:01      at
com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:322)05/10/24 16:04:01 TRANSACTION OVER05/10/24
16:04:01      at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:790)
05/10/24 16:04:01      at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:270)
05/10/24 16:04:01      at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)
05/10/24 16:04:01      at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)
05/10/24 16:04:01      at java.lang.Thread.run(Thread.java:534)
com.evermind.server.rmi.OrionRemoteException: Transaction was rolled back: timed out     at
BISessionFacadeEJB_StatelessSessionBeanWrapper4.delegate(BISessionFacadeEJB_StatelessSessionBeanWrapper4.java:159)
at com.derc.rims.action.tariff.CalculateTariffAction.execute(CalculateTariffAction.java:75)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1485)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:527)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.evermind.server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:65)
at oracle.security.jazn.oc4j.JAZNFilter.doFilter(Unknown Source)
at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:649)
at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:322)
at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:790)
at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:270)
at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)
at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)
at java.lang.Thread.run(Thread.java:534)
     Nested exception is:java.rmi.RemoteException: No Exception - originate from:java.lang.Exception: No Exception - originate from:; nested exception is:
     java.lang.Exception: No Exception - originate from:     at com.evermind.server.ejb.EJBUtils.makeException(EJBUtils.java:931)
     at BISessionFacadeEJB_StatelessSessionBeanWrapper4.delegate(BISessionFacadeEJB_StatelessSessionBeanWrapper4.java:159)
     at com.derc.rims.action.tariff.CalculateTariffAction.execute(CalculateTariffAction.java:75)
     at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
     at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
     at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1485)
     at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:527)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
     at com.evermind.server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:65)
     at oracle.security.jazn.oc4j.JAZNFilter.doFilter(Unknown Source)
     at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:649)
     at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:322)
     at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:790)
     at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:270)
     at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)
     at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)
     at java.lang.Thread.run(Thread.java:534)
     Caused by: java.lang.Exception: No Exception - originate from:     at com.evermind.server.ejb.EJBUtils.makeException(EJBUtils.java:930)
     ... 17 more
We have tried out .....
- Making new Enity Bean
- changing timeout of session bean by changing it in properties
<session-deployment name="TariffSessionEJB" timeout="300" >
We are using Oracle 10g application Sever and Oracle 10.1 database.

Assuming you are using either 9.0.4 or 10.1.2, please note that default transaction time out is 30s and you can change that <transaction-config> element in server.xml. This is specified in millliseconds
-Debu

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