Can EJB 1.1 and EJB 2.0 Coexists ?

Can EJB 1.1 and EJB 2.0 Coexists.
We have an Application in EJB 1.1. We want to shift to EJB2.0.
Do we need to change all the EJBs in one go or can we change one by one, the 2 versions existing together in the same EAR file ? We are using Weblogic 6.1.

Migrating from Enterprise JavaBeansTM (EJBTM )1.1 to 2.0
http://developer.java.sun.com/developer/technicalArticles/ebeans/ejbmigrate/

Similar Messages

EJB 2.0 and EJB 1.1

Hi, I'm porting an application based on J2EE 1.2.1 to J2EE 1.3.1, this application has some "border" EJBs (1.1) that will become 2.0 EJBs and that have to call other 1.1 EJBs (part of another application). Can 2.0 EJBs call 1.1 EJBs ? Aren't all call to remote interfaces (after lookup, narrow, create, etc.) ?
An opinion will be welcome
Roberto

Ejb 1.1 code will run in the container compatible with Ejb 2.0 without any change.
http://developer.java.sun.com/developer/technicalArticles/ebeans/ejbmigrate/

Using JMX to read ejb manifest jar and ejb-jar.xml in ejb jar inside ear

Hello,
I have an ear deployed on weblogic console. I need to check contents of manifest file and ejb-jar.xml of a jar that is present in the deployed ear.
Currently I am using below code to access jar inside ear deployed :
Hashtable env = new Hashtable(5);
env.put(Context.INITIAL_CONTEXT_FACTORY,
"weblogic.jndi.WLInitialContextFactory");
env.put(Context.PROVIDER_URL,
url);
env.put(Context.SECURITY_PRINCIPAL, user);
env.put(Context.SECURITY_CREDENTIALS, password);
Context ctx = new InitialContext(env);
mBeanHome = (MBeanHome)ctx.lookup(MBeanHome.ADMIN_JNDI_NAME);
String type = "EJBComponentRuntime";
Set beans = mBeanHome.getMBeansByType(type);
try{
for(Iterator it=beans.iterator();it.hasNext();)
EJBComponentRuntimeMBean rt = (EJBComponentRuntimeMBean)it.next();
if(rt.getParent().getName().equals("xxx")){
System.out.println(rt.getName());
l.add(rt.getName());
Here xxx is the ear. Now I need to get inside the jar (represented) by variable rt and access its manifest file,ejb-jar.xml
Does anyone have an idea how to do this?
regards
Sameer

Isn't it possible to put them there manually? :)

Can AIA 2.0 and AIA 2.5 coexist?

We have a prior dump from AIA 2.0 over Linux . We intend to now have a new installation of AIA 2.5 over Linux
Can these two versions coexist? is there anything that i need to do?

Hi,
Even I have the AIA2.0 installed on the linux server and now plan to have AIA 2.5 installed. I have used the Order to Bill PIP so far. Will it be possible for both AIA2.0 and AIA2.5 to coexist?

IMovie, can version 10.0 and version 9.0 coexist

My MacMini came with iMovie version 10.0, which I dont like
How can I install iMovie version '09 without removing version 10.0

Sorry, I misread your post. I thought you had iMovie version 9.
iLife '09 came with iMovie '09 which is version 8, not version 9. I don't know if this should instal in Mavericks. iMovie '11 (version 9) came with iLife '11. That definitely works for people who had iMovie 9.0.9 in Mountain lion and then upgraded to Mavericks. The Mavericks instal leaves imovie 9.0.9 in a folder called imovie 9.0.9 in the applications folder. iLife '11 is available from Amazon .
Geoff.

ABAP Objects and EJB

Hi every one,
Can <b>ABAP Objects and EJB</b> be compared?
-Naveen.

Hi Naveen,
Check this guide- might be useful-
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/dc09af90-0201-0010-d09b-bd611a11070b
Regards,
Moorthy

Diff b/w bc4j model and ejb model in adf11g

hi all,
iam murali iam new for adf 11g i have some dout's in adf11g ,can u please solve my probleam
what is the difference b/w bc4j componet and ejb componet,how to develop ejb application in adf11g.

,how to develop ejb application in adf11gTake a look at this tutorial for starters:
http://st-curriculum.oracle.com/obe/jdev/obe11jdev/ps1/ejb/ejb.html

Design problem involving Wildcards and EJB-QL.

Could someone tell me if this is possible? (my syntax might be a bit off, but bear with me. It's the design I'm interested in, not the exact syntax)
signature="java.util.Collection findByFullMonty (java.lang.Float price, java.lang.Integer bedrooms... "*snip*
query="SELECT OBJECT(o) FROM Houses o WHERE ((o.price =?1) AND (o.bedrooms= ?2) AND ... "*snip*I'd like to be able to use this query with wildcards as default values in a fashion similiar to this:
Float price = ?? ;//This is where i'm unsure, what is a valid wildcard for a Float?
Integer bedrooms = ??; // same here for Integer....
String realtorName = "*"; //i think this is valid wildcard for strings
*snip*
//if price supplied set price to input value
if (myObject.getPrice() != null){
price = myObject.getPrice();
//if bedrooms supplied set bedrooms to input value
if (myObject.getBedrooms()!= null){
bedrooms = myObject.getBedrooms();
//always use this finder using wild cards unless a parameter is supplied
Collection c = findByFullMonty (price, bedrooms, realtorName, *snip*); What i'm tyring to achieve is a single query that will work no matter how many of the input paramaters are supplied. Any supplied parameters are used, and those that are not supplied will use wildcard instead. I don't want to make a seperate query for every possible permutaion of supplied input parameters. Can this be done? If so, am I even close or out in left field? Is there a design pattern I should look into for this problem?
Thanks for any help guys!
(sorry for the cross-post, i didn't realize this was the approprate place until afterwards)

Yes, that makes sense, but the EJB-QL statements and finder methods in the home interface have to be defined at deployment time, correct? Once it is deployed, I can't dynamically create the EJB-QL statements and finder methods that are needed. That's the major hurdle I have right now.
Populating a big 'catch-all' query with wild cards and replacing them with supplied literal values is the only way I could think of to accomplish this dynamically. In my current work around I set a flag for each piece of data supplied. I then decide which (pre-defined) query is needed based on the supplied criteria flags. The problem is, I now have to have 2^n (n = number of possible input parameters) permutaions for the possible queries. For example: say i have: price, bedrooms and bathrooms. I'd need queries for the following cases:
1 price supplied only
2 bedrooms supplied only
3 bathrooms supplied only
4 price and bedrooms
5 price and bathrooms
6 bedrooms and bathrooms
7 price, bedrooms, bathrooms
8 nothing supplied (return everything)
Obviously this is going to break down really fast as the number of input parameters climbs.
Should I look at using some kind of JDBC code directly to build a query as I go? It seems like I am either approaching this the wrong way or missing something really obvious.

EJB 3.0 and jndi lookup (simple question)

hi all,
i am newbie on Weblogic Application Server and i have some issues,
i have weblogic application server 10.0, also i have oracle timesten in-memory database, i have configured datasource and deploy my ejb 3.0 application, but i could not done jndi lookup?
here is my example:
1. one stateless session bean :
import javax.ejb.Remote;
@Remote
public interface InsertSubscriber {
     public void insertSubscriber(SubscriberT subscriberT);
} 2. here is it's implementation :
@Remote(InsertSubscriber.class)
@Stateless
public class InsertSubscriberBean implements InsertSubscriber {
     @PersistenceContext(unitName = "TimesTenDS")
     private EntityManager oracleManager;
     public void insertSubscriber(SubscriberT subscriber)
          try {
               System.out.println("started");
               oracleManager.persist(subscriber);
               System.out.println("end");
          } catch (Exception e) {
               e.printStackTrace();
}3 and my test client :
public class Client {
     public static void main(String[] args) {
          Context ctx = null;
          Hashtable ht = new Hashtable();
          ht.put(Context.INITIAL_CONTEXT_FACTORY,
                    "weblogic.jndi.WLInitialContextFactory");
          ht.put(Context.PROVIDER_URL, "t3://192.9.200.222:7001");
          try {
               ctx = new InitialContext(ht);
               InsertSubscriber usagefasade = (InsertSubscriber) ctx
                         .lookup("ejb.InsertSubscriberBean");
          } catch (NamingException e) {
               e.printStackTrace();
          } finally {
               try {
                    ctx.close();
               } catch (Exception e) {
                    e.printStackTrace();
}what i did incorrect ???
i got error like this : Name not fount exception
when i tried to view jndi tree on weblogic server application console i found this :
     Binding Name:
TimestenExampleTimestenExample_jarInsertSubscriberBean_InsertSubscriber
     Class:
test.InsertSubscriberBean_o7jk9u_InsertSubscriberImpl_1000_WLStub
     Hash Code:
286
     toString Results:
weblogic.rmi.internal.CollocatedRemoteRef - hostID: '2929168367193491522S::billing_domain:AdminServer', oid: '286', channel: 'null'what does it mean how i can done lookup to jndi ?
Regards,
Paata Lominadze,
Magticom LTD.
Georgia.

Hi All,
I am using the weblogic cluster with session replication and EJB 2.0 with Local entity beans.
for fail-over session should be replicated to another server so we can achive the same session if 1st server fails.
Suppose i m using two managed server(server1,server2) in the cluster.I am storing the object of class ABC into session and object contains the instance of Local-EntityBean home but i put that as a transient.I have also override the readObject and write object method.
when write object is called on 1st server,readObject method should be called on second server so we will be sure that session is replicating properly.
pleaase find the code below : -
public IssuerPageBean() {
initEJB();
private void readObject(java.io.ObjectInputStream stream) throws IOException, ClassNotFoundException {
stream.defaultReadObject();
initEJB();
initializeCommonObject();
private void writeObject(java.io.ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
private void initEJB() {
try {
ic = new InitialContext();
issuerHome = (LocalIssuerHome) ic.lookup("java:comp/env/Issuer");
} catch (NamingException e) {
e.printStackTrace();
in my case if i am calling the constructor IssuerPageBean(),it calls the initEJB() method and lookeup the entity local home properly but when readObject method is called on another server only initEJB() method is called directly and getting the exception below :
WARNING: Error during create -
javax.naming.NameNotFoundException: remaining name: env/ejb/Client
at weblogic.j2eeclient.SimpleContext.resolve(Ljavax/naming/Name;Z)Ljavax/naming/Context;(SimpleContext.java:35)
at weblogic.j2eeclient.SimpleContext.resolve(Ljavax/naming/Name;)Ljavax/naming/Context;(SimpleContext.java:39)
at weblogic.j2eeclient.SimpleContext.lookup(Ljavax/naming/Name;)Ljava/lang/Object;(SimpleContext.java:57)
at weblogic.j2eeclient.SimpleContext.lookup(Ljavax/naming/Name;)Ljava/lang/Object;(SimpleContext.java:57)
at weblogic.j2eeclient.SimpleContext.lookup(Ljava/lang/String;)Ljava/lang/Object;(SimpleContext.java:62)
at weblogic.jndi.factories.java.ReadOnlyContextWrapper.lookup(Ljava/lang/String;)Ljava/lang/Object;(ReadOnlyCont
extWrapper.java:45)
at weblogic.jndi.internal.AbstractURLContext.lookup(Ljava/lang/String;)Ljava/lang/Object;(AbstractURLContext.jav
a:130)
at javax.naming.InitialContext.lookup(Ljava/lang/String;)Ljava/lang/Object;(InitialContext.java:347)
at com.lb.equities.veda.tools.salesvault.jsp.ClientPageBean.initEJB()V(ClientPageBean.java:218)
at com.lb.equities.veda.tools.salesvault.jsp.ClientPageBean.readObject(Ljava/io/ObjectInputStream;)V(ClientPageB
ean.java:191)
at java.lang.LangAccessImpl.readObject(Ljava/lang/Class;Ljava/lang/Object;Ljava/io/ObjectInputStream;)V(Unknown
Source)
at java.io.ObjectStreamClass.invokeReadObject(Ljava/lang/Object;Ljava/io/ObjectInputStream;)V(Unknown Source)
at java.io.ObjectInputStream.readSerialData(Ljava/lang/Object;Ljava/io/ObjectStreamClass;)V(Unknown Source)
at java.io.ObjectInputStream.readOrdinaryObject(Z)Ljava/lang/Object;(Unknown Source)
at java.io.ObjectInputStream.readObject0(Z)Ljava/lang/Object;(Unknown Source)
at java.io.ObjectInputStream.readObject()Ljava/lang/Object;(Unknown Source)
at java.util.HashMap.readObject(Ljava/io/ObjectInputStream;)V(Unknown Source)
at java.lang.LangAccessImpl.readObject(Ljava/lang/Class;Ljava/lang/Object;Ljava/io/ObjectInputStream;)V(Unknown
Source)
at java.io.ObjectStreamClass.invokeReadObject(Ljava/lang/Object;Ljava/io/ObjectInputStream;)V(Unknown Source)
at java.io.ObjectInputStream.readSerialData(Ljava/lang/Object;Ljava/io/ObjectStreamClass;)V(Unknown Source)
at java.io.ObjectInputStream.readOrdinaryObject(Z)Ljava/lang/Object;(Unknown Source)
at java.io.ObjectInputStream.readObject0(Z)Ljava/lang/Object;(Unknown Source)
at java.io.ObjectInputStream.defaultReadFields(Ljava/lang/Object;Ljava/io/ObjectStreamClass;)V(Unknown Source)
at java.io.ObjectInputStream.readSerialData(Ljava/lang/Object;Ljava/io/ObjectStreamClass;)V(Unknown Source)
at java.io.ObjectInputStream.readOrdinaryObject(Z)Ljava/lang/Object;(Unknown Source)
at java.io.ObjectInputStream.readObject0(Z)Ljava/lang/Object;(Unknown Source)
at java.io.ObjectInputStream.readObject()Ljava/lang/Object;(Unknown Source)
at weblogic.common.internal.ChunkedObjectInputStream.readObject()Ljava/lang/Object;(ChunkedObjectInputStream.jav
a:120)
at weblogic.rjvm.MsgAbbrevInputStream.readObject(Ljava/lang/Class;)Ljava/lang/Object;(MsgAbbrevInputStream.java:
121)
at weblogic.cluster.replication.ReplicationManager_WLSkel.invoke(ILweblogic/rmi/spi/InboundRequest;Lweblogic/rmi
/spi/OutboundResponse;Ljava/lang/Object;)Lweblogic/rmi/spi/OutboundResponse;(Unknown Source)
at weblogic.rmi.internal.BasicServerRef.invoke(Lweblogic/rmi/extensions/server/RuntimeMethodDescriptor;Lweblogic
/rmi/spi/InboundRequest;Lweblogic/rmi/spi/OutboundResponse;)V(BasicServerRef.java:492)
Please help .
Thanks in Advance.
Edited by hforever at 03/04/2008 7:28 AM

EJB 3.0 AND Eclipse

Hi,
I'm looking for a good tutorial on eclipse and ejb 3.0. I started using the book Beginning Java EE 5: From Novice to Professional:
http://www.apress.com/book/view/1590594703
however I have come across a problem. I cant seem to get the example for a setting up a simple stateless session bean running. I'm using eclipse so I thought I could refer to this tutorial on eclipse;
http://www.eclipse.org/webtools/community/tutorials/ejbtutorial/buildingejbs.html
however this tutorial seems to be using a different version of eclipse or wtp and as a result it has many different options. I'm left a bit uncertain as to what I'm supposed to do to build an EJB.
Can someone give me an extremely simple example of creating a stateless session bean in EJB 3.0?

Check this one:
http://www.webagesolutions.com/knowledgebase/javakb/jkb005/index.html

EJB 3.0 @Stateless @EJB @Resource and JNDI clarity..

Hi,
I am trying to configure an EJB 3.0 but not able to do so properly.
I have a single business interface and 2 bean implementation class of the same business interface doing different things. How do I access the EJB's if I have the same business interface class.I am getting JNDI error while trying to lookup.
Also what does the "name" and "mappedName" in @Stateless(name ="...",mappedName="") signify.
Then in case of Dependency injection,how should I look for the EJB? What would be it's JNDI name in this case?
@EJB(name="",beanName="",mappedName="")
private HelloEJB hello;
What does the name,benaName and mappedName in case of an @EJB annotation signify??
Please clear me with these attributes of @Stateless and @EJB and @Resource. I am getting toatlly confused with what should be the logic name and what is the JNDI name????
Thanks

In @Stateless, @name() is the annotation equivalent of <ejb-name> in ejb-jar.xml. It gives a unique bean name identifier to the component within the ejb-jar. It is completely independent of mappedName. If no @Stateless name() is specified, it defaults to the unqualified bean class name.
In @Stateless, mappedName() is used to assign a global JNDI name to the bean's remote interface. This can be used to explicitly lookup the EJB reference to that interface or as one way to resolve a caller's EJB dependency.
In @EJB, if the target of the dependency lives within the same application, you can always fully resolve it using only beanName(). beanName() takes the value specified in @Stateless name(), or the default as described above.
@EJB name() assigns a name to the client dependency within the caller's component environment. It is optional. In most cases that value doesn't matter since if the dependency is being injected you never have to refer to the name() attribute anywhere else.
@EJB mappedName() is used to resolve an EJB dependency that spans applications. It holds a global JNDI name, e.g. the one specified in @Stateless mappedName(). mappedName() is not required to be supported by all vendors.
So, to sum it all up, it's fine to have two different beans that expose the same interface. E.g. :
@Stateless(name="A1", mappedName="A1Global")
public class A1 implements A { ... }
@Stateless(mappedName="A2Global") // name() defaults to "A2"
public class A2 implements A { ... }
In a caller within the same application :
@EJB(beanName="A1")
private A a;
@EJB(beanName="A2")
private A a;
In a caller within a different application :
@EJB(mappedName="A1Global")
private A a;
@EJB(mappedName="A2Global")
private A a;
You can find additional information in our EJB FAQ :
https://glassfish.dev.java.net/javaee5/ejb/EJB_FAQ.html#EJB_ejb-ref_ejb_local_ref

Problem with "package-info.java" using EJB 3.0 and OC4J

Hi all.
I already posted this question on JDeveloper forum, but didn't get any answer,
so I'll try posting here.
Anyway, I'm new both to JDeveloper and J2EE,
so I'm trying out examples for EJB 3.0, and I got stuck at "Use Security Annotations with EJB 3.0"
(http://www.oracle.com/technology/tech/java/oc4j/ejb3/howtos-ejb3/howtoejb30security/doc/how-to-ejb30-security-ejb.html).
Example code is working perfectly, if one builds it using Ant, but I'm importing all examples into JDeveloper (or at least I'm trying to :))
JDeveloper can't build file "package-info.java" containing following code:
@javax.annotation.security.SecurityRoles(roleNames={"superuser", "user"})
package oracle.ejb30;I'm getting following output in "Compiler - Log" window:
Error(2,1): 'class', 'interface', or 'enum' expected.
Help much appreciated...
platform used:
Windows XP SP2
JDeveloper Studio (Version 10.1.3, Build 3412)
JDK 1.5_06
OC4J 10.1.3 developer preview 4 (standalone version)

Since you're using EJBs, you can use JTA and can skip the getTransaction() calls. If you want to use getTransaction().begin() and commit(), then make sure that your EntityManager is resource-local. The configuration for this is in persistence.xml. Set a transaction-type of RESOURCE_LOCAL rather than JTA.

JDBC, JMS and EJB transactions - possible problem?

Hello,
          I am using Oracle 9, Weblogic 8.1 SP 4, MyEclipse and
          XDoclet.
          In my current project I have the following piece of code
          in one of my message driven beans (code cited as pseudocode
          without unnecessary details):
          * @ejb.bean name="MyMessageProcessor"
          * display-name="Display name for a MyMessageProcessor"
          * jndi-name="ejb/MyMessageProcessor"
          * description="Bean MyMessageProcessor"
          * destination-type="javax.jms.Queue"
          * transaction-type="Container"
          * acknowledge-mode="Auto-acknowledge"
          * subscription-durability="Durable"
          * generate="false"
          * @ejb.transaction type="Required"
          public class MyMessageProcessor implements MessageDrivenBean, MessageListener {
          public void onMessage(Message msg) {
               try {
                    //obtaining connections to two different databases via JNDi
                    java.sql.Connection connOne =
                    ((DataSource)ctx.lookup("DataSourceOne")).getConnection();
                    java.sql.Connection connTwo =
                         ((DataSource)ctx.lookup("DataSourceTwo")).getConnection();
                    // performing some UPDATEs and INSERTs on connOne and connTwo
                    // calling some other methods of this bean
                    //creating the reply JMS message and sending it to another JMS queue
                    Message msgTwo = this.createReplyMessage(msg)
                    this.queueSender.send(msgTwo);
                    //commiting everything
                    this.queueSession.commit();
               } catch (Exception ex) {
               try {
                    if (this.queueSession!=null) this.queueSession.rollback();
               } catch (JMSException JMSEx) {};
               this.context.setRollbackOnly();
          Some days ago (before the final remarks from my client) there used to be only one DataSource configurated on the basis of the
          connection pool with non-XA jdbc driver. Everything worked fine
          including the transactions (if anything wrong happend not only wasn't the replymessage sent, but also no changes were written
          to database and the incomming message was thrown back to the my bean's
          queue).
          When I deployed the second DataSource I was informed by an error message, that only one non-transactional resource may
          participate in a global transaction. When I changed both datasources
          to depend on underlying datasources with transatcional (XA) jdbc drivers, everything stopped working. Even if
          EJB transaction was theoretically successfully rolledbacked, the changed were written to the database
          and the JMS message wasn't resent to the JMS queue.
          So here are my questions:
               1. How to configure connection pools to work in such situations? What JDBC drivers should I choose?
               Are there any global server configurations, which may influence this situation?
               2. Which jdbc drivers should I choose so that the container was able to rollback the database transactions
               (of course, if necessary)?
               3. Are there any JMS Queue settings, which would disable the container to send message back to the
               queue in case of setRollbackOnly()? How should be the Queue configurated?
          As I am new to the topic and the deadline for the project seems to be too close I would be grateful
          for any help.
          This message was sent to EJB list and JDBC list.
          Sincerely yours,
          Marcin Zakidalski

Hi,
          I found these information extremely useful and helpful.
          The seperate transaction for sending messages was, of course, unintentional. Thanks a lot.
          Anyway, I still have some problems. I have made some changes to the
          code cited in my previous mail. These changes included changing QueueSessions
          to non-transactional. I also set the "Honorate global transactions" to true.
          I am using XA JDBC driver. After setting "Enable local transactions" to false
          (I did it, because I assume that JDBC transactions should be part on the global
          EJB transaction) I got the following error:
          java.sql.SQLException: SQL operations are not allowed with no global transaction by default for XA drivers. If the XA
          driver supports performing SQL operations with no global transaction, explicitly allow it by setting
          "SupportsLocalTransaction" JDBC connection pool property to true. In this case, also remember to complete the local
          transaction before using the connection again for global transaction, else a XAER_OUTSIDE XAException may result. To
          complete a local transaction, you can either set auto commit to true or call Connection.commit() or Connection.rollback().
          I have also inspected the calls of methods of bean inside of onMessage() method just to check, whether
          the transactions are correctly initialized (using the weblogic.transaction.Transaction class).
          My questions are as follows:
          1. Any suggestions how to solve it? I have gone through the google answers on that problem and only
          thing I managed to realize that JDBC must start its own transaction. Is there any way to prohibit it
          from doing that? Can using setAutocommit(true/false) change the situation for better?
          2. How to encourage the JDBC driver to be a part of EJB transaction?
          3. As I have noticed each of ejb method has its own transactions (transactions have different
          Xid). Each method of the bean has "required" transaction attribute. Shouldn't it work in such
          way that if already started transaction exists it is used by the called method?
          4. The DataSources are obtained in my application via JNDI and in the destination environment I will have slight
          impact on the configuration of WebLogic. What is least problematic and most common WebLogic configuration which would
          enable JDBC driver to participate in the EJB transaction? Is it the WebLogic configuration problem or can it be
          solved programmically?
          Currently my module works quite fine when "enable local transactions" for DataSources is set to true, but this way
          I am loosing the ability to perform all actions in one transaction.
          Any suggestions / hints are more than welcomed. This message was posted to jdbc list and ejb list.
          Marcin

Ejb 3.0 and JDeveloper

If I drag and drop tables with One to one mapping in an ejb diagram in JDeveloper (one table have having the foreign key as the primary key). If I create ejb 2.1 beans it makes makes a One To One mapping between the entity beans created and if I drop them as ejb 3.0 it makes a OneToMany mapping. this is what I get for the same tables.
for ejb 2.1
<ejb-relation>
<ejb-relation-name>Envincidents - Incidents</ejb-relation-name>
<ejb-relationship-role>
<ejb-relationship-role-name>Envincidents has one Incidents</ejb-relationship-role-name>
<multiplicity>One</multiplicity>
<relationship-role-source>
<ejb-name>Envincidents</ejb-name>
</relationship-role-source>
<cmr-field>
<cmr-field-name>incidents_incidentsId</cmr-field-name>
</cmr-field>
</ejb-relationship-role>
<ejb-relationship-role>
<ejb-relationship-role-name>Incidents may have one Envincidents</ejb-relationship-role-name>
<multiplicity>One</multiplicity>
<relationship-role-source>
<ejb-name>Incidents</ejb-name>
</relationship-role-source>
</ejb-relationship-role>
</ejb-relation>
for ejb 3.0
Envincidents
@Id
@ManyToOne(targetEntity="mypackage.Incidents")
@JoinColumn(name="ENVINCIDENTS.INCIDENTS_ID", referencedColumnName="INCIDENTS.ID")
public Incidents getIncidents() {
return incidents;
public void setIncidents(Incidents incidents) {
this.incidents = incidents;
Incidents
@OneToMany(targetEntity="mypackage.Envincidents")
@JoinColumn(name="ENVINCIDENTS.INCIDENTS_ID", referencedColumnName="INCIDENTS.ID")
public Collection<Envincidents> getEnvincidentsCollection() {
return envincidentsCollection;
public void setEnvincidentsCollection(Collection<Envincidents> envincidentsCollection) {
this.envincidentsCollection = envincidentsCollection;
public Envincidents addToEnvincidentsCollection(Envincidents envincidents) {
getEnvincidentsCollection().add( envincidents );
envincidents.setIncidents( this );
return envincidents;
public Envincidents removeFromEnvincidentsCollection(Envincidents envincidents) {
getEnvincidentsCollection().remove( envincidents );
envincidents.setIncidents( null );
return envincidents;
this causes the following problem.
Exception Description: Multiple writable mappings exist for the field [ENVINCIDE
NTS.INCIDENTS_ID]. Only one may be defined as writable, all others must be spec
ified read-only.
which I have already reported.
I know this is a minor inconvenience and I can hand edit the entity beans and make them one to one for ejb 3.0. But would be to good advantage to have a consistent "dropping of tables" for ejb 2.1 and 3.0. So one can have a similar behavior of entity beans created from tables using ejb 2.1 and 3.0.

I guess this could be desirable if migrating from ejb 2.1 to 3.0 if one has already designed the database.
Dev

EJB 3.0 and Struts 1.0

Have a Struts/EJB question...
If I have a web-form backed by an ActionForm in Struts, where the user
types in a record that maps directly to an EJB3 entity class and a
corresponding db-table, is it advisable (or even possible) to somehow
use the same class for the ActionForm and the EJB?
Im thinking the 2 beans, they have basically the same setter/getter
methods,
but the form-bean extends ActionForm, while the Entity class
implements serializable...
Is it possible to use one and the same class for both purposes... or
maybe one extends the other...
Or should they just be two different classes, and have to copy data
back and forth between them?
What is "best practice" here?
Edited by: vb.bajpai on Feb 13, 2009 4:13 AM

Well, the "best practice" is the one that better fits for you. Your idea of making another bean for struts, has been thought before. That technique is called "DTO Pattern". Search the java blueprints for the DTO Pattern.
So you have 2 options
Use EJB entities through all your app
pros: less code to write
cons: highly coupled code. struts must stick to your EJB entity beans.
Use the DTO pattern
pros: loose coupled design. you can change your entities and your struts forms wont be affected.
cons: more code to write. You may need help from a bean to bean mapper like dozer or ezconvert
PS: DTO (Data Transfer Object), VO (Value Object), and TO (Transfer Object) are all synonyms.

Can EJB 1.1 and EJB 2.0 Coexists ?

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