Regarding Entity bean

Does new version of OAS 4.0.8.1 or
JDeveloper 3.0 support Entity Bean .
Can anyone help me?
from Prashant

That blows. I've been really counting on Oracle to come through on at least the EJB 1.1 spec for OAS is not for 8.1.6. At the iSeminar I was informed it was available in beta with the release. This is getting disheartening as IBM has good all-around integrated support for the full standard but I've committed alot of time and energy to the Oracle platform.
Now I need to re-think that decision? That sucks.
Will :-\

Similar Messages

Regarding ENTITY bean local interfaces

Hi all,
I have a component session bean - containing a number of service methods for creating, retrieving, updating & deleting instances of a related entity bean. This session bean is used by another session facade bean, which invokes the various service methods in some sequence to complete a major task.
In the component session bean, the retireve methods return the local interface of the entity bean - on which it operates. The update methods accespt local interfaces of entity bean which can be directly updated.
My question is : Is it a right approach to pass the entity bean instances between method calls.
Thanks in advance,
Baskar

Your pointers regarding pt 2 was nice. Thanks.
This being my first J2ee design, I'am just collecting as much information as possible to stay confident.
Later, I started thinking a bit more regarding pt 1.
Where, I decided using individual session beans for different components(representing unique functionalities).
i.e,, I'am just thinking, should I use individual session beans for each of these different components.
What if I use standard java classes - implementing pre-defined interfaces for each of these components & use the components through these interfaces in session facade.
Now, I'll be using entity bean creates/retrieves/updates/deletes from inside normal java classes.
I thought, this would obviate the need for JNDI lookups - each time I want to use the components in my session facade.
But, I'am not sure of where this will impact..As far as I can visualize, this seems to be normal. Please share ...your thoughts regarding this. (something regarding transactions ??)

Is there a better way of doing this? (regards Entity Beans, CMP, J2EE5...)

Hello everyone,
So I'm going to blurt out two classes of code. First is a plain entity bean and the second is a helper class with two static methods to help me to convert Object into byte[] and vice versa without much worrying.
Now the problem is, how to persist this entity bean and it's two Objects (two Lists) in a more "J2EE5 way". I just need to store these two Objects, or any Serializable Object, into persistent storage. So how to avoid this serialization by-hand that I'm doing... ?
Thank you for your interest - and help :),
Samuli
Maybe using a @Lob notation or such? I've tried, but I can't get it workign. @Lob itself is not enough since it results in casting problems when retrieveing the data back from the persistent storage.
And oh, I'm just using the simple CMP with this.. EJB using EntityManager's persist method to store and so on..
EntityBean class (imports and packages excluded)
@Entity
public class MessageHandlerChain implements java.io.Serializable {
    @TableGenerator(
        name="messageHandlerChainIDGenerator",
        allocationSize=1,
        initialValue=1
    @GeneratedValue(
        generator="messageHandlerChainIDGenerator",
        strategy=GenerationType.TABLE
    @Id
    private Integer messageHandlerChainID;
    @Lob
    private byte[] messageHandlers;
    @Lob
    private byte[] messageHandlerProperties;
    @Transient
    private List<String> messageHandlersObj = new ArrayList<String>();
    @Transient
    private List<Map<String,String>> messageHandlerPropertiesObj = new ArrayList<Map<String,String>>();
     * Constructs an empty instance of <code>MessageHandlerChain</code> without any properties.
    public MessageHandlerChain() {
    public Integer getMessageHandlerChainID() {
        return messageHandlerChainID;
    public void setMessageHandlerChainID(Integer messageHandlerChainID) {
        this.messageHandlerChainID = messageHandlerChainID;
    public List<String> getMessageHandlers() {
        return messageHandlersObj;
    public void setMessageHandlers(List<String> messageHandlersObj) {
        if (messageHandlersObj == null) {
            System.out.println("[MessageHandlerChain] setMessageHandlers() can't be given a null value.");
            return;
        this.messageHandlersObj = messageHandlersObj;
    public List<Map<String,String>> getMessageHandlerProperties() {
        return messageHandlerPropertiesObj;
    public void setMessageHandlerProperties(List<Map<String,String>> messageHandlerPropertiesObj) {
        if (messageHandlerPropertiesObj == null) {
            System.out.println("[MessageHandlerChain] setMessageHandlerProperties() can't be given a null value.");
            return;
        this.messageHandlerPropertiesObj = messageHandlerPropertiesObj;
    @PrePersist
     * This method is invoked by the persistence provider prior to every persist operation.
     * This is needed because we need to convert, serialize, our <code>@Transient</code> annotated objects into <code>byte[]</code> streams
     * so that they can be written into the database.
    public void prePersist() {
        System.out.println("[MessageHandlerChain] prePersist()");
        if (messageHandlerPropertiesObj != null)
            messageHandlerProperties = BlobConverter.objectToBytes(messageHandlerPropertiesObj);
        if (messageHandlersObj != null)
            messageHandlers = BlobConverter.objectToBytes(messageHandlersObj);
    @PostLoad
     * This method is invoked by the persistence provider after every load operation.
     * This is needed because we need to convert, deserialize, <code>byte[]</code> streams back to our <code>@Transient</code> annotated objects.
    public void postLoad() {
        System.out.println("[MessageHandlerChain] postLoad()");
        try {
            if (messageHandlerProperties != null)
                messageHandlerPropertiesObj = (List<Map<String,String>>)BlobConverter.bytesToObject(messageHandlerProperties);
            if (messageHandlers != null)
                messageHandlersObj = (List<String>)BlobConverter.bytesToObject(messageHandlers);
        } catch (ClassCastException e) {
            System.out.println("[MessageHandlerChain] postLoad() Class Cast Exception: "+e);
    public String toString() {
        return "[MessageHandlerChain] messageHandlerChainID="+getMessageHandlerChainID()+", messageHandlers="+getMessageHandlers()+", messageHandlerProperties="+getMessageHandlerProperties();
The helper class
* <code>BlobConverter</code> is a simple helper class to encode and decode classes as byte[] so that they can be stored into persistent storage.
* @author Samuli Piela
public class BlobConverter {
    public static byte[] objectToBytes(Object o) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream(512);
        ObjectOutputStream oos = null;
        try {
            oos = new ObjectOutputStream(baos);
            oos.writeObject(o);
            return baos.toByteArray();
        } catch (InvalidClassException e) {
            System.out.println("objectToBytes("+o+"): Invalid Class: "+e);
        } catch (NotSerializableException e) {
            System.out.println("objectToByte("+o+"): Object not serializable: "+e);
        } catch (Exception e) {
            System.out.println("objectToBytes("+o+"): Exception: "+e);
        } finally {
            if (oos != null) {
                try {
                    oos.close();
                } catch (IOException e) {
                    System.out.println("objectToBytes(): Stream could not be closed: "+e);
            if (baos != null) {
                try {
                    baos.close();
                } catch (IOException e) {
                    System.out.println("objectToBytes(): Stream could not be closed: "+e);
            oos = null;
            baos = null;
        return null;
    public static Object bytesToObject(byte[] byteArray) {
        ByteArrayInputStream bais = new ByteArrayInputStream(byteArray);
        ObjectInputStream ois = null;
        try {
            ois = new ObjectInputStream(bais);
            Object o = ois.readObject();
            return o;
        } catch (ClassNotFoundException e) {
            System.out.println("bytesToObject(): Class not found: "+e);
        } catch (InvalidClassException e) {
            System.out.println("bytesToObject(): Invalid Class: "+e);
        } catch (IOException e) {
            System.out.println("bytesToObject(): IOException: "+e);
        } catch (Exception e) {
            System.out.println("bytesToObject(): Exception: "+e);
        } finally {
            if (ois != null) {
                try {
                    ois.close();
                } catch (IOException e) {
                    System.out.println("bytesToObject(): Stream could not be closed: "+e);
            if (bais != null) {
                try {
                    bais.close();
                } catch (IOException e) {
                    System.out.println("bytesToObject(): Stream could not be closed: "+e);
            ois = null;
            bais = null;
        return null;
}

anyone?

Regarding CMP entity bean

in ejb-jar.xml when i add select method "CMP select methods" it get added into CMP entity bean.
I have added lookup method than got the refrence of LocalHomeInterface in the servlet
Now my confusion is how to use this method to get the returbed value from that added select method.
Please guide me.
regards
gaurav

Hi Young,
From the information you have supplied, my guess is that the SQL
string that OC4J is sending to SQL-Server is incorrect. So it may
help if you could see the exact SQL string. In order to see the
SQL string, I suggest you either run OC4J in "debug" mode, or try
using "P6 Spy".
The following web page has details on running OC4J in "debug" mode:
http://kb.atlassian.com/content/atlassian/howto/orionproperties.jsp
And here is the web page for "P6 Spy"
http://www.provision6.com/
And these other web sites may also be of help (in general):
http://www.orionserver.com
http://www.orionsupport.com
http://www.atlassian.com
http://www.elephantwalker.com
Good Luck,
Avi.

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

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

Noob Question: Problem with Persistence in First Entity Bean

Hey folks,
I have started with EJB3 just recently. After reading several books on the topic I finally started programming myself. I wanted to develop a little application for getting a feeling of the technology. So what I did is to create a AppClient, which calls a Stateless Session Bean. This Stateless Bean then adds an Entity to the Database. For doing this I use Netbeans 6.5 and the integrated glassfish. The problem I am facing is, that the mapping somehow doesnt work, but I have no clue why it doesn't work. I just get an EJBException.
I would be very thankfull if you guys could help me out of this. And don't forget this is my first ejb project - i might need a very detailed answer ... I know - noobs can be a real ....
So here is the code of the application. I have a few methods to do some extra work there, you can ignore them, there are of no use at the moment. All that is really implemented is testConnection() and testAddCompany(). The testconnection() Methode works pretty fine, but when it comes to the testAddCompany I get into problems.
Edit:As I found out just now, there is the possibility of Netbeans to add a Facade pattern to an Entity bean. If I use this, everythings fine and it works out to be perfect, however I am still curious, why the approach without the given classes by netbeans it doesn't work.
public class Main {
    private EntryRemote entryPoint = null;
    public static void main(String[] args) throws NamingException {
        Main main = new Main();
        main.runApplication();
    private void runApplication()throws NamingException{
        this.getContext();
        this.testConnection();
        this.testAddCompany();
        this.testAddShipmentAddress(1);
        this.testAddBillingAddress(1);
        this.testAddEmployee(1);
        this.addBankAccount(1);
    private void getContext() throws NamingException{
        InitialContext ctx = new InitialContext();
        this.entryPoint = (EntryRemote) ctx.lookup("Entry#ejb.EntryRemote");
    private void testConnection()
        System.err.println("Can Bean Entry be reached: " + entryPoint.isAlive());
    private void testAddCompany(){
        Company company = new Company();
        company.setName("JavaFreaks");
        entryPoint.addCompany(company);
        System.err.println("JavaFreaks has been placed in the db");
    }Here is the Stateless Session Bean. I added the PersistenceContext, and its also mapped in the persistence.xml file, however here the trouble starts.
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Stateless(mappedName="Entry")
public class EntryBean implements EntryRemote {
    @PersistenceContext(unitName="PersistenceUnit") private EntityManager manager;
    public boolean isAlive() {
        return true;
    public boolean addCompany(Company company) {
        manager.persist(company);
        return true;
    public boolean addShipmentAddress(long companyId) {
        return false;
    public boolean addBillingAddress(long companyId) {
        return false;
    public boolean addEmployee(long companyId) {
        return false;
    public boolean addBankAccount(long companyId) {
        return false;
}That you guys and gals will have a complete overview of whats really going on, here is the Entity as well.
package ejb;
import java.io.Serializable;
import javax.persistence.*;
@Entity
@Table(name="COMPANY")
public class Company implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @Column(name="COMPANY_NAME")
    private String name;
    public Long getId() {
        return id;
    public void setId(Long id) {
        this.id = id;
   public String getName() {
        return name;
    public void setName(String name) {
        this.name = name;
        System.err.println("SUCCESS: CompanyName SET");
    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof Company)) {
            return false;
        Company other = (Company) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        return true;
    @Override
    public String toString() {
        return "ejb.Company[id=" + id + "]";
}And the persistence.xml file
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
<persistence-unit name="PersistenceUnit" transaction-type="JTA">
    <provider>oracle.toplink.essentials.PersistenceProvider</provider>
    <jta-data-source>jdbc/sample</jta-data-source>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties>
      <property name="toplink.ddl-generation" value="create-tables"/>
    </properties>
</persistence-unit>
</persistence>And this is the error message
08.06.2009 10:30:46 com.sun.enterprise.appclient.MainWithModuleSupport <init>
WARNUNG: ACC003: Ausnahmefehler bei Anwendung.
javax.ejb.EJBException: nested exception is: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
        java.rmi.RemoteException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaktion für Zurücksetzung markiert.; nested exception is:
        javax.transaction.RollbackException: Transaktion für Zurücksetzung markiert.
java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
        java.rmi.RemoteException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaktion für Zurücksetzung markiert.; nested exception is:
        javax.transaction.RollbackException: Transaktion für Zurücksetzung markiert.
        at com.sun.corba.ee.impl.javax.rmi.CORBA.Util.mapSystemException(Util.java:243)
        at com.sun.corba.ee.impl.presentation.rmi.StubInvocationHandlerImpl.privateInvoke(StubInvocationHandlerImpl.java:205)
        at com.sun.corba.ee.impl.presentation.rmi.StubInvocationHandlerImpl.invoke(StubInvocationHandlerImpl.java:152)
        at com.sun.corba.ee.impl.presentation.rmi.bcel.BCELStubBase.invoke(BCELStubBase.java:225)
        at ejb.__EntryRemote_Remote_DynamicStub.addCompany(ejb/__EntryRemote_Remote_DynamicStub.java)I spend half the night figuring out whats wrong, however I couldnt find any solution.
If you have any idea pls let me know
Best regards and happy coding
Taggert
Edited by: Taggert_77 on Jun 8, 2009 2:27 PM

Well I don't understand this. If Netbeans created a Stateless Session Bean as a facade then it works -and it is implemented as a CMP, not as a BMP as you suggested.
I defenitely will try you suggestion, just for curiosity and to learn the technology, however I dont have see why BMP will work and CMP won't.
I also don't see why a stateless bean can not be a CMP. As far as I read it should not matter. Also on the link you sent me, I can't see anything related to that.
Maybe you can help me answering these questions.
I hope the above lines don't sound harsh. I really appreciate your input.
Best regards
Taggert

Report with entity beans - BIG performance problem

I have several EJBs (CMP entity beans).
I need to build a report using linked EJBs and show this report
to a user (so, updates are not needed - report is only for web page demonstration).
the problem is: such report is generated too slow.
I have ~100 records in table 'TestResult' and ~500 records in table 'TestObject'.
these tables are linked like this:
one testobject <--> many testresults
for each testresult I need to show a line with some info which should be retrieved
from bound EJBs (e.g. testresult-testobject-assigneduser-prioritylevel)
how to optimize such report generation?
I have heard something about session beans with Value Objects.
do I need to use such session beans here?
what is a general solution for generating reports using linked EJBs?
I tried to solve the problem by using DB View, but it didn't help.
I have used 'TestResultView' - info is retrieved fast enough from this view
(several msecs), but displaying this info is still very costly.
please, help!
Oracle 8.1.7,
WebLogic 6.1

Hi,
because I have checked the time required to
1) retrieve EJBS (several msec)Let me share some of my views with you.Once you retrieve the EJBS ie ie the collection of remote interface from the finder method the container is firing single "select " query and gets all the primary keys back.
2) cycle through it - get fields and display them
(~4000 msec)Now the cycle of getting the value you are getting the bean from the PooledState to ready state which will get the fields by firing the "select" query (ejbload()). Now in the instance you are invoking the multiple methods and at the end it will remain there in ready till you call the remove which u are not doing so the time out will bring it back to the pooledstate.
And if you are calling the bean very frequently then all the instances will go to the ready state and the activation & passivation will start developing ......
So at the end when the bean moves back to the pooled state after timeout the ejbStore() fires the "update " query!!!!
Let us consider the activation/passivation not appearing for simple understanding !!!!!!!!
So for each iteration you are firing 2 queries to the database.So if you have 500 records then the queries generatted will be 1(select from finder)+2(1 by select(ejbload)+1 by update(ejbStore))*500. So the flow is calling 1001 queries ...Thus quering about 1000 queries will definetly take some time...
So what is the solution????
Any way you dont require to fire the update query as you are just viewing the data...So u can stop calling the ejbStore().
Hence you queries will drop to half.Now how we can do this is by using the BMP.....
The other solution is using the Sessionbean and store the data all 500 records in the Object which can be called across the n/w. This object should implements the Serializable interface and this tech is the Transfer Object feature.....
Hope you find this useful..
regards
Vicky

Problem with 1-to-many relationship between entity beans

Hi All!
I have two tables TMP_GROUP and TMP_EMPLOYEE with following fields:
TMP_GROUP: ID, CAPTION, COMMENT, STATUS.
TMP_EMPLOYEE: ID, LOGIN, GROUP_ID.
For this tables i create two entity beans GROUP and EMPLOYEE respectively.
The relationship looks like this
descriptor ejb.xml:
<ejb-relation>
            <description>description</description>
            <ejb-relation-name>employeesOfGroup</ejb-relation-name>
            <ejb-relationship-role>
                <ejb-relationship-role-name>com.mypackage.GroupBean</ejb-relationship-role-name>
                <multiplicity>One</multiplicity>
                <relationship-role-source>
                    <ejb-name>GroupBean</ejb-name>
                </relationship-role-source>
                <cmr-field>
                    <cmr-field-name>employees</cmr-field-name>
                    <cmr-field-type>java.util.Collection</cmr-field-type>
                </cmr-field>
            </ejb-relationship-role>
            <ejb-relationship-role>
                <ejb-relationship-role-name>com.mypackage.EmployeeBean</ejb-relationship-role-name>
                <multiplicity>Many</multiplicity>
                <relationship-role-source>
                    <ejb-name>EmployeeBean</ejb-name>
                </relationship-role-source>
            </ejb-relationship-role>
        </ejb-relation>
descriptor persistent.xml:
<table-relation>
               <table-relationship-role
                    key-type="PrimaryKey">
                    <ejb-name>GroupBean</ejb-name>
                    <cmr-field>employees</cmr-field>
               </table-relationship-role>
               <table-relationship-role
                    key-type="NoKey">
                    <ejb-name>EmployeeBean</ejb-name>
                    <fk-column>
                         <column-name>GROUP_ID</column-name>
                         <pk-field-name>ejb_pk</pk-field-name>
                    </fk-column>
               </table-relationship-role>
          </table-relation>
Now i implement business method:
public Long addEmployee(String login, long groupId) {
          Long result;
          try {
               EmployeeLocal employee = employeeHome.create(login);
               GroupLocal group =
                    groupHome.findByPrimaryKey(new Long(groupId));
               Collection employees = group.getEmployees();
               employees.add(employee);
               result = (Long) employee.getPrimaryKey();
          } catch (CreateException ex) {
               result = new Long(0);
          } catch (FinderException ex) {
               result = new Long(0);
          return result;
When i call this method from web service, the following exception is raised:
com.sap.engine.services.ejb.exceptions.BaseTransactionRolledbackLocalException: Exception in method com.mypackage.GroupLocalHomeImpl0.findByPrimaryKey(java.lang.Object).
P.S.
1) I have transaction attribute set to "Required" for all methods of all beans
2) I have unique index for each table:
TMP_GROUP_I1: CAPTION
TMP_EMPLOYEE_I1: LOGIN (however i think GROUP_ID must be added here too)
3) I tried many:many relationship with this tables and it works fine
4) I try another implementation of addEmployee method with
EmployeeLocal employee = employeeHome.create(login, groupId);
without using GroupLocal cmr-field and GroupLocalHome findByPrimaryKey method, the result is same error.
Can somebody help me with this problem?
Thanks in advance.
Best regards, Abramov Andrey.

gimbal2 wrote:
1: The @JoinColumn on the listOfDepartments collection in Company is wrong. It should be something like this for a bidirectional relationship:
@OneToMany(mappedBy="company") // company is the matching property name in Department
private List <Department> listOfDepartment = new ArrayList<Department>();Note that I removed the fetch configuration; onetomany is fetched lazy by design. Saves some clutter eh.
2: use a Set in stead of a List (hibernate doesn't like lists much in entities and will break when you create slightly more complex entity relations)
3: don't just slap cascades on collections, especially of type ALL. Do it with care. In the many years I've been using JPA I've only had to cascade deletes in very specific situations, maybe once or twice. I never needed any of the other cascade types, they just invite sloppy code if you ask me. When working with persistence you should apply a little precision.I made all changes as you mentioned but still compID in department table shows null value...

Problem with 1:many relationship between entity beans.

Hi All!
I have two tables TMP_GROUP and TMP_EMPLOYEE with following fields:
TMP_GROUP: ID, CAPTION, COMMENT, STATUS.
TMP_EMPLOYEE: ID, LOGIN, GROUP_ID.
For this tables i create two entity beans GROUP and EMPLOYEE respectively.
The relationship looks like this
descriptor ejb.xml:
<ejb-relation>
            <description>description</description>
            <ejb-relation-name>employeesOfGroup</ejb-relation-name>
            <ejb-relationship-role>
                <ejb-relationship-role-name>com.mypackage.GroupBean</ejb-relationship-role-name>
                <multiplicity>One</multiplicity>
                <relationship-role-source>
                    <ejb-name>GroupBean</ejb-name>
                </relationship-role-source>
                <cmr-field>
                    <cmr-field-name>employees</cmr-field-name>
                    <cmr-field-type>java.util.Collection</cmr-field-type>
                </cmr-field>
            </ejb-relationship-role>
            <ejb-relationship-role>
                <ejb-relationship-role-name>com.mypackage.EmployeeBean</ejb-relationship-role-name>
                <multiplicity>Many</multiplicity>
                <relationship-role-source>
                    <ejb-name>EmployeeBean</ejb-name>
                </relationship-role-source>
            </ejb-relationship-role>
        </ejb-relation>
descriptor persistent.xml:
<table-relation>
               <table-relationship-role
                    key-type="PrimaryKey">
                    <ejb-name>GroupBean</ejb-name>
                    <cmr-field>employees</cmr-field>
               </table-relationship-role>
               <table-relationship-role
                    key-type="NoKey">
                    <ejb-name>EmployeeBean</ejb-name>
                    <fk-column>
                         <column-name>GROUP_ID</column-name>
                         <pk-field-name>ejb_pk</pk-field-name>
                    </fk-column>
               </table-relationship-role>
          </table-relation>
Now i implement business method:
public Long addEmployee(String login, long groupId) {
          Long result;
          try {
               EmployeeLocal employee = employeeHome.create(login);
               GroupLocal group =
                    groupHome.findByPrimaryKey(new Long(groupId));
               Collection employees = group.getEmployees();
               employees.add(employee);
               result = (Long) employee.getPrimaryKey();
          } catch (CreateException ex) {
               result = new Long(0);
          } catch (FinderException ex) {
               result = new Long(0);
          return result;
When i call this method from web service, the following exception is raised:
com.sap.engine.services.ejb.exceptions.BaseTransactionRolledbackLocalException: Exception in method com.mypackage.GroupLocalHomeImpl0.findByPrimaryKey(java.lang.Object).
P.S.
1) I have transaction attribute set to "Required" for all methods of all beans
2) I have unique index for each table:
TMP_GROUP_I1: CAPTION
TMP_EMPLOYEE_I1: LOGIN (however i think GROUP_ID must be added here too)
3) I tried many:many relationship with this tables and it works fine
4) I try another implementation of addEmployee method with
EmployeeLocal employee = employeeHome.create(login, groupId);
without using GroupLocal cmr-field and GroupLocalHome findByPrimaryKey method, the result is same error.
Can somebody help me with this problem?
Thanks in advance.
Best regards, Abramov Andrey.

I have posted excerpts from my orion-ejb-jar.xml file in this posting: Problem mapping a 1:M relationship between two entity EJBs w/ a compound PK
Sorry for the duplicate postings, but I was getting errors on the submission.
April

Is it possible to map the cmp fields of the entity bean with out dictionary

Dear sirs,
I have created the EJB project module and WEB Module. Now i have to map the CMP fields of the entity bean to the underlying table. Is it possible to map the cmp fields of the entity bean with out java dictionary? If yes how can we do that.
I have got some error while mapping an EJB's CMP fields to the table through dictionary. I was actually intended to map 79 fields but it gives an error that more than 64 fields are not allowed while building the dictionary.
1. Can you tell me what could be the possible reason?
2. Is it possible to map the cmp fields of the entity bean with out java dictionary? If yes how can we do that.
Kindly helo me,
Sudheesh K S

Hi,
Sudheesh please check up if the below link helps,there are other ways of writing the persistent.xml for container managed entity bean.
http://help.sap.com/saphelp_nw04s/helpdata/en/9b/f695f0c84acf46a4e0b31f69d8a9b7/frameset.htm, probably in the studio you cannot browse through tables not in the java dictionary,but manually editing it may still solve the problem.
Also here is another link that specifies the databases supported by J2EE Engine.
http://help.sap.com/saphelp_nw04s/helpdata/en/66/a5283eeb47b40be10000000a114084/frameset.htm
The below link shows how to specify the database vendor and datasource
http://help.sap.com/saphelp_nw04s/helpdata/en/e1/67fc3ee241ba28e10000000a114084/frameset.htm
Hope you are able to solve the problem.
Do let us know if you come up with the solution.
Regards,
Harish
Message was edited by: HARISH SUBRAMANIAN

EJB 3.0 entity beans and WebDynpro models

Hi all,
first off all my setup:
WebDynpro Development Component: dcA
EJB Module Development Component: dcB
i wan't to create Entity Beans in dcB an use it for my model in dcA.
My questions:
1. Why does the "New Wizard" only offer EJB 3.0 Session and Message Beans an no Entity Beans? What is the correct way for creating Entity Beans in DevStudio?
2. Is ist right that i have to define a public Part containing the Entity Bean to make it visible to dcA?
Regards,
Christian

Hi,
I'm experiencing same problems, is this a bug or an feature?

Error while deploying Entity Beans on OC4J 10.1.3

Hi,
We have 350 entity beans in our system. Recently a new table is created as per following script.
CREATE TABLE TBLSMDTATTRIBUTECATREL
MDTCATEGORYID CHAR(7),
ATTRIBUTECATEGORYID CHAR(10),
CONSTRAINT PK_MDTATTRIBUTECATREL PRIMARY KEY (MDTCATEGORYID,ATTRIBUTECATEGORYID)
Entity Bean for the same has been created. While deploying I am facing the following error.
06/06/11 13:09:23 Notification ==> Error while compiling EJB component: file:/export/home/oc4j/j2ee/home/applications/JispAppEntities/billing-entities.jar
com.evermind.compiler.CompilationException: Method public abstract java.lang.String com.elitecore.billing.ejb.system.entity.MdtattributecatrelCMP.getMdtcategoryid() can not be declared abstract for entity 'Mdtattributecatrel'
at com.evermind.server.ejb.compilation.CMPObjectCompilation.verifyMethods(CMPObjectCompilation.java:800)
at com.evermind.server.ejb.compilation.CMPObjectCompilation.<init>(CMPObjectCompilation.java:55)
at com.evermind.server.ejb.compilation.PersistenceManagerCompilation.<init>(PersistenceManagerCompilation.java:26)
at com.evermind.server.ejb.compilation.EntityBeanCompilation.<init>(EntityBeanCompilation.java:121)
at com.evermind.server.ejb.compilation.Compilation.generateAnyOldStyle(Compilation.java:1593)
at com.evermind.server.ejb.compilation.Compilation.compile(Compilation.java:181)
at com.evermind.server.ejb.compilation.Compilation.doGenerateCode(Compilation.java:249)
at com.evermind.server.ejb.EJBContainer.postInit(EJBContainer.java:971)
at com.evermind.server.ApplicationStateRunning.initializeApplication(ApplicationStateRunning.java:205)
at com.evermind.server.Application.setConfig(Application.java:387)
at com.evermind.server.Application.setConfig(Application.java:304)
at com.evermind.server.ApplicationServer.addApplication(ApplicationServer.java:1651)
at oracle.oc4j.admin.internal.ApplicationDeployer.addApplication(ApplicationDeployer.java:402)
at oracle.oc4j.admin.internal.ApplicationDeployer.doDeploy(ApplicationDeployer.java:158)
at oracle.oc4j.admin.internal.DeployerBase.execute(DeployerBase.java:93)
at com.evermind.server.administration.DefaultApplicationServerAdministrator.internalDeploy(DefaultApplicationServerAdministrator.java:440)
at com.evermind.server.administration.DefaultApplicationServerAdministrator.deploy(DefaultApplicationServerAdministrator.java:341)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at com.evermind.server.rmi.ServerRmiMessageHandler.doMethodCall(ServerRmiMessageHandler.java:560)
at com.evermind.server.rmi.ServerRmiMessageHandler.handleMethodInvocation(ServerRmiMessageHandler.java:471)
at com.evermind.server.rmi.ServerRmiMessageHandler.handleOrmiRequest(ServerRmiMessageHandler.java:262)
at com.evermind.server.rmi.ServerRmiMessageHandler.dispatchRequest(ServerRmiMessageHandler.java:231)
at com.evermind.server.rmi.RMIServerConnection.processReceivedCommand(RMIServerConnection.java:155)
at com.evermind.server.rmi.RMIConnection.handleCommand(RMIConnection.java:151)
at com.evermind.server.rmi.RMIConnection.listenForOrmiCommands(RMIConnection.java:126)
at com.evermind.server.rmi.RMIConnection.run(RMIConnection.java:105)
at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:298)
at java.lang.Thread.run(Thread.java:534)
Can anybody please suggest the solution?
Thanks in advance.
Regards,
Jinal Shah

Hi,
The error was coming because of the table structure. All the columns were composite keys. I alter the structured by removing composite keys and added a new column as primary key. Now it is getting deployed successfully.
Can anybody comment on such a behaviour of OC4J?
Regards,
Jinal Shah

Composite Primary Key in M:N CMP Entity Bean Relationship

Dear Sir/Madam,
     We are creating an Enterprise Application for our institute using EJB 2.0 specifiactions. In the course of developement, we are facing a problem in writing the CMP Entity Beans with EJB Relationships.
     We are having many to many relationship between two beans such that the primary key of one Entity Bean (let's call it A), serves as the foreign key of another Entity Bean (let's call it B). Further, this primary key of A as foreign key in B, participates in the composite key of B.
     The EJB Specifications require that the primary key field(s) of any bean (B, in our case) declared in the Primary Key class should be the subset of the 'cmp-field' declared in the deployment descriptor for that bean. As I said earlier, we have many to many relationship at play. Hence, we require to keep the foerign key in the 'cmr-field' in lieu of 'cmp-field'. In short, the component of primary key is in 'cmr-field' while, it is needed in both 'cmp-field' and 'cmr-field'. That's perfect from Database point of view but illogical from CMP Entity Bean's view.
     How can we write the deployment descriptor for such a CMP (BMP is working fine for above scenario) Entity Bean? Also, how can we write the Primary Key class? The problem is not just to find the solution, but find under the hood of EJB 2.0 specifications.
     Please help.

I think you should realise that it would not be convenient to use CMP for everything. It is difficult to define complex relations using CMP. Mostly BMP os preferd since it gives the flexibility for the bean developer.
Regards
xH4x0r

Exception in calling a CMP Entity Bean

I have deployed a simple CMP entity bean using jboss App. server, Now while executing the client i got the following exception,
error in clientjavax.naming.CommunicationException [Root exception is java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:
java.lang.ClassNotFoundException: org.jnp.interfaces.FastNamingProperties (no security manager: RMI class loader disabled)]
regards,
NaveenBabu.A

Hi,
It is likely that some libraries are missing in your client environment. (it has nothing to do with security)
Make sure that the libraries in JBoss client (folder your_jboss_folder/client) are in your client application classpath. In particular, look for jnp-client.jar.
This should solve the problem.
Bruno Collet
http://www.practicalsoftwarearchitect.com

Regarding Entity bean

Similar Messages

Maybe you are looking for