Using oracle db sequence for auto generating of PKs for CMP entity beans

Question

Hi,
I have read quite a number of threads about (auto) generation of keys for primary keys for the CMP entity beans.
My requirement is I am migrating an application deployed on Weblogic to oc4j. The application is using cmp entity beans with auto key generation using a sequence in the Oracle db. This is specified in weblogic-cmp-rdbms-jar.xml file like below:
<automatic-key-generation>
<generator-type>Oracle</generator-type>
<generator-name>REPUSER.DEPT_REPORT_SEQ</generator-name>
<key-cache-size>1</key-cache-size>
</automatic-key-generation>
In the ejb-jar.xml, it is specified as:
<prim-key-class>java.lang.Integer</prim-key-class>
<primkey-field>id</primkey-field>
Now, I need to migrate this to oc4j. Can somebody suggest me options and clarify my questions kindly?
1) I have read articles that say that in the ejb-jar.xml, we need to specify <prim-key-class>java.lang.Object</prim-key-class> and this will create a column called 'autoid' in the respective entity table in the Oracle db.
- How can I use this to assign the value to my primary field, say, id?
2) Now, with the latest oc4j, can I use Oracle database sequence as the key generator for the values of the PKs just by specifying in the xml descriptor ejb-jar.xml?
2.a) If yes, is there any article that explains with the code?
2.b) If no, what are the alternatives I have?
I have read many discussions that say that we can create a stateless session bean that can lookup the database sequence using simple JDBC call to return the nextval of the sequence. The SSB should be called in the ejbCreate() of the entity bean.
My related question is, what is recommended for oc4j? What are limitations of the various options for the latest oc4j available?
How should I go about deploying this kind of ejbs in oc4j?
Any help and pointers are welcome. Please help.
Thanks a lot.
Vadi

Answer 1

Hello ,
Instead of exposing a get/set method for each arribute of your bean (corresponding to database table) expose only one object.
For example
public class CustomerBean implements javax.ejb.EntityBean{
private CustomerVO objCustomer;
private String customerName;
private String customerMail;
private String customerType;
public CustomerVO getCustomer(){
return this.objCustomer;
public void setCustomer(CustomerVO objCustomer){
this.objCustomer = objCustomer;
public void ejbStore(){
customerName = objCustomer.getName();
customerMail = objCustomer.getMail();
customerType = objCustomer.getType();
HTH
VJ