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

Similar Messages

Relationships in CMP Entity Beans

Hi everyone;
There is a way to implement one-to-many and many-to many relationships in CMP Entity Beans, is there a way to specify a parametrized query or something that do the job on the DBMS?
Regards Francisco.

Container's cascade-deleting in jboss(tm)3.2.x working properly with any scope:
This example with 1 scope:
    <relationships>
        <ejb-relation>
            <ejb-relation-name>Region-Town</ejb-relation-name>
            <ejb-relationship-role>
                <ejb-relationship-role-name>region-has-towns</ejb-relationship-role-name>
                <multiplicity>One</multiplicity>
                <relationship-role-source>
                    <ejb-name>RegionBean</ejb-name>
                </relationship-role-source>
                <cmr-field>
                    <cmr-field-name>regionTowns</cmr-field-name>
                    <cmr-field-type>java.util.Set</cmr-field-type>
                </cmr-field>
            </ejb-relationship-role>
            <ejb-relationship-role>
                <ejb-relationship-role-name>town-belongs-to-region</ejb-relationship-role-name>
                <multiplicity>Many</multiplicity> <cascade-delete/>
                <relationship-role-source>
                    <ejb-name>TownBean</ejb-name>
                </relationship-role-source>
                <cmr-field>
                    <cmr-field-name>region</cmr-field-name>
                </cmr-field>
            </ejb-relationship-role>
        </ejb-relation>
    </relationships>

Help about Date and Time by CMP entity bean

I should have two fields in my cmp .one stores current date ,another one stores current time while ejbcreate();
I should be able to get findmethod findobjectBetween ?! and ?2
or that sorts of find method.what type of the method should I use.
java.util.Date or Simply String?
if I use java.tuil.Date as the type.
How shoud my ejbcreate method look like?
public abstract void setDate(Date mydate);
public abstract Date getDate();
ejbCreate(String name,String password,Date mydate,Date mytime)
setDate()
I suppose I use write a business method getCurrentDate() which uses
java.util.Date().toLocale,But I think it just returns String
help pls.

I am using oc4j(Oracle9iAS (9.0.3.0.0))
I am getting the following error using Timestamp while deploying cmp entity bean ejb1.1. Thanks...
Auto-deploying TimestampTestEntity.jar (No previous deployment found)... TimestampTest_EntityBeanWrapper0.java:1558: Missing term.
if (if(thread.contextContainer != null)
^
TimestampTest_EntityBeanWrapper0.java:1558: ')' expected.
if (if(thread.contextContainer != null)
^
TimestampTest_EntityBeanWrapper0.java:1559: Invalid expression statement.
response != null) {if(thread.contextContainer != null)
         ^
TimestampTest_EntityBeanWrapper0.java:1559: ';' expected.
response != null) {if(thread.contextContainer != null)
                ^
TimestampTest_EntityBeanWrapper0.java:1560: Missing term.
response.setNanos(if(thread.contextContainer != null)
                  ^
TimestampTest_EntityBeanWrapper0.java:1560: ')' expected.
response.setNanos(if(thread.contextContainer != null)
                  ^
TimestampTest_EntityBeanWrapper0.java:1561: ';' expected.
response.getNanos());} // generated from BeanMethodCompilation
^
7 errors
Error compiling F:\oc4j\j2ee\home\applications\TimestampAppl/TimestampTestEntity.jar: Syntax error in source
Oracle9iAS (9.0.3.0.0) Containers for J2EE initialized

How to manage a XMLType in a CMP Entity Bean

Hi everyone.
Have any of you dealt with a XMLType in a CMP Entity Bean, for instance, the oracle CLOB datatype or directly with XMLType? any of you have tried with a successful result?
What I have to do for creating a CMP if the destination table is going to have a XMLType column. Because I need to Store a very large XML Document.
I will really appreciate.
Thank you
Francisco.

Francisco,
In case you haven't already seen it, perhaps this blog from Debu Panda will help:
http://radio.weblogs.com/0135826/2004/08/11.html#a60
Good Luck,
Avi.

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

Problem in creating CMP Entity Bean - Pls Help

I am trying to build one simple project having jsps to get connected to CMP Entity Bean.
But while deploying I am getting the following error...
Nov 15, 2004 10:59:09... Info: End of log messages of the target system.
Nov 15, 2004 10:59:09... Info: ***** End of SAP J2EE Engine Deployment (J2EE Application) *****
Nov 15, 2004 10:59:09... Error: Execution of deployment action for "EntityCMPAppln" aborted:
Caught exception during application deployment from SAP J2EE Engine's deploy service:
java.rmi.RemoteException: Error occurred while starting application bcone.com/EntityCMPAppln and wait.
Reason: Complex error : server ID 6155350:Application bcone.com/EntityCMPAppln cannot be started, because it has hard reference to resource CONFIG_DB with type javax.sql.DataSource, but it is not active on the server.
(message ID: com.sap.sdm.serverext.servertype.inqmy.extern.EngineApplOnlineDeployerImpl.performAction(DeploymentActionTypes).REMEXC)
Nov 15, 2004 10:59:09... Error: Deployment NOT successful for EntityCMPAppln
Nov 15, 2004 10:59:09... Info: SDM configuration: Do not automatically start/stop J2EE Engine. Do not restore state of J2EE Engine now.
Nov 15, 2004 10:59:09... Error: -
At least one of the Deployments failed -
Nov 15, 2004 11:05:16... Info: Request for Logon as admin accepted
===========================================
Nov 15, 2004 11:05:08... Info: =   Starting to execute command 'remotegui'   =
Nov 15, 2004 11:05:08... Info: ===============================================
Nov 15, 2004 11:05:10... Info: SDM started successfully.
Please tell me how to activate the CONFIG_DB reference in database. Or what Extra I have to do to run this example.
Regards,
Vivek Ojha

Dear Benny,
The code of the required files is pasted below....
Application.XML
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE application PUBLIC "-//Sun Microsystems, Inc.//DTD J2EE Application 1.3//EN"
                             "http://java.sun.com/dtd/application_1_3.dtd">
<application>
    <display-name>EntityCMPAppln</display-name>
    <description>EAR description</description>
    <module>
        <ejb>EntityCMPEjb.jar</ejb>
    </module>
    <module>
        <web>
            <web-uri>EntityCMPWeb.war</web-uri>
            <context-root>/student</context-root>
        </web>
    </module>
</application>
Application-j2ee-engine.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE application-j2ee-engine SYSTEM "application-j2ee-engine.dtd">
<application-j2ee-engine>
     <provider-name>bcone.com</provider-name>
     <fail-over-enable
          mode="disable"/>
</application-j2ee-engine>
data-source-aliases.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE data-source-aliases SYSTEM "data-source-aliases.dtd">
<data-source-aliases>
     <aliases>
          <data-source-name>${com.sap.datasource.default}</data-source-name>
          <alias>STUDENTDB</alias>
     </aliases>
</data-source-aliases>
ejb-j2ee-engine.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-j2ee-engine SYSTEM "ejb-j2ee-engine.dtd">
<ejb-j2ee-engine>
     <enterprise-beans>
          <enterprise-bean>
               <ejb-name>StudentBean</ejb-name>
               <resource-ref>
                    <res-ref-name>jdbc/STUDENTDB</res-ref-name>
                    <res-link>STUDENTDB</res-link>
               </resource-ref>
               <entity-props/>
          </enterprise-bean>
     </enterprise-beans>
</ejb-j2ee-engine>
ejb-jar.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-jar PUBLIC "-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN" "http://java.sun.com/dtd/ejb-jar_2_0.dtd">
<ejb-jar>
     <description>EJB JAR description</description>
     <display-name>EJB JAR</display-name>
     <enterprise-beans>
          <entity>
               <ejb-name>StudentBean</ejb-name>
               <home>com.bcone.ejb.StudentHome</home>
               <remote>com.bcone.ejb.Student</remote>
               <ejb-class>com.bcone.ejb.StudentBean</ejb-class>
               <persistence-type>Container</persistence-type>
               <prim-key-class>java.lang.String</prim-key-class>
               <reentrant>False</reentrant>
               <cmp-version>2.x</cmp-version>
               <abstract-schema-name>StudentBean</abstract-schema-name>
               <cmp-field>
                    <field-name>studentId</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>lname</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>standard</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>fyear</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>fname</field-name>
               </cmp-field>
               <primkey-field>studentId</primkey-field>
               <resource-ref>
                    <res-ref-name>jdbc/STUDENTDB</res-ref-name>
                    <res-type>javax.sql.DataSource</res-type>
                    <res-auth>Container</res-auth>
               </resource-ref>
          </entity>
     </enterprise-beans>
</ejb-jar>
persistent.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE persistent-ejb-map SYSTEM "persistent.dtd">
<persistent-ejb-map>
     <locking
          type="Table"/>
     <db-properties>
          <data-source-name>CONFIG_DB</data-source-name>
          <database-vendor
               name="SAPDB"/>
     </db-properties>
     <entity-beans>
          <entity-bean>
               <ejb-name>StudentBean</ejb-name>
               <table-name>TMP_STUDENTNEW</table-name>
               <field-map
                    key-type="PrimaryKey">
                    <field-name>studentId</field-name>
                    <column>
                         <column-name>STUDENTID</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>lname</field-name>
                    <column>
                         <column-name>LNAME</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>standard</field-name>
                    <column>
                         <column-name>STANDARD</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>fyear</field-name>
                    <column>
                         <column-name>FYEAR</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>fname</field-name>
                    <column>
                         <column-name>FNAME</column-name>
                    </column>
               </field-map>
          </entity-bean>
     </entity-beans>
     <relationships/>
</persistent-ejb-map>
StudentBean.java
package com.bcone.ejb;
import javax.ejb.EntityBean;
import javax.ejb.EntityContext;
import javax.ejb.RemoveException;
import javax.ejb.CreateException;
@abstractSchemaName StudentBean
@cmpVersion 2.x
@ejbHome <{com.bcone.ejb.StudentHome}>
@ejbPrimaryKey <{java.lang.String}>
@ejbRemote <{com.bcone.ejb.Student}>
@hasSimplePK true
public abstract class StudentBean implements EntityBean {
     public void ejbLoad() {
     public void ejbStore() {
     public void ejbRemove() throws RemoveException {
     public void ejbActivate() {
     public void ejbPassivate() {
     public void setEntityContext(EntityContext context) {
          myContext = context;
     public void unsetEntityContext() {
          myContext = null;
     private EntityContext myContext;
@primKeyField
     public abstract String getStudentId();
     public abstract void setStudentId(String studentId);
     public abstract String getLname();
     public abstract void setLname(String lname);
     public abstract String getFname();
     public abstract void setFname(String fname);
     public abstract String getStandard();
     public abstract void setStandard(String standard);
     public abstract String getFyear();
     public abstract void setFyear(String fyear);
Create Method.
     public String ejbCreate(
          String studentId,
          String fname,
          String lname,
          String standard,
          String fyear)
          throws CreateException {
          setStudentId(studentId);
          setFname(fname);
          setLname(lname);
          setStandard(standard);
          setFyear(fyear);
          return null;
Post Create Method.
     public void ejbPostCreate(
          String studentId,
          String fname,
          String lname,
          String standard,
          String fyear) {
          // TODO : Implement
StudentData.java
Created on Nov 14, 2004
To change the template for this generated file go to
Window>Preferences>Java>Code Generation>Code and Comments
package com.bcone.data;
@author Administrator
To change the template for this generated type comment go to
Window>Preferences>Java>Code Generation>Code and Comments
public class StudentData {
     private String studentId;
     private String fname;
     private String lname;
     private String standard;
     private String fyear;
@return
     public String getFname() {
          return fname;
@return
     public String getFyear() {
          return fyear;
@return
     public String getLname() {
          return lname;
@return
     public String getStandard() {
          return standard;
@return
     public String getStudentId() {
          return studentId;
@param string
     public void setFname(String string) {
          fname = string;
@param string
     public void setFyear(String string) {
          fyear = string;
@param string
     public void setLname(String string) {
          lname = string;
@param string
     public void setStandard(String string) {
          standard = string;
@param string
     public void setStudentId(String string) {
          studentId = string;
student.jsp
<%@ page language="java" %>
<html>
     <head>
          <title>
               Title
          </title>
     </head>
     <body>
          <form method="POST" action="WEBBOT-SELF" name="Student" onSubmit="">

<br>
<a href="/student/manageStudent.jsp?action=add" method="post"> Create </a>
<a href="/student/manageStudent.jsp?action=modify" method="post"> Modify </a>
<a href="/student/manageStudent.jsp?action=delete" method="post"> Delete </a>
<br><br>
<table border="1" width="32%">
    <tr>
      <td width="39%">Student ID </td>
      <td width="61%"><input type="text" name="studentId" size="20"></td>
    </tr>
    <tr>
      <td width="39%">First Name</td>
      <td width="61%"><input type="text" name="fname" size="20"></td>
    </tr>
    <tr>
      <td width="39%">Last Name</td>
      <td width="61%"><input type="text" name="lname" size="20"></td>
    </tr>
    <tr>
      <td width="39%">Standard</td>
      <td width="61%"><input type="text" name="standard" size="20"></td>
    </tr>
    <tr>
      <td width="39%">Fiscal Year</td>
      <td width="61%"><input type="text" name="fyear" size="20"></td>
    </tr>
    <tr>
      <td width="39%" align="center"><input type="submit" value="Submit" name="submit"></td>
      <td width="61%" align="center"><input type="reset" value="Reset" name="reset"></td>
    </tr>
</table>
</form>
     </body>
</html>
mamageStudent.jsp
<%@ page language="java"
import="javax.naming.,java.sql.,javax.sql,com.bcone.ejb."
%>
<html>
     <head>
          <title>
               Manage Student
          </title>
     </head>
     <body>
          <h1>
          </h1>
<jsp:useBean id="stu" class="com.bcone.data.StudentData" ></jsp:useBean>
<jsp:setProperty name="stu" property="*" />
<%
try {
     InitialContext ctx = new InitialContext();
     StudentHome home = (StudentHome) ctx.lookup("java:comp/env/StudentBean");
     String str = request.getParameter("action");
     if("action".equals(str)) {
          Student rem = home.create(remote.setFname(stu.getStudentId(),stu.getFname(),stu.getLname(),stu.getStandard(),stu.getFyear());
          out.println(stu.getStudentId() + "Student Created");
     } else if ("modify".equals(str)) {
          Student remote = home.findByPrimaryKey(stu.getStudentId());
          remote.setFname(stu.getFname());
          remote.setFname(stu.getLname());
          remote.setFname(stu.getStandard());
          remote.setFname(stu.getFyear());
          out.println(stu.getStudentId() + "Student modified");
     } else if ("delete".equals(str)) {
          Student stu1 = home.findByPrimaryKey(stu.getStudentId());
          stu1.remove();
          out.println(stu.getStudentId() + "Student deleted");
} catch (Exception e) {
     out.println("Exception e"+e.toString());
%>
     </body>
</html>
Regards,
Vivek Ojha

How to use same transaction when calling CMP entity beans and DAO (JDBC)

We are currently using Weblogic 8.1 SP2 with an Oracle 10g database (using XA thin and non-XA drivers).
We have a session bean that invokes an entity bean and a DAO (data access object pattern) in order to add data in 2 separate tables (account and history). Rows are added to the first (account) table using a CMP Entity bean while inserts are done in the 2nd (history) table using a DAO. Here is some pseudo code:
addHistorySessionBean (trans-attribute="Required")
begin
Step #1 - call addAccountEntityBean (trans- attribute="Required")
Step #2 - call addHistoryDAO (get datasource, connection)
end
The 2nd table (history) has a foreign key constraint to ensure that the corresponding key exists in the first (account) table. Unfortunately, DAO inserts on the 2nd (history) table fail with a foreign key constraint violation (INTEGRITY CONSTRAINT VIOLATION - PARENT KEY NOT FOUND!) since they cannot see the row added to the 1st (account) table in step #1 by the CMP entity bean.
How does one ensure that all this is done in a single transaction ? It appears that the app server creates two seperate transactions (one for the session bean facade and the entity bean and a 2nd transaction (when we retrieve a connection using the same data source JNDI name) for the DAO.
A post on server side suggested using a "<resource-ref>" in the session bean to tie the two potentially separate transactions together, but that does not work for us. However, I am not sure if we are doing that correctly. After we define the resource ref in the session facade bean, do we use the resource ref "name" attribute to lookup the datasource or do we still lookup the datasource by JNDI name ? Do we need to define the resource-ref tag in the entity bean also ?
Does Weblogic allow using a single transaction for this type of a scenario ? How does one specify within Weblogic that the same transaction should be utilized by the entity bean and any subsequent DAOs?
People have also suggested that we defer constraint checking until the transaction(s) are committed but that sounds like a work acount without addressing this issue. Would postponing the constraint checking in Oracle cause any additional overhead ?
Any suggestions with specific examples or documentation on how to address this issue will be gratefully appreciated.

Thanks for your suggestion. Unfortunately, this does not work since it appears that there are 2 separate transactions going on here. One, the original one initiated by the session bean and used by the entity bean and the other initiated by the DAO. Any other ideas appreciated.
Hi,
Try setting the delay-database-inserts tag to
ejbCreate in RDBMS descriptor file.
http://bernal/stage/wls/docs81/ejb/DDreference-cmp-jar
.html#1113981
vasanthi ramesh

How to load the existing data from the databse in the CMP entity bean?

hello
my problem is as follows--
i am creating a CMP entity bean.in these beans client create the data instances using create() function.
now a entity bean will be created for the newly created data and it's EJBObject will also be formed.
now we will be able to perform finder methods over them.
remember these data has been newly created in the database.
but now if i want to perform the finder methods on the
existing data in the database( i don't need to use create() fn as i am not "creating" the data.). how will i perform the query over the existing data.
basically i have to make a CMP bean to extract the data corresponding to a particular condition , from the database table. i don't want to create the data in the database but just find out what data satisfies my condition.
thanking you
Prashant

you have to use findByXXX methods. depending on your appserver you may have to declare them (and eventually the query you want to be used) in the vendor specific deploiement descriptor.
(e.g. using jboss i don't remember having explicitly declare the findBySomeField method - where someField is a persistent field - in the dd, whereas with bas all finder methods have to be explicitly declared)
[note that obviously these methods have to be present in your home interface]

How to Create and Remove CMP Entity with Toplink in same transaction??

Hi, i have a problem to create and delete cmp intances with toplink.
I create a entity bean and remove the same entity bean in the same transaction.
ie. my method have this code:
bean a = homeBean.create(pk);
a.remove();
bean a = homeBean.create(pk);
this code throws a javax.ejb.DuplicateKeyException
Toplink not remove CMP, execute the two calls of create first.
What configure toplink to support this case ??
Is this possible ??
I Can't controling the transaction manualy i'm using CMP entity beans with CMT.
tanks.
Message was edited by:
Carlos Lacerda

BM,
If you want to import the utils package into your code, then the location of the utils package has to be in your CLASSPATH. JDeveloper uses libraries to define a project's CLASSPATH.
I'm not sure exactly what's going on here, but you might want to read the information about packages and class libraries in the online documentation. It's under:
User Guides
-> Working with JDeveloper
-> Packages and Class Libraries
Blaise

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.

ORA-01407 when removing a CMP Entity Bean with WLS 9.1

Hi all !
I hope you can help me to solve this ?:|
I'm migrating my application from WLS 8.1 SP3 to WLS 9.1.
I'm getting now an SQLException when I try to remove a CMP Entity Bean.
The stacktrace is as follows:
java.sql.SQLException: ORA-01407: cannot update ("USER"."MY_TABLE"."THE_CMR_FIELD") to NULL
     at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:145)
     at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:331)
     at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:288)
     at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:743)
     at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:216)
     at oracle.jdbc.driver.T4CPreparedStatement.executeForRows(T4CPreparedStatement.java:1120)
     at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1278)
     at oracle.jdbc.driver.OraclePreparedStatement.executeInternal(OraclePreparedStatement.java:3415)
     at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePreparedStatement.java:3498)
     at weblogic.jdbc.wrapper.PreparedStatement.executeUpdate(PreparedStatement.java:128)
Of course, I replaced the table and column names above to be more readable ;-)
The table MY_TABLE has a CMR field called THE_CMR_FIELD. The column is not nullable in the database (by the way, it's an Oracle 9i).
Everything is fine under WLS8.1
I tried two different Oracle JDBC drivers (9.2.0.5 and 10.2.0.1.0), but the result is always the same within WLS9.1.
Any ideas or suggestions (or even questions) are more than welcome!
Thanks
Eric

What's even more weird is that I have what seams to be the same problem on Weblogic 6.1 (SP4).
Here's the stacktrace:
<pre>
javax.ejb.EJBException:
Start server side stack trace:
java.sql.SQLException: ORA-01407: cannot update ("SCHEMA"."TIM_WP_DAY_CORE_PERIODS"."TWD_ID") to NULL
     at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
     at oracle.jdbc.ttc7.TTIoer.processError(TTIoer.java:289)
     at oracle.jdbc.ttc7.Oall7.receive(Oall7.java:573)
     at oracle.jdbc.ttc7.TTC7Protocol.doOall7(TTC7Protocol.java:1891)
     at oracle.jdbc.ttc7.TTC7Protocol.parseExecuteFetch(TTC7Protocol.java:1093)
     at oracle.jdbc.driver.OracleStatement.executeNonQuery(OracleStatement.java:2047)
     at oracle.jdbc.driver.OracleStatement.doExecuteOther(OracleStatement.java:1940)
     at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:2709)
     at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePreparedStatement.java:589)
     at com.p6spy.engine.logging.P6LogPreparedStatement.executeUpdate(P6LogPreparedStatement.java:183)
     at weblogic.jdbc.jts.Statement.executeUpdate(Statement.java:503)
     at package.WorkPatternDayCorePeriods_vd9y46__WebLogic_CMP_RDBMS.__WL_store(WorkPatternDayCorePeriods_vd9y46__WebLogic_CMP_RDBMS.java:2317)
     at weblogic.ejb20.manager.DBManager.flushModified(DBManager.java:438)
     at weblogic.ejb20.internal.TxManager$TxListener.flushModifiedKeys(TxManager.java:552)
     at weblogic.ejb20.internal.TxManager.flushModifiedBeans(TxManager.java:298)
     at weblogic.ejb20.manager.BaseEntityManager.flushModifiedBeans(BaseEntityManager.java:1246)
     at weblogic.ejb20.cmp.rdbms.RDBMSPersistenceManager.flushModifiedBeans(RDBMSPersistenceManager.java:1106)
     at weblogic.ejb20.manager.BaseEntityManager.cascadeDeleteRemove(BaseEntityManager.java:840)
     at weblogic.ejb20.manager.DBManager.remove(DBManager.java:656)
     at weblogic.ejb20.internal.EntityEJBLocalObject.remove(EntityEJBLocalObject.java:97)
     at package.WorkPatternDayCorePeriodsEJB_vd9y46_ELOImpl.remove(WorkPatternDayCorePeriodsEJB_vd9y46_ELOImpl.java:722)
     at package.PersonWorkPatternBC.removeWorkPatternDay(PersonWorkPatternBC.java:571)
     at package.remove(PersonWorkPatternBC.java:708)
     at package.TimPersonCalendarServiceEJB.removeWorkPattern(TimPersonCalendarServiceEJB.java:140)
</pre>
In fact I have this setup:
<pre>
workpattern 1..n workpatternday -| 1..n dayperiod
| 1..n daycoreperiod
</pre>
And before 'ejbRemove'ing the workpattern I first remove the days and before that the periods and core periods.
I start with the periods and instead of removing them in the DB he tries to update the FK to the day with '' (p6spy result).
When I remove the not null constraint on the foreign key everything passes to the day where the workpatternId cannot be set to null.
He does not throw errors on the coreperiod (where the not null constraint to day is still present).
When I invert the sequence of deleting
(first the core periods then the 'regular' periods) he complains about the dayId on the core periods table.
So it's completely absurd :S
I hope weblogic 8.1 might solve this problem as this development code is still to be migrated to 8.1 before going in production...
I would just like to know what's wrong. There are other places with just about the same relationships (CMR and DB) where he does not complain...

CMP Entity Beans read database row twice?

Here are two basic questions regarding container managed persistence Entity Beans:
How many database read operations are performed when a remote reference to a CMP Entity Bean is obtained by a client?
Is it correct, that each row is read twice?
For example if a have one row in a database which I want to lookup, AFAIK first the findByPrimaryKey method perfoms a select to lookup the primary key, and then the (container-)ejbLoad method actually reads the row a second time to populate the CMP fields of the bean.
And how often are UPDATE statements performed?
Is a database UPDATE statement performed each time a setXX method is invoked?
Thanks for any help,
Robert

How many database read operations are performed when a
remote reference to a CMP Entity Bean is obtained by a
client?
Is it correct, that each row is read twice?It all depends on the CMP system. A simple system might well hit the database twice, once to validate the primary key and once to load the object's fields. A
smarter system might try to cache the results from the first, so it didn't need to do the second (although this might be a bit dodgy from a transactional point of view).
However, a couple of facts about databases come in here. Firstly, the query to check the primary key doesn't actually need to load any data from the table: it just needs to check that the key exists. Thus, it should be possible to handle this query just using the index, not touching the table itself at all. Secondly, databases do their own caching, so if a row was loaded in the first query, there is a good chance that it would still be around for the second.
And how often are UPDATE statements performed?
Is a database UPDATE statement performed each time a
setXX method is invoked?Under CMP 1.1, UPDATES are typically done at the end of a transaction; if you use container-demarcated transactions, then yes, UPDATES will happen after every call. If the client code sets up its own transaction, then the UPDATE will only happen after several setXXX calls.
This can be a performance problem. A common solution is the use of coarse-grained detail objects:
http://java.sun.com/j2ee/blueprints/sample_application/model/ (section 10.4.1.2)

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

Error Deploying CMP Entity Bean

Hi,
I am new to Entity Beans and am trying to deploy a CMP Entity Bean without any success.
I did search this forum for similar issues and tried those suggestions as well but that has not helped. Was wondering if someone could help me out on this.
The Entity bean has 2 fields: name and description.
The ejb-jar.xml file for this bean is:
<enterprise-beans>
<entity>
<ejb-name>Product</ejb-name>
<home>example.cmp.ProductHome</home>
<remote>example.cmp.Product</remote>
<ejb-class>example.cmp.ProductBean</ejb-class>
<persistence-type>Container</persistence-type>
<prim-key-class>java.lang.String</prim-key-class>
<reentrant>false</reentrant>
<cmp-version>2.x</cmp-version>
<abstract-schema-name>PRODUCTS</abstract-schema-name>
<cmp-field>
<field-name>name</field-name>
</cmp-field>
<cmp-field>
<field-name>description</field-name>
</cmp-field>
<primkey-field>name</primkey-field>
<query>
</query>
</entity>
</enterprise-beans>
The error that I get while deploying the bean is:
Error deploying EJB homes for: file:/C:/servers/oc4j1013/j2ee/home/applications/cmptest/cmptest.jar
java.lang.InstantiationException: Error looking up cmt-datasource at jdbc/OracleDS (name not found)
at com.evermind.server.ApplicationState.getDataSourceContainer(ApplicationState.java:384)
Error deploying file:/C:/servers/oc4j1013/j2ee/home/applications/cmptest/cmptest.jar
homes: Error looking up cmt-datasource at jdbc/OracleDS (name not found)
[java] [TopLink Severe]: 2005.04.17 10:22:20.156--ServerSession(28816172)--
Local Exception Stack:
[java] Exception [TOPLINK-7060] (TopLink (Oracle OC4J CMP) - 10g release 3(10.1.3.0) (Build 041129)): oracle.toplink.exceptions.ValidationException
[java] Exception Description: Cannot acquire data source [jdbc/OracleDS].
[java] Internal Exception: javax.naming.NameNotFoundException: jdbc/OracleDS not found
[java] at oracle.toplink.exceptions.ValidationException.cannotAcquireDataSource(ValidationException.java:208)
[java] at oracle.toplink.internal.ejb.cmp.oc4j.Oc4jNonJtaConnector.getOrCreateDataSource(Oc4jNonJtaConnector.java:62)
If anybody knows what the problem is please let me know.
Thanks in advance.
Bhupen

Please note that the data-source has been re-architectured in 10.1.3 DP3 and you should have DataSource as follows:
<data-sources xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xsi:noNamespaceSchemaLocation='http://xmlns.oracle.com/oracleas/schema/data-sources-10_1.xsd' schema-major-version='10' schema-minor-version='1'>
<managed-data-source connection-pool-name='Example Connection Pool' jndi-name='jdbc/OracleDS' name='OracleManagedDS' />
<connection-pool name='Example Connection Pool' >
<connection-factory factory-class='oracle.jdbc.pool.OracleDataSource' user='scott' password='tiger' url='jdbc:oracle:thin:@localhost:1521:orcl'>
</connection-factory>
</connection-pool>
</data-sources>

RE: Consuming and Creating a CMP Entity Bean

Hi There,
I have been trying to find an answer for 1 day. I don't know ehre to look next.
I am creating a CMP entity bean. I have created all the set and get mehtods as abstract functions. I have added a ejbCreate and a matching ejbPostCreate. The class code looks like this.
public abstract class COrderBean implements EntityBean {
     protected EntityContext entctx;
     //abstract declarations of property accessors
     public abstract int getId();
     public abstract void setId(int intid);
     public abstract String getCustomerID();
     public abstract void setCustomerID(String strcustomerid);
     public abstract Date getDate();
     public abstract void setDate(Date datorder);
     public abstract String getNotes();
     public abstract void setNotes(String strnotes);
     public void ejbActivate() {}
     public void ejbPassivate() {}
     public void ejbRemove() {}
     public void ejbLoad() {}
     public void ejbStore() {}
     public void setEntityContext(EntityContext context)
          entctx = context;
     public void unsetEntityContext()
          entctx = null;
     public COrderPK ejbCreate()
          return null;
     public COrderPK ejbCreate(int new_id, String new_customerid, Date new_order_date, String new_notes) throws CreateException
          setId(new_id);
          setCustomerID(new_customerid);
          setDate(new_order_date);
          setNotes(new_notes);
          return new COrderPK(getId());
     public void ejbPostCreate(int id, String customerid, Date order_date, String notes) {}
My client code works with both BMP entity beans and session beans. It is shown below. I am working with Sun's Application Server 8.0 and I created the database schema with the capture-schema.exe command.
Properties prps = new Properties();
          props.put("javax.rmi.CORBA.UtilClass","com.sun.corba.ee.impl.javax.rmi.CORBA.Util");
          props.put("org.omg.CORBA.ORBClass","com.sun.corba.ee.impl.orb.ORBImpl");
          props.put("org.omg.CORBA.ORBSingletonClass","com.sun.corba.ee.impl.orb.ORBSingleton");
          Context context = new InitialContext(props);
          Object obj = context.lookup("corbaname:iiop:localhost:3700#COrderBean");
          //Object obj = context.lookup("entitybean.OrderItem");
               IOrderHome home = (IOrderHome)PortableRemoteObject.narrow(obj,Class.forName("ctaejb.entitybean.order.IOrderHome"));
               //use create
               IOrderRemote remote = home.findByPrimaryKey(new COrderPK(1));
               System.out.println(remote.getDate().toString());
I am getting the follwing error. Can someone please help. Thanks in advance.
WARNING: "IOP00810257: (MARSHAL) Could not find class"
org.omg.CORBA.MARSHAL: vmcid: SUN minor code: 257 completed: Maybe
     at com.sun.corba.ee.impl.logging.ORBUtilSystemException.couldNotFindClass(ORBUtilSystemException.java:7987)
     at com.sun.corba.ee.impl.encoding.CDRInputStream_1_0.read_value(CDRInputStream_1_0.java:1013)
     at com.sun.corba.ee.impl.encoding.CDRInputStream.read_value(CDRInputStream.java:259)
     at com.sun.corba.ee.impl.io.IIOPInputStream.inputObjectField(IIOPInputStream.java:1989)
     at com.sun.corba.ee.impl.io.IIOPInputStream.inputClassFields(IIOPInputStream.java:2213)
     at com.sun.corba.ee.impl.io.IIOPInputStream.inputObject(IIOPInputStream.java:1221)
     at com.sun.corba.ee.impl.io.IIOPInputStream.simpleReadObject(IIOPInputStream.java:400)
     at com.sun.corba.ee.impl.io.ValueHandlerImpl.readValueInternal(ValueHandlerImpl.java:330)
     at com.sun.corba.ee.impl.io.ValueHandlerImpl.readValue(ValueHandlerImpl.java:296)
     at com.sun.corba.ee.impl.encoding.CDRInputStream_1_0.read_value(CDRInputStream_1_0.java:1034)
     at com.sun.corba.ee.impl.encoding.CDRInputStream_1_0.read_value(CDRInputStream_1_0.java:879)
     at com.sun.corba.ee.impl.encoding.CDRInputStream.read_value(CDRInputStream.java:255)
     at com.sun.corba.ee.spi.servicecontext.UEInfoServiceContext.<init>(UEInfoServiceContext.java:30)
     at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
     at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
     at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
     at java.lang.reflect.Constructor.newInstance(Constructor.java:494)
     at com.sun.corba.ee.spi.servicecontext.ServiceContextData.makeServiceContext(ServiceContextData.java:114)
     at com.sun.corba.ee.spi.servicecontext.ServiceContexts.unmarshal(ServiceContexts.java:195)
     at com.sun.corba.ee.spi.servicecontext.ServiceContexts.get(ServiceContexts.java:365)
     at com.sun.corba.ee.spi.servicecontext.ServiceContexts.get(ServiceContexts.java:353)
     at com.sun.corba.ee.impl.protocol.CorbaClientRequestDispatcherImpl.processResponse(CorbaClientRequestDispatcherImpl.java:470)
     at com.sun.corba.ee.impl.protocol.CorbaClientRequestDispatcherImpl.marshalingComplete(CorbaClientRequestDispatcherImpl.java:327)
     at com.sun.corba.ee.impl.protocol.CorbaClientDelegateImpl.invoke(CorbaClientDelegateImpl.java:158)
     at com.sun.corba.ee.impl.presentation.rmi.StubInvocationHandlerImpl.invoke(StubInvocationHandlerImpl.java:129)
     at com.sun.corba.ee.impl.presentation.rmi.bcel.BCELStubBase.invoke(Unknown Source)
     at ctaejb.entitybean.order._IOrderHome_DynamicStub.findByPrimaryKey(_IOrderHome_DynamicStub.java)
     at mainapp.CTestApplication.main(CTestApplication.java:32)
Caused by: java.lang.ClassNotFoundException
     ... 27 more
org.omg.CORBA.UNKNOWN: vmcid: 0x0 minor code: 0 completed: Maybe
     at com.sun.corba.ee.spi.servicecontext.UEInfoServiceContext.<init>(UEInfoServiceContext.java:34)
     at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
     at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
     at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
     at java.lang.reflect.Constructor.newInstance(Constructor.java:494)
     at com.sun.corba.ee.spi.servicecontext.ServiceContextData.makeServiceContext(ServiceContextData.java:114)
     at com.sun.corba.ee.spi.servicecontext.ServiceContexts.unmarshal(ServiceContexts.java:195)
     at com.sun.corba.ee.spi.servicecontext.ServiceContexts.get(ServiceContexts.java:365)
     at com.sun.corba.ee.spi.servicecontext.ServiceContexts.get(ServiceContexts.java:353)
     at com.sun.corba.ee.impl.protocol.CorbaClientRequestDispatcherImpl.processResponse(CorbaClientRequestDispatcherImpl.java:470)
     at com.sun.corba.ee.impl.protocol.CorbaClientRequestDispatcherImpl.marshalingComplete(CorbaClientRequestDispatcherImpl.java:327)
     at com.sun.corba.ee.impl.protocol.CorbaClientDelegateImpl.invoke(CorbaClientDelegateImpl.java:158)
     at com.sun.corba.ee.impl.presentation.rmi.StubInvocationHandlerImpl.invoke(StubInvocationHandlerImpl.java:129)
     at com.sun.corba.ee.impl.presentation.rmi.bcel.BCELStubBase.invoke(Unknown Source)
     at ctaejb.entitybean.order._IOrderHome_DynamicStub.findByPrimaryKey(_IOrderHome_DynamicStub.java)
     at mainapp.CTestApplication.main(CTestApplication.java:32)

Forget it. All the code works. I didn't know that the Sun App Server required a Persistence Manager to work with CMP entity beans. Once I added the persistence manager, all was OK. Have a good day.

Help:How to manage relationships in CMP Entity beans

Similar Messages

Maybe you are looking for