TRANSACTION ROLLBACK EXCEPTION:null

Hi all,
I am trying to use Composite primary key in CMP Beans With JBoss And Tomcat .When I call create method it gives me the following exception............
Kindly suggest the reasons and solutions.
server output.........
[PIDETAIL] TRANSACTION ROLLBACK EXCEPTION:null
Embedded Exception
null; nested exception is:
javax.ejb.EJBException: null
Embedded Exception
null
[PIDETAIL] java.lang.NullPointerException
[PIDETAIL] at org.jboss.ejb.plugins.jaws.jdbc.JDBCCreateEntityCommand.execute(JDBCCreateEn
tityCommand.java:111)
[PIDETAIL] at org.jboss.ejb.plugins.jaws.JAWSPersistenceManager.createEntity(JAWSPersisten
ceManager.java:128)
[PIDETAIL] at org.jboss.ejb.plugins.CMPPersistenceManager.createEntity(CMPPersistenceManag
er.java:231)
[PIDETAIL] at org.jboss.ejb.EntityContainer.createHome(EntityContainer.java:616)
[PIDETAIL] at java.lang.reflect.Method.invoke(Native Method)
[PIDETAIL] at org.jboss.ejb.EntityContainer$ContainerInterceptor.invokeHome(EntityContaine
r.java:843)
[PIDETAIL] at org.jboss.ejb.plugins.EntitySynchronizationInterceptor.invokeHome(EntitySync
hronizationInterceptor.java:231)
[PIDETAIL] at org.jboss.ejb.plugins.EntityInstanceInterceptor.invokeHome(EntityInstanceInt
erceptor.java:154)
[PIDETAIL] at org.jboss.ejb.plugins.EntityLockInterceptor.invokeHome(EntityLockInterceptor
.java:108)
[PIDETAIL] at org.jboss.ejb.plugins.TxInterceptorCMT.invokeNext(TxInterceptorCMT.java:135)
[PIDETAIL] at org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInterceptorCMT.
java:307)
[PIDETAIL] at org.jboss.ejb.plugins.TxInterceptorCMT.invokeHome(TxInterceptorCMT.java:86)
[PIDETAIL] at org.jboss.ejb.plugins.SecurityInterceptor.invokeHome(SecurityInterceptor.jav
a:103)
[PIDETAIL] at org.jboss.ejb.plugins.LogInterceptor.invokeHome(LogInterceptor.java:106)
[PIDETAIL] at org.jboss.ejb.EntityContainer.invokeHome(EntityContainer.java:420)
[PIDETAIL] at org.jboss.ejb.plugins.jrmp.server.JRMPContainerInvoker.invokeHome(JRMPContai
nerInvoker.java:370)
[PIDETAIL] at java.lang.reflect.Method.invoke(Native Method)
[PIDETAIL] at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:241)
[PIDETAIL] at sun.rmi.transport.Transport$1.run(Transport.java:142)
[PIDETAIL] at java.security.AccessController.doPrivileged(Native Method)
[PIDETAIL] at sun.rmi.transport.Transport.serviceCall(Transport.java:139)
[PIDETAIL] at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:443)
[PIDETAIL] at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:6
43)
[PIDETAIL] at java.lang.Thread.run(Thread.java:484)

And I am having such xml descriptors as follows
This is my ejb-jar xml.......
-----------------------------------ejb-jar.xml--------------------------------------------
<ejb-jar>
<enterprise-beans>
<entity>
<ejb-name>PIDETAIL</ejb-name>
<home>examples.trial.detail.PIDetailHome</home>
<remote>examples.trial.detail.PIDetail</remote>
<ejb-class>examples.trial.detail.PIDetailBean</ejb-class>
<persistence-type>Container</persistence-type>
<prim-key-class>examples.trial.detail.PIDetailPK</prim-key-class>
<reentrant>False</reentrant>
...................
...................
</entity>
</enterprise-beans>
<assembly-descriptor>
<container-transaction>
<method>
<ejb-name>PIDETAIL</ejb-name>
<method-intf>Remote</method-intf>
<method-name>*</method-name>
</method>
<trans-attribute>Required</trans-attribute>
</container-transaction>
</assembly-descriptor>
</ejb-jar>
-------------------------------------------- --------------------------------------------
And my jaws.xml file as follows...................
--------------------------------------------jaws.xml------------------------------------------
<jaws>
<datasource>java:/OraclePool</datasource>
<enterprise-beans>
<entity>
<ejb-name>PIDETAIL</ejb-name>
<table-name>PU_PO_DETAIL</table-name>
<create-table>true</create-table>
<cmp-field>
<field-name>poNo</field-name>
<column-name>PONO</column-name>
</cmp-field>
<cmp-field>
<field-name>po_Srno</field-name>
<column-name>PO_SRNO</column-name>
</cmp-field>
<cmp-field>
<field-name>revision_No</field-name>
<column-name>REVISION_NO</column-name>
</cmp-field>
...................
...................
<primkey-field>poNo</primkey-field>
<primkey-field>po_Srno</primkey-field>
<primkey-field>revision_No</primkey-field>
</entity>
</enterprise-beans>
</jaws>
-----------------------------------------------------
Thease are my composite key.
PoNo, po_Srno, revision_No.
---------------------------PK class ---------------
package examples.trial.detail;
import java.io.*;
public class PIDetailPK implements Serializable
{
public String poNo;//fk
public int po_Srno; //pk
public int revision_No;//fk
public PIDetailPK()
{
}
public PIDetailPK(String poNo,int po_Srno,int revision_No)
{
this.poNo = poNo;
this.po_Srno = po_Srno;
this.revision_No = revision_No;
}
public boolean equals(Object ThisKey)
{
if( ThisKey == null | | !(ThisKey instanceof PIDetailPK) )
return false ;
PIDetailPK pk = (PIDetailPK)ThisKey ;
if( (this.poNo.equals(pk.poNo)) && (this.revision_No == pk.revision_No) && (this.po_Srno == pk.po_Srno))
return true ;
return false ;
}
public int hashCode()
{
return ((this.toString()).hashCode()) ;
}
public String toString()
{
StringBuffer sb = new StringBuffer();
sb.append(poNo);
sb.append(revision_No);
sb.append(po_Srno);
return (sb.toString());
}
}
*************************************** **************

[This message has been edited by gajanan deshpande (edited October 04, 2001).]