Please check this ejb-jar.xml, weblogic-ejb-jar.xml,weblogic-cmp-rdbms.xml

Question

i am getting a classcast exception.My Stateless and stateful session bean works
fine .. problem only with Entity bean. Please check these xml files and let me
know if i have missed anything.
ejb-jar.xml
<?xml version="1.0"?>
<!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>
<enterprise-beans>
<entity>
<ejb-name>stores</ejb-name>
<home>Ejb.Stores.storesHome</home>
<remote>Ejb.Stores.storesRemote</remote>
<ejb-class>Ejb.Stores.storesBean</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>storesBean</abstract-schema-name>
<cmp-field>
<field-name>productId</field-name>
</cmp-field>
<cmp-field>
<field-name>descrip</field-name>
</cmp-field>
<cmp-field>
<field-name>price</field-name>
</cmp-field>
<primkey-field>productId</primkey-field>
<query>
<query-method>
<method-name>findPriceGreaterThan</method-name>
<method-params>
<method-param>double</method-param>
</method-params>
</query-method>
<ejb-ql>
<![CDATA[SELECT OBJECT(a) FROM storesBean AS a WHERE a.price > ?1]]>
</ejb-ql>
</query>
</entity>
</enterprise-beans>
<assembly-descriptor>
<container-transaction>
<method>
<ejb-name>stores</ejb-name>
     <method-name>*</method-name>
</method>
<trans-attribute>Required</trans-attribute>
</container-transaction>
</assembly-descriptor>
</ejb-jar>
------------- end of ejb-ar.xml---------------------
weblogic-jar.xml
<?xml version="1.0"?>
<!DOCTYPE weblogic-ejb-jar PUBLIC "-//BEA Systems, Inc.//DTD WebLogic 6.0.0 EJB//EN"
"http://www.bea.com/servers/wls600/dtd/weblogic-ejb-jar.dtd" >
<weblogic-ejb-jar>
<weblogic-enterprise-bean>
<ejb-name>stores</ejb-name>
<entity-descriptor>
<persistence>
<persistence-type>
     <type-identifier>WebLogic_CMP_RDBMS</type-identifier>
     <type-version>6.0</type-version>
     <type-storage>META-INF/weblogic-cmp-rdbms-jar.xml</type-storage>
     </persistence-type>
     <persistence-use>
     <type-identifier>WebLogic_CMP_RDBMS</type-identifier>
     <type-version>6.0</type-version>
     </persistence-use>
</persistence>
</entity-descriptor>
<jndi-name>storesEntity</jndi-name>
</weblogic-enterprise-bean>
</weblogic-ejb-jar>
------------- end of weblogic-jar.xml----------
weblogic-cmp-rdbms-jar.xml
<!DOCTYPE weblogic-rdbms-jar PUBLIC '-//BEA Systems, Inc.//DTD WebLogic 6.0.0
EJB RDBMS Persistence//EN' 'http://www.bea.com/servers/wls600/dtd/weblogic-rdbms20-persistence-600.dtd'>
<weblogic-rdbms-jar>
<weblogic-rdbms-bean>
<ejb-name>stores</ejb-name>
<data-source-name>sqlTX</data-source-name>
<table-name>ProductEJBTable</table-name>
<field-map>
<cmp-field>productId</cmp-field>
<dbms-column>productId</dbms-column>
</field-map>
<field-map>
<cmp-field>descrip</cmp-field>
<dbms-column>descrip</dbms-column>
</field-map>
<field-map>
<cmp-field>price</cmp-field>
<dbms-column>price</dbms-column>
</field-map>
</weblogic-rdbms-bean>
<create-default-dbms-tables>false</create-default-dbms-tables>
</weblogic-rdbms-jar>
---------------- end of weblogic-cmp-rdbms-jar.xml----------
Do i have to mention the connection Pool name anywhere .. My connection Pool name
is sql7Pool and my datasource name which i have mentioned is sqlTx. I am using
Sql server 7. I am deploying a jar file(not a war file) and accessng the EJB through
a Servlet. Please any help would definitely be appreciated.
Cheers
Ashish.

Answer 1

I thought you were getting a class cast exception but the stack trace shows
a NullPointerException on line 38 of your servlet code. I am not sure if the
code that you have attached is the complete code or just snippets of your
complete code. Anyways, counting 38 lines in the code you attached points to
the line "mr =
mh.create(request.getParameter("login"),request.getParameter("name"));"
which could be because "mh" is null. Can you verify "mh" is not null and
also "objRef" is not null.
Attaching the stack trace for ClassCastException would be useful.
-- Anand
"Ashish Suvarna" <[email protected]> wrote in message
news:[email protected]...
>
Hey Anand,
Thanks for your reply. I have attached the StackTrace,Servlet code andmy
location and settings of my servlet .
This is the StackTrace which i get :
pl.java:265)
atweblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubIm
pl.java:200)
atweblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppSe
rvletContext.java:2495)
atweblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestIm
pl.java:2204)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
before create
java.lang.NullPointerException
at trialweblogic.webServlet.doGet(webServlet.java:38)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
atweblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubIm
pl.java:265)
atweblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubIm
pl.java:200)
atweblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppSe
rvletContext.java:2495)
atweblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestIm
pl.java:2204)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
-------------- end of StackTrace---------------------
My Servlet Code is
package trialweblogic;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import java.sql.*;
import javax.naming.InitialContext;
import javax.rmi.PortableRemoteObject;
import javax.ejb.ObjectNotFoundException;
import javax.ejb.DuplicateKeyException;
import javax.ejb.EJBException;
import java.rmi.RemoteException;
import java.rmi.Remote;
import trialweblogic.*;
public class webServlet extends HttpServlet {
masterHome mh;
masterRemote mr;
OutputStream out;
private static final String CONTENT_TYPE = "text/html";
public void init(ServletConfig config) throws ServletException {
super.init(config);
public void doGet(HttpServletRequest request, HttpServletResponseresponse)
throws ServletException, IOException {
response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter();
// out = response.getOutputStream();
try{
InitialContext ic = new InitialContext();
Object objRef = ic.lookup("masterBeanJNDI");
mh =(masterHome)PortableRemoteObject.narrow(objRef,masterHome.class);
>
mr =mh.create(request.getParameter("login"),request.getParameter("name"));
out.println("after create");
}catch(Exception ex){
ex.printStackTrace();
public void destroy() {
--------- end of servlet--------------
I am using Weblogic 6.1. I have included the following in my web.xml filewhich
is located atC:\bea\wlserver6.1\config\examples\applications\examplesWebApp\WEB-INF
>
>
<servlet>
<servlet-name>webServlet</servlet-name>
<servlet-class>trialweblogic.webServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>webServlet</servlet-name>
<url-pattern>/webServlet/*</url-pattern>
</servlet-mapping>
My Servlet is located atC:\bea\wlserver6.1\config\examples\applications\examplesWebApp\WEB-INF\class
es\trialweblogic\
folder. In this folder i also have the supporting files (home,remote &bean tooo).
>
>
I call this servlet when te user submits the info from a JSP page.
Hope this info helps in solving my problem. Do i have to mention theconnection
Pool name anywhere in the xml descriptor or am i missing anything here. iguess
Connection Pool name is not required since we are mentioning the JNDI namein
the xml descriptor. Bye for now.Awaiting your reply.
Cheers
Ashish.
"Anand Byrappagari" <[email protected]> wrote:
It is unlikely that your xml descriptors can cause class cast exceptions.
How did you install the servlet? Can you attach the servlet code that
might
help. Also complete stack trace of the exceptions would be helpful.
-- Anand
"Ashish Suvarna" <[email protected]> wrote in message
news:[email protected]...
Hi Anand,
Thanks for quic reply.Hey i am using weblogic6.1. I am Not usinga WAR
and
ear file.I have created a jar file and deployed it.now i have createda
servlet
to access entity bean.Is a war file neccessary for accesing an entitybean
through
Servlet or JSP ???I am using sql server 7. The error that it givesis -----
java.lang.ClassCastException: Cannot narrow remote object<br>
"inside lookup method aaaaaaa" java.lang.NullPointerException. <br>
Hope to get ur reply soon. in another entity bean i am getting thiserror ---
java.lang.ClassCastException:
weblogic.jdbc.common.internal.RmiDataSource
.. I
can't understand wots this error. I feel i am missing something inmy xml
descriptor.
Bye for now.
Cheers
Ashish.
"Anand Byrappagari" <[email protected]> wrote:
Can you attach the stack trace for the exception? Also please describe
you
environment - are the war and jar files installed separately? Are
they
composed into a ear? Also when are you getting a classcast exception?
-- Anand
"Ashish Suvarna" <[email protected]> wrote in message
news:[email protected]...
i am getting a classcast exception.My Stateless and stateful sessionbean
works
fine .. problem only with Entity bean. Please check these xml filesand
let me
know if i have missed anything.
ejb-jar.xml
<?xml version="1.0"?>
<!DOCTYPE ejb-jar PUBLIC "-//Sun Microsystems, Inc.//DTD EnterpriseJavaBeans
2.0//EN" "http://java.sun.com/dtd/ejb-jar_2_0.dtd">
<ejb-jar>
<enterprise-beans>
<entity>
<ejb-name>stores</ejb-name>
<home>Ejb.Stores.storesHome</home>
<remote>Ejb.Stores.storesRemote</remote>
<ejb-class>Ejb.Stores.storesBean</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>storesBean</abstract-schema-name>
<cmp-field>
<field-name>productId</field-name>
</cmp-field>
<cmp-field>
<field-name>descrip</field-name>
</cmp-field>
<cmp-field>
<field-name>price</field-name>
</cmp-field>
<primkey-field>productId</primkey-field>
<query>
<query-method>
<method-name>findPriceGreaterThan</method-name>
<method-params>
<method-param>double</method-param>
</method-params>
</query-method>
<ejb-ql>
<![CDATA[SELECT OBJECT(a) FROM storesBean AS a WHERE
a.price> >> >>> >> >?1]>
</ejb-ql>
</query>
</entity>
</enterprise-beans>
<assembly-descriptor>
<container-transaction>
<method>
<ejb-name>stores</ejb-name>
<method-name>*</method-name>
</method>
<trans-attribute>Required</trans-attribute>
</container-transaction>
</assembly-descriptor>
</ejb-jar>
------------- end of ejb-ar.xml---------------------
weblogic-jar.xml
<?xml version="1.0"?>
<!DOCTYPE weblogic-ejb-jar PUBLIC "-//BEA Systems, Inc.//DTD
WebLogic
6.0.0 EJB//EN"
"http://www.bea.com/servers/wls600/dtd/weblogic-ejb-jar.dtd" >
<weblogic-ejb-jar>
<weblogic-enterprise-bean>
<ejb-name>stores</ejb-name>
<entity-descriptor>
<persistence>
<persistence-type>
<type-identifier>WebLogic_CMP_RDBMS</type-identifier>
<type-version>6.0</type-version>
<type-storage>META-INF/weblogic-cmp-rdbms-jar.xml</type-storage>
</persistence-type>
<persistence-use>
<type-identifier>WebLogic_CMP_RDBMS</type-identifier>
<type-version>6.0</type-version>
</persistence-use>
</persistence>
</entity-descriptor>
<jndi-name>storesEntity</jndi-name>
</weblogic-enterprise-bean>
</weblogic-ejb-jar>
------------- end of weblogic-jar.xml----------
weblogic-cmp-rdbms-jar.xml
<!DOCTYPE weblogic-rdbms-jar PUBLIC '-//BEA Systems, Inc.//DTD
WebLogic
6.0.0
EJB RDBMS Persistence//EN'
'http://www.bea.com/servers/wls600/dtd/weblogic-rdbms20-persistence-600.dt
d
<weblogic-rdbms-jar>
<weblogic-rdbms-bean>
<ejb-name>stores</ejb-name>
<data-source-name>sqlTX</data-source-name>
<table-name>ProductEJBTable</table-name>
<field-map>
<cmp-field>productId</cmp-field>
<dbms-column>productId</dbms-column>
</field-map>
<field-map>
<cmp-field>descrip</cmp-field>
<dbms-column>descrip</dbms-column>
</field-map>
<field-map>
<cmp-field>price</cmp-field>
<dbms-column>price</dbms-column>
</field-map>
</weblogic-rdbms-bean>
<create-default-dbms-tables>false</create-default-dbms-tables>
</weblogic-rdbms-jar>
---------------- end of weblogic-cmp-rdbms-jar.xml----------
Do i have to mention the connection Pool name anywhere .. My
connection
Pool name
is sql7Pool and my datasource name which i have mentioned is sqlTx.I am
using
Sql server 7. I am deploying a jar file(not a war file) and accessngthe
EJB through
a Servlet. Please any help would definitely be appreciated.
Cheers
Ashish.