OTN developers have implemented the Virtual Shopping Mall 1.3, a sample application that demonstrates the various features of the J2EE platform. The VSM 1.3 enables vendors to set up online shops and customers to browse through these shops. It also enables a system administrator to approve/reject requests for new shops and maintain a list of shop categories. Some of the features that we intend to highlight through this application include:

* J2EE Design Patterns
* Internationalization Techniques
* Apache Struts Framework
* Security Features using JAAS

We have put together a series of tutorials that uses the Virtual Shopping Mall 1.3 sample application to demonstrate programming techniques that take advantage of features defined in the J2EE 1.3(EJB 2.0, Servlet 2.3 etc) specifications. While describing parts of the larger application, each tutorial is self-contained, and explains how to use a technique or perform a task.

The sample application has been certified on Oracle Application Server Containers for J2EE 10g on Windows 2000 and Red Hat Linux Advanced Server 2.1 platforms.

I wonder how long till someone does a .Net versus J2EE version of this...

Billy (blog)

cool one and useful.

Excellent Application, well done OTN!!

The VSM application is a role model for engineering a J2EE application. Along with the accompanying tutorial, the VSM app will serve as a good mentor for J2EE developers.

Arun Sreekumar S

Why did they use STRUTS instead of BC4J ?

Hi,
  We do have a BC4J version of the same application. Check this out
Infact, BC4J also extends struts by subclassing the RequestProcessor of Struts.
  The idea of VSM 1.3 is to demonstrate writing an end-to-end application using J2EE technologies. Though BC4J itself is pure Java, one has to learn the BC4J framework,whereas VSM 1.3 uses the standard J2EE technologies and the popular Struts framework.
Hope this clears your doubt.
rehards

How much of this excellent example is specific to Oracle?

Hi,
   Virtually none. The application uses Oracle XSQL Servlets for report generation.But this can be treated as a library,(can be downloaded from http://otn.oracle.com/tech/xml/xdkhome.html), just like the Apache FOP libraries used by the application.
    Another area which uses Oracle APIs is JAAS user management(JAZN-Oracle's JAAS provider implementation). But it is abstracted and the specific classes can be omitted (note: not 'changed',but simply removed) while deploying to other app servers.
Hope this helps,
regards,
Neelesh

Is this application specific to Oracle AS?

I tried to deploy the generated VSM.ear into EA Server and ran into
several deployment problems related to oracle:


Deploying Web Components from bundle VSMWeb
Caught Exception: {0}
com.sybase.jaguar.util.JException: Invalid servlet name: oracle.otnsamples.ws.CC
ServicesImpl
        at com.sybase.jaguar.management.JServletImpl.<init>(JServletImpl.java:70
)
        at com.sybase.jaguar.management.JWebApplicationImpl.createServlet(JWebAp
plicationImpl.java:308)
        at com.sybase.jaguar.importer.JEarImporter.installWebComponentsinJaguar(
JEarImporter.java:2859)
        at com.sybase.jaguar.importer.JEarImporter.deployWebAppBundle(JEarImport
er.java:770)
        at com.sybase.jaguar.management.deploytool.EarImporterCallClass.run(EarI
mporterCallClass.java:434)
        at java.lang.Thread.run(Thread.java:484)

com.sybase.jaguar.util.JException: Invalid servlet name: oracle.otnsamples.ws.CC
ServicesImpl
        at com.sybase.jaguar.importer.JEarImporter.deployWebAppBundle(JEarImport
er.java:804)
        at com.sybase.jaguar.management.deploytool.EarImporterCallClass.run(EarI
mporterCallClass.java:434)
        at java.lang.Thread.run(Thread.java:484)


Is this not a standard J2ee compatible application/ear?

Thanks!

Hi
  This is a standard J2EE application, only that while you are deploying the app on other application servers, certain utility libraries (like you would add Apache's or any other application specific libs) need to be added to WEB-INF/lib folder of the application.
  In this case, the application uses Oracle's web service implementation, using which a java class can be exposed as a web service. So the libraries you need are under <OC4J_HOME>/webservices/lib folder. You can get ocj4 from http://otn.oracle.com/products/ias/index.html
   I haven't tried this yet, but this should work.
Please feel free to post your queries/problems/suggestions on this application, either here or http://www.oracle.com/forums/forum.jsp?forum=133 which is meant for resolving issues on sample application developed by OTN.
Hope this helps,
Thanks,
Neelesh

I downloaded oc4j 10g and Apache struts and could compile and
deploy successfully to OC4J. I tried deploying the generated
VSM.ear to EA Server and ran into the errors I mentioned earlier.
Is this is the right method? I used build.xml that is bundled with
the tutorial.

I tried modifying the build.xml to point to EA Server, but that failed
at the deployment stage with the following errors:


oc4j-ear:
      [ear] Building ear: /work1/testarea/vsm-i18n/classes/VSM.ear
   [delete] Deleting: /work1/testarea/vsm-i18n/classes/VSMWeb.war
   [delete] Deleting: /work1/testarea/vsm-i18n/classes/VSMEJB.jar
     [move] Moving 1 files to /work1/testarea/vsm-i18n

deploy-oc4j:
     [java] Error: Unable to find java:comp/ServerAdministrator: Lookup error: j
ava.io.EOFException: Disconnected; nested exception is:
     [java] java.io.EOFException: Disconnected
     [java] com.evermind.client.orion.AdminCommandException: Unable to find java
:comp/ServerAdministrator: Lookup error: java.io.EOFException: Disconnected; nes
ted exception is:
     [java] java.io.EOFException: Disconnected
     [java] at com.evermind.client.orion.Oc4jAdminConsole.executeCommand(Oc4
jAdminConsole.java:104)
     [java] at com.evermind.client.orion.Oc4jAdminConsole.main(Oc4jAdminCons
ole.java:26)
     [java] javax.naming.NamingException: Lookup error: java.io.EOFException: Di
sconnected; nested exception is:
     [java] java.io.EOFException: Disconnected. Root exception is java.io.E
OFException: Disconnected
     [java] at com.evermind.server.rmi.RMIConnection.connect(RMIConnection.j
ava:2263)
     [java] at com.evermind.server.rmi.RMIConnection.connect(RMIConnection.j
ava:2128)
     [java] at com.evermind.server.rmi.RMIConnection.lookup(RMIConnection.ja
va:1672)
     [java] at com.evermind.server.rmi.RMIServer.lookup(RMIServer.java:702)
     [java] at com.evermind.server.rmi.RMIContext.lookup(RMIContext.java:100
)
     [java] at com.evermind.client.orion.Oc4jAdminConsole.executeCommand(Oc4
jAdminConsole.java:101)
     [java] at com.evermind.client.orion.Oc4jAdminConsole.main(Oc4jAdminCons
ole.java:26)
     [java] ---- Embedded exception
     [java] java.io.EOFException: Disconnected
     [java] at com.evermind.server.rmi.RMIConnection.connect(RMIConnection.j
ava:2263)
     [java] at com.evermind.server.rmi.RMIConnection.connect(RMIConnection.j
ava:2128)
     [java] at com.evermind.server.rmi.RMIConnection.lookup(RMIConnection.ja
va:1672)
     [java] at com.evermind.server.rmi.RMIServer.lookup(RMIServer.java:702)
     [java] at com.evermind.server.rmi.RMIContext.lookup(RMIContext.java:100
)
     [java] at com.evermind.client.orion.Oc4jAdminConsole.executeCommand(Oc4
jAdminConsole.java:101)
     [java] at com.evermind.client.orion.Oc4jAdminConsole.main(Oc4jAdminCons
ole.java:26)
     [java] Java Result: 3
     [java] Error: Unable to find java:comp/ServerAdministrator: Lookup error: j
ava.io.EOFException: Disconnected; nested exception is:
     [java] java.io.EOFException: Disconnected
     [java] com.evermind.client.orion.AdminCommandException: Unable to find java
:comp/ServerAdministrator: Lookup error: java.io.EOFException: Disconnected; nes
ted exception is:
     [java] java.io.EOFException: Disconnected
     [java] at com.evermind.client.orion.Oc4jAdminConsole.executeCommand(Oc4
jAdminConsole.java:104)
     [java] at com.evermind.client.orion.Oc4jAdminConsole.main(Oc4jAdminCons
ole.java:26)
     [java] javax.naming.NamingException: Lookup error: java.io.EOFException: Di
sconnected; nested exception is:
     [java] java.io.EOFException: Disconnected. Root exception is java.io.E
OFException: Disconnected
     [java] at com.evermind.server.rmi.RMIConnection.connect(RMIConnection.j
ava:2263)
     [java] at com.evermind.server.rmi.RMIConnection.connect(RMIConnection.j
ava:2128)
     [java] at com.evermind.server.rmi.RMIConnection.lookup(RMIConnection.ja
va:1672)
     [java] at com.evermind.server.rmi.RMIServer.lookup(RMIServer.java:702)
     [java] at com.evermind.server.rmi.RMIContext.lookup(RMIContext.java:100
)
     [java] at com.evermind.client.orion.Oc4jAdminConsole.executeCommand(Oc4
jAdminConsole.java:101)
     [java] at com.evermind.client.orion.Oc4jAdminConsole.main(Oc4jAdminCons
ole.java:26)
     [java] ---- Embedded exception
     [java] java.io.EOFException: Disconnected
     [java] at com.evermind.server.rmi.RMIConnection.connect(RMIConnection.j
ava:2263)
     [java] at com.evermind.server.rmi.RMIConnection.connect(RMIConnection.j
ava:2128)
     [java] at com.evermind.server.rmi.RMIConnection.lookup(RMIConnection.ja
va:1672)
     [java] at com.evermind.server.rmi.RMIServer.lookup(RMIServer.java:702)
     [java] at com.evermind.server.rmi.RMIContext.lookup(RMIContext.java:100
)
     [java] at com.evermind.client.orion.Oc4jAdminConsole.executeCommand(Oc4
jAdminConsole.java:101)
     [java] at com.evermind.client.orion.Oc4jAdminConsole.main(Oc4jAdminCons
ole.java:26)
     [java] Java Result: 3

BUILD SUCCESSFUL
Total time: 33 seconds



















" Error: Unable to find java:comp

Hi,
Although what you are doing is logically correct, J2EE applications doesnt work as they are....ie., minor application server specific modifications has to be done in order to make the J2EE application run across different servers.

For example, in your case, the application fails at JNDI layer. ie., the default JNDI lookup mechanism in the application tries to load OC4J specific classes and it fails when it didnt find them...You need to modify the jndi.properties in the config directory to make the JNDI layer work.

Similarly you may need to change the orion-ejb-jar.xml in src/META-INF directory according to your EA server specific deployment descriptor. If you want to deploy this in weblogic then you need to come with weblogic-ejb-jar.xml...etc

But there is no code change needed for deploying across application servers provided you are not using any server specific API's and your application is J2EE compliant.

If you want know more information about porting J2EE applications, have a look at the following article which discuss about porting and cluster enabling this very theserverside.com across different app. servers.
http://www.theserverside.com/resources/article.jsp?l=tsscluster1

Cheers
--Venky

Thanks for the reply.

After making necessary modifications to the JNDI layer and deployment
descriptors, deployment to EA server went through fine.

However while trying to access the application from the browser:

http://hostname:http_port#/vsm/home.do

the application fails with the following message on the browser:

500 Servletaction:unable to service request::XML - 20220: (Fatal Error)

Is this something to do with the XML parser. I am using xerces.jar for
XML parsing.

The app server log has the following errors (in case you are interested):
Sep 23 13:13:51 2003: action: init
Sep 23 13:14:19 2003: 060038-Error: Unable to service request for servlet: actio
n.
Sep 23 13:14:19 2003: 060039-Error: ServletException contained the following roo
t cause exception:
org.xml.sax.SAXParseException: : XML-20220: (Fatal Error) Invalid InputSource.
        at oracle.xml.parser.v2.XMLError.flushErrorHandler(XMLError.java:262)
        at oracle.xml.parser.v2.XMLError.flushErrors1(XMLError.java:207)
        at oracle.xml.parser.v2.XMLReader.pushXMLReader(XMLReader.java:227)
        at oracle.xml.parser.v2.XMLParser.parse(XMLParser.java:174)
        at org.apache.commons.digester.Digester.parse(Digester.java:1567)
:1433) at org.apache.struts.action.ActionServlet.initServlet(ActionServlet.java
        at org.apache.struts.action.ActionServlet.init(ActionServlet.java:466)
        at javax.servlet.GenericServlet.init(GenericServlet.java:258)
        at com.sybase.jaguar.servlet.JagServlet.init(JagServlet.java:171)
etPool.java:173)ybase.jaguar.servlet.ServletPool.createInitializedInstance(Servl
) at com.sybase.jaguar.servlet.ServletPool.getInstance(ServletPool.java:72
atcher.java:868)ybase.jaguar.servlet.JagRequestDispatcher.service(JagRequestDisp
90) at com.sybase.jaguar.servlet.JagWebResource.service(JagWebResource.java:
:133) at com.sybase.jaguar.servlet.JagFilterChain.doFilter(JagFilterChain.java
:100) at oracle.otnsamples.vsm.HitCounterFilter.doFilter(HitCounterFilter.java
:107) at com.sybase.jaguar.servlet.JagFilterChain.doFilter(JagFilterChain.java
        at oracle.otnsamples.vsm.HeaderFilter.doFilter(HeaderFilter.java:220)
:107) at com.sybase.jaguar.servlet.JagFilterChain.doFilter(JagFilterChain.java
04) at com.sybase.jaguar.servlet.ServletEngine._service(ServletEngine.java:8
8) at com.sybase.jaguar.servlet.ServletEngine.service(ServletEngine.java:33
Impl.java:58)m.sybase.jaguar.servlet.ServletServiceImpl.doService(ServletService
_JaguarServlet_ServletService.java:143)k_JaguarServlet_ServletService.invoke(_sk

I have the same problem but when I try to create a Digester Class on the server side. It seems to be that Degister creates a XMLParser and it's throw an Exception...

Do you've solved the problem? What do you do?

Thanks.-