Solved

trying to call an ejb from a servlet-client

Posted on 2002-04-15
4
361 Views
Last Modified: 2013-12-10
sir,

I am just a biginner in weblogic and I am facing a problem here and I think you will provide a nice solution to me .
Environment : J2EE/weblogic 5.1/ejb1.1/servlets/win'2000

I have successfuly deployed a stateless session bean named as "Game" and the jndi name used is "gum" at Weblogic 5.1.
Elements inside the "Game.jar" are :
remote interface-> Game.class
home interface  -> GameHome.class
bean class      -> GameBean.class
xml DD          -> META-INF/ejb-jar.xml

I have maintained the dir. structure as follows :  WEB-INF/lib /Game.jar
WEB-INF/classes/toy/*.class
WEB-INF/classes/toy/META-INF/ejb-jar.xml
and using a client servlet class "GameServ.class"
WEB-INF/classes/toy/GameServ.class

Now till I think everything is all right...
Now i started the weblogic...then called the index page
and from the index page I am calling the bean using the mentioned servlet client "GameServ.class" and during calling process i am getting a exception "java.lang.ClassCastException" at the line mentioned below inside ClentServ.class..>
line of error-->"GameHome sh=(GameHome) PortableRemoteObject.narrow(ref,GameHome.class);"

I tried my best but i could not get out of this problem and for more clearity i am writing the java files inside a package "toy" used here..as below....>>

*******************  files used *****************

***** remote interface *******

package toy;

import java.rmi.*;
import javax.ejb.*;
public interface Game extends EJBObject
 {
    public String getName()throws RemoteException;
      public int getSum(int x1,int x2) throws RemoteException;

}

********** home interface *********

package toy;

import java.rmi.*;
import javax.ejb.*;
import java.util.*;

public interface GameHome extends EJBHome
{

   public Game create()throws RemoteException,CreateException;

  }

******** bean **********

package toy;

import javax.ejb.CreateException;
import javax.ejb.SessionBean;
import javax.ejb.SessionContext;
import javax.naming.InitialContext;
import javax.sql.DataSource;
import javax.naming.NamingException;
import javax.ejb.EJBException;
import java.sql.*;

  public class GameBean implements SessionBean
  {
   
  public void ejbActivate() {System.out.println("Activate");  }
  public void ejbRemove() {  System.out.println("remove");}
  public void ejbPassivate() { System.out.println("<.....passivate....>"); }
  public void setSessionContext(SessionContext ctx) {    System.out.println("<....sessioncontext....>");    }
  public void ejbCreate () throws CreateException {  System.out.println("<.....create....>");    }
 
  public String getName()
  {
     System.out.println("<.....chk 1 .....>");
       String name="GAME";
      
      return name;
 }

 public int getSum(int x1,int x2)
 {
  int x;
  x=x1+x2;
  System.out.println("<.....chk 5 ...x..> "+x);
  return x;
}

}



**************** ejb-jar.xml **************

<?xml version="1.0"?>

<!DOCTYPE ejb-jar PUBLIC '-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 1.1//EN' 'http://java.sun.com/j2ee/dtds/ejb-jar_1_1.dtd'>

<ejb-jar>
 <enterprise-beans>
  <session>
  <ejb-name>Game</ejb-name>
  <home>toy.GameHome</home>
  <remote>toy.Game</remote>
  <ejb-class>toy.GameBean</ejb-class>
  <session-type>Stateless</session-type>
  <transaction-type>Container</transaction-type>
  </session>
 </enterprise-beans>
</ejb-jar>


**************  clent servlet  ***************


package toy;

import toy.Game;
import toy.GameHome;

import javax.ejb.*;
import javax.rmi.*;
import javax.rmi.PortableRemoteObject;
import javax.naming.InitialContext;
import javax.naming.Context;
import javax.naming.*;
import java.io.*;
import java.util.Properties;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class GameServ extends HttpServlet {

  public void init(ServletConfig config) throws ServletException  {
    super.init(config);
 
  }

  public void service(HttpServletRequest req, HttpServletResponse res)
       throws IOException
  {
 
    res.setContentType("text/html");
    PrintWriter out = res.getWriter();
     
       int ss=0;
       String name="";
       System.out.println("inside client : GameServ ");
       try
       {
          String url = "t3://localhost:7001";
         
        Properties h = new Properties();
          h.put(Context.INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLInitialContextFactory");
          h.put(Context.PROVIDER_URL, url);
          Context ctx = new InitialContext(h);
             
        Object ref = ctx.lookup("gum");
        System.out.println("inside client : objref-3 "+ref);
      
        System.out.println("....inside Zone...");

(**)        GameHome sh=(GameHome) PortableRemoteObject.narrow(ref,GameHome.class);
//here i am getting    >> ClassCastEXCEPTION<<

          System.out.println("inside client : sh-4 "+sh);
      
         Game sr =sh.create();
        System.out.println("inside client : sr-5 "+sr);
            
        name=sr.getName();
          System.out.println(" Client ...Got the name : "+name);
 
         ss = sr.getSum(1,7);
         System.out.println("Got the Sum :" + String.valueOf(ss));

      }
      catch(Exception e)
          {
              System.out.println(e);
            }

   
    out.println("<html><head>\n" +
                "<title>Check Servlet</title>\n" +
                "</head>\n" +
                "<body bgcolor=#ffffff> <font face=\"Comic Sans MS\" size+=4 color=red>" +
                "<br> <center><h1> name = "+name+"</h1></center>" +
            "<br> <center><h1> sum = "+ss+"</h1></center>" +
              "<center><h1>Game</h1></center>");
    out.println("</body></html>");
  }
}



************************** Exception I am getting  ****************************

inside the "toy.GameServ.java" i am getting    >> ClassCastEXCEPTION<< at line (**) as below

   " GameHome sh=(GameHome) PortableRemoteObject.narrow(ref,GameHome.class); "

I hope i have described my problem very well and i request you to give me solution so that my client application may call the bean.

********  Waiting for the response. *******

*******************************    END    ****************************************

 
0
Comment
Question by:sanjeev_1772
4 Comments
 
LVL 1

Accepted Solution

by:
naidubs earned 50 total points
ID: 7176721
using reflection try to get class name , so that u will come to know which class ur getting.
code is
Class cls = ref.getClass();
S.O.P("class name"+cls.getName());

uu need to verify the class path and add home&remote classes in client jar file.
0

Featured Post

ScreenConnect 6.0 Free Trial

Want empowering updates? You're in the right place! Discover new features in ScreenConnect 6.0, based on partner feedback, to keep you business operating smoothly and optimally (the way it should be). Explore all of the extras and enhancements for yourself!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
"Could not find or load main class" Java runtime error 74 1,001
activemq cluster 1 237
method inner class 6 82
how to pass values from bean to JSF page 4 98
-Xmx and -Xms are the two JVM options often used to tune JVM heap size.   Here are some common mistakes made when using them:   Assume BigApp is a java class file for the below examples. 1.         Missing m, M, g or G at the end …
Most of the developers using Tomcat find it easy to configure the datasource in Server.xml and use the JNDI name in the code to get the connection.  So the default connection pool using DBCP (or any other framework) is made available and the life go…
Two types of users will appreciate AOMEI Backupper Pro: 1 - Those with PCIe drives (and haven't found cloning software that works on them). 2 - Those who want a fast clone of their boot drive (no re-boots needed) and it can clone your drive wh…
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…

778 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question