ClassCastException in JSP and EJB

[star111792]

helo all,

i am working with JSP and EJBs. i have written a simple code for verifying username and password of user by using session beans. my problem is that i m getting exception named "ClassCastException". Exception is as follows:


[exception]

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException
org.apache.jasper.servlet.JspServletWrapper.servic e(JspServletWrapper.java:370)
org.apache.jasper.servlet.JspServlet.serviceJspFil e(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspSe rvlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet .java:810)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doF ilter(ReplyHeaderFilter.java:81)

root cause

java.lang.ClassCastException
com.sun.corba.se.internal.javax.rmi.PortableRemote Object.narrow(PortableRemoteObject.java:293)
javax.rmi.PortableRemoteObject.narrow(PortableRemo teObject.java:134)
org.apache.jsp.Verify_jsp._jspService(org.apache.j sp.Verify_jsp:70)
org.apache.jasper.runtime.HttpJspBase.service(Http JspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet .java:810)
org.apache.jasper.servlet.JspServletWrapper.servic e(JspServletWrapper.java:322)
org.apache.jasper.servlet.JspServlet.serviceJspFil e(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspSe rvlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet .java:810)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doF ilter(ReplyHeaderFilter.java:81)

note The full stack trace of the root cause is available in the Apache Tomcat/5.5.9 logs.

[/exception]

i have change code a little bit which i m presenting for ur consideration:

 
VerifyUser.java
---------------
 
package hina.mahmood;
import javax.ejb.*;
import java.rmi.*;
 
public interface VerifyUser extends javax.ejb.EJBObject
{ 
public Boolean Verify(String user, String pswd) throws RemoteException;
}// end interface
*****************************
 
VerifyUserHome.java
-------------------
 
package hina.mahmood;
import javax.ejb.*;
import java.rmi.*;
import javax.ejb.EJBHome;
 
public interface VerifyUserHome extends javax.ejb.EJBHome
{
public VerifyUser create() throws RemoteException,CreateException;
}// end interface
*****************************
 
VerifyUserBean.java
--------------------
 
package hina.mahmood;
import javax.ejb.*;
import java.rmi.*;
import java.sql.*;
import javax.sql.*;
import javax.naming.*;
public class VerifyUserBean implements SessionBean
{
private SessionContext ctx;
public Boolean Verify(String user,String pswd) throws RemoteException
{
int flag=0;
Boolean bool=new Boolean("false");
try{
InitialContext ctx = new InitialContext();
DataSource ds =(DataSource)ctx.lookup("java:honie");
Connection con = ds.getConnection();
Statement stmt = con.createStatement();
String query="Select username,password from hina";
ResultSet rs=stmt.executeQuery(query);
 
while(rs.next())
{
if((rs.getString("username").equals(user))&&(rs.getString("password").equals(pswd)))
{
flag=1;
break;
}
}// end while
}// end try
 
catch(Exception e)
{System.out.println(e);}
 
if(flag==0)
{
bool=new Boolean("false");
return bool;
}
 
else
if(flag==1)
{
bool=new Boolean("true");
return bool;
}
 
return bool;
}// end method
 
public void ejbCreate() throws RemoteException,CreateException
{
}// end method
 
public void setSessionContext(SessionContext ctx)
{
this.ctx=ctx;
}
 
public void ejbPassivate()
{}
 
public void ejbActivate()
{}
 
public void ejbRemove()
{}
 
}// end class
*******************
 
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>
<session>
<display-name></display-name>
<ejb-name>VerifyUser</ejb-name>
<home>hina.mahmood.VerifyUserHome</home>
<remote>hina.mahmood.VerifyUser</remote>
<ejb-class>hina.mahmood.VerifyUserBean</ejb-class>
<session-type>Stateless</session-type>
<transaction-type>Container</transaction-type>
</session>
</enterprise-beans>
</ejb-jar>
******************************
 
Verify.jsp(page that calls this bean) 
------------------------------------
 
<%@ page import="java.rmi.*,javax.naming.Context,javax.naming.InitialContext,hina.mahmood.*"%>
 
<%
String username=request.getParameter("user");
String password=request.getParameter("pswd");
InitialContext cxt=new InitialContext();
Object obj=cxt.lookup("VerifyUser");
VerifyUserHome userHome=(VerifyUserHome)javax.rmi.PortableRemoteObject.narrow(obj,VerifyUserHome.class);
VerifyUser vs=userHome.create();
Boolean b=vs.Verify(username,password);
boolean bool=b.booleanValue();
if(bool)
response.sendRedirect("main.jsp");
else
response.sendRedirect("error.jsp");
 
%>
***********************
 
msaccess-ds.xml
---------------
 
<datasources>
<local-tx-datasource>
<jndi-name>honie</jndi-name>
<!-- format of URL is "jdbc:odbc:DSNNAME" -->
<connection-url>jdbc:odbc:honie</connection-url>
<driver-class>sun.jdbc.odbc.JdbcOdbcDriver</driver-class>
<user-name></user-name>
<password></password>
</local-tx-datasource>
 
</datasources>
********************* 
 
 

i dont know, what mistake i m doing now.:(
do i need to set any class path or anything else? currently i have set my class path to j2ee.jar, my other servlet taht do not involve ejbs are working perfectly.

my directory structue is as follows:

hm.war---> WEB-INF(folder) & Verify.jsp

WEBINF-->classes(folder) & web.xml
classes-->hina(folder)-->mahmood(folder)--> VerifyUser.class & VerifyUserBean.class & VerifyUserHome.class


my beans.jar contains:

beans.jar-->msaccess-ds.xml & META-INF & and package hina(folder)-->mahmood(folder)-->VerifyUser.class & VerifyUserBean.class & VerifyUserHome.class
META-INF-->ejb-jar.xml


plz plz plz help me. its really very important 4 me.
thanks

[prabha2277]

Dude you forgot put typecast for VerifyUser while getting object from Home.Please check the following highlighted JSP code where you did a mistake.



<%@ page import="java.rmi.*,javax.naming.Context,javax.nami ng.InitialContext,hina.mahmood.*"%>

<%
String username=request.getParameter("user");
String password=request.getParameter("pswd");
InitialContext cxt=new InitialContext();
Object obj=cxt.lookup("VerifyUser");
VerifyUserHome userHome=(VerifyUserHome)javax.rmi.PortableRemoteO bject.narrow(obj,VerifyUserHome.class);
VerifyUser vs=(VerifyUser )userHome.create();
Boolean b=vs.Verify(username,password);
boolean bool=b.booleanValue();
if(bool)
response.sendRedirect("main.jsp");
else
response.sendRedirect("error.jsp");

%>

[star111792]

1st of all, thanku so much 4 considering my question, bcoz no one was doing that. :(

what u have told above, i have tried that, but my problem is still there. :(
i think problem is not in this line of code, bcoz even if i remove this line and the lines under it, even then i m getting the same exception. what i guess is that, problem lies with the line just above the one that u have pointed out .i.e

VerifyUserHome userHome=(VerifyUserHome)javax.rmi.PortableRemoteO bject.narrow(obj,VerifyUserHome.class);

this line is creating all the problem(i think so) but i dont know how to get rid of this problem. if u can give me any further suggestions for fixing this error, plz do that. i'll be very grateful to u.

thanks.