Class not Found Exception while running an EJB

Question

I have created and published a EJB in Oracle 8i (in a particular
schema) by running the deployejb tool supplied. The ejb was
published successfully. On running the client program I get an
error saying that the mybeans's HomeHelper class cannot be
found. This error occurs when there is a lookup to the home
interface of the bean. The exception thrown says Reasons are
unknown. On checking the objects of type 'JAVA CLASS' I found
that the homeHelper class object had been created automatically
be the deploy process. What is the reason for the class not
found exception and what can I do to correct it. ?
The code for the beans is as given below :
Home Interface
package mituser ;
import javax.ejb.*;
import java.rmi.RemoteException;
public interface MITUserHome extends EJBHome {
public MITUser create()
throws CreateException, RemoteException;
Remote Interface
package mituser ;
import javax.ejb.EJBObject;
import java.rmi.RemoteException;
public interface MITUser extends EJBObject {
public int validateUserName (String username)
throws java.sql.SQLException, RemoteException;
public int validatePassword (String username, String password)
throws java.sql.SQLException, RemoteException;
public String validateSearchAccess (String username, String
password)
throws java.sql.SQLException, RemoteException;
Bean
package mituserServer ;
import java.sql.*;
import java.rmi.RemoteException;
import javax.ejb.*;
public class MITUserBean implements SessionBean {
SessionContext ctx;
public void ejbCreate() throws CreateException,
RemoteException {
public void ejbActivate() {
public void ejbPassivate() {
public void ejbRemove() {
public void setSessionContext(SessionContext ctx) {
this.ctx = ctx;
public int validateUserName (String username) throws
SQLException, RemoteException
int count = 0 ;
Connection conn =
new oracle.jdbc.driver.OracleDriver().defaultConnection ();
PreparedStatement ps =
conn.prepareStatement ("select count(username) from
useraccountinfo where username = ?");
try {
ps.setString (1, username);
ResultSet rset = ps.executeQuery ();
if (!rset.next ())
throw new RemoteException ("no registered user with User
Name " + username);
count = rset.getShort(1) ;
return count ;
} finally {
ps.close();
public int validatePassword (String username, String password)
throws SQLException, RemoteException
int count = 0 ;
Connection conn =
new oracle.jdbc.driver.OracleDriver().defaultConnection ();
PreparedStatement ps =
conn.prepareStatement ("select count(username) from
useraccountinfo where username = ? and password = ?");
try {
ps.setString (1, username);
ps.setString(2, password);
ResultSet rset = ps.executeQuery ();
if (!rset.next ())
throw new RemoteException ("Invalid Password ");
count = rset.getShort(1) ;
return count ;
} finally {
ps.close();
public String validateSearchAccess (String username, String
password) throws SQLException, RemoteException
String searchaccess = "" ;
Connection conn =
new oracle.jdbc.driver.OracleDriver().defaultConnection ();
PreparedStatement ps =
conn.prepareStatement ("select searchprofileaccess from
useraccountinfo where username = ? and password = ?");
try {
ps.setString (1, username);
ps.setString(2, password);
ResultSet rset = ps.executeQuery ();
if (!rset.next ())
throw new RemoteException ("Access Denied for " +
username );
searchaccess = rset.getString(1) ;
return searchaccess ;
} finally {
ps.close();
Client program
import mituser.MITUser;
import mituser.MITUserHome;
import oracle.aurora.jndi.sess_iiop.ServiceCtx;
import javax.naming.Context;
import javax.naming.InitialContext;
import java.util.Hashtable;
public class Client {
public static void main (String [] args) throws Exception {
int count = 0 ;
String access = "" ;
if (args.length != 4) {
System.out.println("usage: Client serviceURL objectName
user password");
System.exit(1);
String serviceURL = args [0];
String objectName = args [1];
String user = args [2];
String password = args [3];
Hashtable env = new Hashtable();
env.put(Context.URL_PKG_PREFIXES, "oracle.aurora.jndi");
env.put(Context.SECURITY_PRINCIPAL, user);
env.put(Context.SECURITY_CREDENTIALS, password);
env.put(Context.SECURITY_AUTHENTICATION,
ServiceCtx.NON_SSL_LOGIN);
Context ic = new InitialContext(env);
MITUserHome home = (MITUserHome)ic.lookup (serviceURL +
objectName);
MITUser testBean = home.create ();
count = testBean.validateUserName("MITA");
if (count > 0 )
System.out.println ("Valid User");
else
System.out.println ("Invalid User");
count = testBean.validatePassword("MITA", "MITA");
if (count > 0 )
System.out.println ("Valid Password");
else
System.out.println ("Invalid Password");
access = testBean.validateSearchAccess("MITA", "MITA");
if ( access.equalsIgnoreCase("YES") )
System.out.println ("Search Access Available");
else
System.out.println ("Search Access Denied");
The Descriptor file
// MIT UserBean EJB deployment descriptor
SessionBean mituserServer.MITUserBean {
BeanHomeName = "test/mitUserJDBCBean";
RemoteInterfaceClassName = mituser.MITUser;
HomeInterfaceClassName = mituser.MITUserHome;
AllowedIdentities = {MIT};
SessionTimeout = 20;
StateManagementType = STATEFUL_SESSION;
RunAsMode = CLIENT_IDENTITY;
TransactionAttribute = TX_REQUIRED;
Batch File for deploying the ejb
@echo off
if (%ORACLE_HOME%)==() goto usage
if (%ORACLE_SERVICE%)==() goto usage
if (%JDK_CLASSPATH%)==() goto usage
@echo on
set CLASSPATH=.;%ORACLE_HOME%\lib\aurora_client.jar;%ORACLE_HOME%
\jdbc\lib\classes111.zip;%ORACLE_HOME%\sqlj\lib\translator.zip;%
ORACLE_HOME%\lib\vbjorb.jar;%ORACLE_HOME%\lib\vbjapp.jar;%
JDK_CLASSPATH%
javac -g mituser\MITUser.java
javac -g mituser\MITUserHome.java
javac -g mituserServer\MITUserBean.java
jar cf0 mituser.jar mituser\MITUser.class
mituser\MITUserHome.class mituserServer\MITUserBean.class
javac -g Client.java
call deployejb -republish -temp temp -u mit -p mit -s %
ORACLE_SERVICE% -descriptor mituser.ejb mituser.jar
@echo off
goto done
:usage
@echo -------------------------------------------------------
@echo Following are the requirements to run this script
@echo set ORACLE_HOME to installed Oracle home
@echo set ORACLE_SERVICE to the CORBA service name of
your databae
@echo for example sess_iiop://localhost:2481:ORCL
@echo set JDK_CLASSPATH to the full path of your JDK
classes.zip
@echo -------------------------------------------------------
:done
Batch file for running the cleint program
@echo off
if (%ORACLE_HOME%)==() goto usage
if (%ORACLE_SERVICE%)==() goto usage
if (%JDK_CLASSPATH%)==() goto usage
@echo on
set CLASSPATH=.;%ORACLE_HOME%\lib\aurora_client.jar;%ORACLE_HOME%
\jdbc\lib\classes111.zip;%ORACLE_HOME%\sqlj\lib\translator.zip;%
ORACLE_HOME%\lib\vbjorb.jar;%ORACLE_HOME%\lib\vbjapp.jar;%
JDK_CLASSPATH%;server_generated.jar
java Client %ORACLE_SERVICE% /test/mitUserJDBCBean mit mit
@echo off
goto done
:usage
@echo -------------------------------------------------------
@echo Following are the requirements to run this script
@echo set ORACLE_HOME to installed Oracle home
@echo set ORACLE_SERVICE to the CORBA service name of
your databae
@echo for example sess_iiop://localhost:2481:ORCL
@echo set JDK_CLASSPATH to the full path of your JDK
classes.zip
@echo -------------------------------------------------------
:done
I know this is not strictly to do with JDBC but there appears to
be no discussion forum for EJB
Hoping for a response soon as it us very URGENT
Thanks
Mita
null

Answer 1

I have created and published a EJB in Oracle 8i (in a particular
schema) by running the deployejb tool supplied. The ejb was
published successfully. On running the client program I get an
error saying that the mybeans's HomeHelper class cannot be
found. This error occurs when there is a lookup to the home
interface of the bean. The exception thrown says Reasons are
unknown. On checking the objects of type 'JAVA CLASS' I found
that the homeHelper class object had been created automatically
be the deploy process. What is the reason for the class not
found exception and what can I do to correct it. ?
The code for the beans is as given below :
Home Interface
package mituser ;
import javax.ejb.*;
import java.rmi.RemoteException;
public interface MITUserHome extends EJBHome {
public MITUser create()
throws CreateException, RemoteException;
Remote Interface
package mituser ;
import javax.ejb.EJBObject;
import java.rmi.RemoteException;
public interface MITUser extends EJBObject {
public int validateUserName (String username)
throws java.sql.SQLException, RemoteException;
public int validatePassword (String username, String password)
throws java.sql.SQLException, RemoteException;
public String validateSearchAccess (String username, String
password)
throws java.sql.SQLException, RemoteException;
Bean
package mituserServer ;
import java.sql.*;
import java.rmi.RemoteException;
import javax.ejb.*;
public class MITUserBean implements SessionBean {
SessionContext ctx;
public void ejbCreate() throws CreateException,
RemoteException {
public void ejbActivate() {
public void ejbPassivate() {
public void ejbRemove() {
public void setSessionContext(SessionContext ctx) {
this.ctx = ctx;
public int validateUserName (String username) throws
SQLException, RemoteException
int count = 0 ;
Connection conn =
new oracle.jdbc.driver.OracleDriver().defaultConnection ();
PreparedStatement ps =
conn.prepareStatement ("select count(username) from
useraccountinfo where username = ?");
try {
ps.setString (1, username);
ResultSet rset = ps.executeQuery ();
if (!rset.next ())
throw new RemoteException ("no registered user with User
Name " + username);
count = rset.getShort(1) ;
return count ;
} finally {
ps.close();
public int validatePassword (String username, String password)
throws SQLException, RemoteException
int count = 0 ;
Connection conn =
new oracle.jdbc.driver.OracleDriver().defaultConnection ();
PreparedStatement ps =
conn.prepareStatement ("select count(username) from
useraccountinfo where username = ? and password = ?");
try {
ps.setString (1, username);
ps.setString(2, password);
ResultSet rset = ps.executeQuery ();
if (!rset.next ())
throw new RemoteException ("Invalid Password ");
count = rset.getShort(1) ;
return count ;
} finally {
ps.close();
public String validateSearchAccess (String username, String
password) throws SQLException, RemoteException
String searchaccess = "" ;
Connection conn =
new oracle.jdbc.driver.OracleDriver().defaultConnection ();
PreparedStatement ps =
conn.prepareStatement ("select searchprofileaccess from
useraccountinfo where username = ? and password = ?");
try {
ps.setString (1, username);
ps.setString(2, password);
ResultSet rset = ps.executeQuery ();
if (!rset.next ())
throw new RemoteException ("Access Denied for " +
username );
searchaccess = rset.getString(1) ;
return searchaccess ;
} finally {
ps.close();
Client program
import mituser.MITUser;
import mituser.MITUserHome;
import oracle.aurora.jndi.sess_iiop.ServiceCtx;
import javax.naming.Context;
import javax.naming.InitialContext;
import java.util.Hashtable;
public class Client {
public static void main (String [] args) throws Exception {
int count = 0 ;
String access = "" ;
if (args.length != 4) {
System.out.println("usage: Client serviceURL objectName
user password");
System.exit(1);
String serviceURL = args [0];
String objectName = args [1];
String user = args [2];
String password = args [3];
Hashtable env = new Hashtable();
env.put(Context.URL_PKG_PREFIXES, "oracle.aurora.jndi");
env.put(Context.SECURITY_PRINCIPAL, user);
env.put(Context.SECURITY_CREDENTIALS, password);
env.put(Context.SECURITY_AUTHENTICATION,
ServiceCtx.NON_SSL_LOGIN);
Context ic = new InitialContext(env);
MITUserHome home = (MITUserHome)ic.lookup (serviceURL +
objectName);
MITUser testBean = home.create ();
count = testBean.validateUserName("MITA");
if (count > 0 )
System.out.println ("Valid User");
else
System.out.println ("Invalid User");
count = testBean.validatePassword("MITA", "MITA");
if (count > 0 )
System.out.println ("Valid Password");
else
System.out.println ("Invalid Password");
access = testBean.validateSearchAccess("MITA", "MITA");
if ( access.equalsIgnoreCase("YES") )
System.out.println ("Search Access Available");
else
System.out.println ("Search Access Denied");
The Descriptor file
// MIT UserBean EJB deployment descriptor
SessionBean mituserServer.MITUserBean {
BeanHomeName = "test/mitUserJDBCBean";
RemoteInterfaceClassName = mituser.MITUser;
HomeInterfaceClassName = mituser.MITUserHome;
AllowedIdentities = {MIT};
SessionTimeout = 20;
StateManagementType = STATEFUL_SESSION;
RunAsMode = CLIENT_IDENTITY;
TransactionAttribute = TX_REQUIRED;
Batch File for deploying the ejb
@echo off
if (%ORACLE_HOME%)==() goto usage
if (%ORACLE_SERVICE%)==() goto usage
if (%JDK_CLASSPATH%)==() goto usage
@echo on
set CLASSPATH=.;%ORACLE_HOME%\lib\aurora_client.jar;%ORACLE_HOME%
\jdbc\lib\classes111.zip;%ORACLE_HOME%\sqlj\lib\translator.zip;%
ORACLE_HOME%\lib\vbjorb.jar;%ORACLE_HOME%\lib\vbjapp.jar;%
JDK_CLASSPATH%
javac -g mituser\MITUser.java
javac -g mituser\MITUserHome.java
javac -g mituserServer\MITUserBean.java
jar cf0 mituser.jar mituser\MITUser.class
mituser\MITUserHome.class mituserServer\MITUserBean.class
javac -g Client.java
call deployejb -republish -temp temp -u mit -p mit -s %
ORACLE_SERVICE% -descriptor mituser.ejb mituser.jar
@echo off
goto done
:usage
@echo -------------------------------------------------------
@echo Following are the requirements to run this script
@echo set ORACLE_HOME to installed Oracle home
@echo set ORACLE_SERVICE to the CORBA service name of
your databae
@echo for example sess_iiop://localhost:2481:ORCL
@echo set JDK_CLASSPATH to the full path of your JDK
classes.zip
@echo -------------------------------------------------------
:done
Batch file for running the cleint program
@echo off
if (%ORACLE_HOME%)==() goto usage
if (%ORACLE_SERVICE%)==() goto usage
if (%JDK_CLASSPATH%)==() goto usage
@echo on
set CLASSPATH=.;%ORACLE_HOME%\lib\aurora_client.jar;%ORACLE_HOME%
\jdbc\lib\classes111.zip;%ORACLE_HOME%\sqlj\lib\translator.zip;%
ORACLE_HOME%\lib\vbjorb.jar;%ORACLE_HOME%\lib\vbjapp.jar;%
JDK_CLASSPATH%;server_generated.jar
java Client %ORACLE_SERVICE% /test/mitUserJDBCBean mit mit
@echo off
goto done
:usage
@echo -------------------------------------------------------
@echo Following are the requirements to run this script
@echo set ORACLE_HOME to installed Oracle home
@echo set ORACLE_SERVICE to the CORBA service name of
your databae
@echo for example sess_iiop://localhost:2481:ORCL
@echo set JDK_CLASSPATH to the full path of your JDK
classes.zip
@echo -------------------------------------------------------
:done
I know this is not strictly to do with JDBC but there appears to
be no discussion forum for EJB
Hoping for a response soon as it us very URGENT
Thanks
Mita
null