Bean meanged persistence

Question

I am trying to execute EJB example on bean managed persistence from the book
It give me this error:
Error unmarshalling return; nested exception is:
java.io.invalidclassException:c8e.z.a;class invlaid for serailization
I tried examples from the net but same error shows up
please help me regarding this

Answer 1

Hey it returns the string object ...
here is snippet of my EJB and Client code........
import java.sql.*;
import javax.sql.*;
import java.util.*;
import javax.ejb.*;
import javax.naming.*;
public class AccountEJB implements EntityBean {
private String id;
private String firstName;
private String lastName;
private double balance;
private EntityContext context;
private Connection con;
private String dbName = "java:comp/env/jdbc/account";
public void debit(double amount)
throws InsufficientBalanceException {
if (balance - amount < 0) {
throw new InsufficientBalanceException();
balance -= amount;
public void credit(double amount) {
balance += amount;
public String getFirstName() {
return firstName;
public String getLastName() {
return lastName;
public double getBalance() {
return balance;
public String ejbCreate(String id, String firstName,
String lastName, double balance)
throws CreateException {
if (balance < 0.00) {
throw new CreateException
("A negative initial balance is not allowed.");
try {
insertRow(id, firstName, lastName, balance);
} catch (Exception ex) {
throw new EJBException("ejbCreate: " +
ex.getMessage());
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.balance = balance;
return id;
client code::::::::::::
public class AccountClient {
public static void main(String[] args) {
try {
Context initial = new InitialContext();
Object objref = initial.lookup("MyAccount");
AccountHome home =
(AccountHome)PortableRemoteObject.narrow(objref,
AccountHome.class);
Account duke = home.create("123", "Duke", "Earl", 0.00);
duke.credit(88.50);