What are the Interfaces need to create to implement Session Bean with Exmaple? | EJB Interview Questions

Session bean class (CartBean)
Home interface (CartHome)
Remote interface (Cart)

Session bean class (CartBean) :
public class CartBean implements SessionBean
{
String customerName;
String customerId;
Vector contents;
public void ejbCreate(String person)
throws CreateException {
if (person == null) {
throw new CreateException("Null person not allowed.");
}
else {
customerName = person;
}
customerId = "0";
contents = new Vector();
}
public void ejbCreate(String person, String id)
throws CreateException {
if (person == null) {
throw new CreateException("Null person not allowed.");
}
else {
customerName = person;
}

IdVerifier idChecker = new IdVerifier();
if (idChecker.validate(id)) {
customerId = id;
}
else {
throw new CreateException("Invalid id: "+ id);
}

contents = new Vector();
}

public void addBook(String title) {
contents.addElement(title);
}

public void removeBook(String title) throws BookException {

boolean result = contents.removeElement(title);
if (result == false) {
throw new BookException(title + "not in cart.");
}
}

public Vector getContents() {
return contents;
}

public CartBean() {}
public void ejbRemove() {}
public void ejbActivate() {}
public void ejbPassivate() {}
public void setSessionContext(SessionContext sc) {}

}


Home Interface:
public interface CartHome extends EJBHome {
Cart create(String person) throws
RemoteException, CreateException;
Cart create(String person, String id) throws
RemoteException, CreateException;
}

The signatures of the ejbCreate and create methods are similar, but differ in important ways. The rules for defining the signatures of the create methods of a home interface follow.

The number and types of arguments in a create method must match those of its corresponding ejb Create method.
The arguments and return type of the create method must be valid RMI types.
A create method returns the remote interface type of the enterprise bean. (But an ejbCreate method returns void.)
The throws clause of the create method must include the java.rmi.RemoteException and the javax.ejb.CreateException

Remote Interface :
public interface Cart extends EJBObject {
public void addBook(String title) throws RemoteException;
public void removeBook(String title) throws
BookException, RemoteException;
public Vector getContents() throws RemoteException;
}

The method definitions in a remote interface must follow these rules:
Each method in the remote interface must match a method implemented in the enterprise bean class.
The signatures of the methods in the remote interface must be identical to the signatures of the corresponding methods in the enterprise bean class.
The arguments and return values must be valid RMI types.
The throws clause must include the java.rmi.RemoteEx