Example 8.12 Value Object Factory Strategy - Value Objects and 
Interfaces

public interface Contact 
  extends java.io.Serializable {
  public String getFirstName();
  public String getLastName();
  public String getContactAddress();
  public void setFirstName(String firstName);
  public void setLastName(String lastName);
  public void setContactAddress(String address);
}

public class ContactVO implements Contact {
  // member attributes
  public String firstName;
  public String lastName;
  public String contactAddress;

  // implement get and set methods per the 
  // Contact interface here. 
  ...
        }
public interface Customer 
  extends java.io.Serializable {
  public String getCustomerName();
  public String getCustomerAddress();
  public void setCustomerName(String customerName);
  public void setCustomerAddress(String 
      customerAddress);
}

public class CustomerVO implements Customer {
  public String customerName;
  public String customerAddress;

  // implement get and set methods per the 
  // Customer interface here.
  ...
}

public class CustomerContactVO implements Customer, 
  Contact {
  public String firstName;
  public String lastName;
  public String contactAddress;
  public String customerName;
  public String customerAddress;

  // implement get and set methods per the 
  // Customer and Contact interfaces here.
  ...
}