Given:
What two changes should you make to apply the DAO pattern to this class?
A.
Make the Customer class abstract.
B.
Make the customer class an interface.
C.
Move the add, delete, find, and update methods into their own implementation class.
D.
Create an interface that defines the signatures of the add, delete, find, and update methods.
E.
Make the add, delete, and find, and update methods private for encapsulation.
F.
Make the getName and getID methods private for encapsulation.
Explanation:
C:The methods related directly to the entity Customer is moved to a new class.
D: Example (here Customer is the main entity):
public class Customer {
private final String id;
private String contactName;
private String phone;
public void setId(String id) { this.id = id; }
102
public String getId() { return this.id; }
public void setContactName(String cn) { this.contactName = cn;} public String getContactName() {
return
this.contactName; } public void setPhone(String phone) { this.phone = phone; } public String
getPhone()
{ return this.phone; }
}
public interface CustomerDAO {
public void addCustomer(Customer c) throws DataAccessException; public Customer
getCustomer(String id)throws DataAccessException; public List getCustomers() throws
DataAccessException; public void
removeCustomer(String id) throws DataAccessException; public void modifyCustomer(Customer
c) throws
DataAccessException; }
Note: DAO Design Pattern
*Abstracts and encapsulates all access to a data source *Manages the connection to the data
source to obtainand store data *Makes the code independent of the data sources and data
vendors (e.g. plain-text, xml, LDAP, MySQL, Oracle, DB2)
B
C