I am aware of factory and abstract factory methods, but I want to create a DAO factory pattern in Java.
- I want to know its importance.
- Its usage
I have checked this link but it is difficult for me to understand.
Can anyone explain it with the help of an example?
Edit: Here is an example of DAO pattern as I understood it:
public interface UserDAO {
public void insert(User user);
public void update(User user);
public void delete(int userId);
}
Implementation:
public class UserDAOImpl implements UserDAO {
@Override
public void delete(int userId) {
// delete user from user table
}
@Override
public User[] findAll() {
// get a list of all users from user table
return null;
}
@Override
public User findByKey(int userId) {
// get a user information if we supply unique userid
return null;
}
@Override
public void insert(User user) {
// insert user into user table
}
@Override
public void update(User user) {
// update user information in user table
}
}
Factory:
public class UserDAOFactory {
public static UserDAO getUserDAO(String type) {
if (type.equalsIgnoreCase("jdbc")) {
return new UserDAOImpl();
} else {
return new UserDAOImpl();
}
}
}
Client side code:
User user=new User();
user.setName("Jinoy P George");
user.setDesignation("Programmer");
user.setAge(35);
//get a reference to UserDAO object
UserDAO userDAO=UserDAOFactory.getUserDAO("jdbc");
//call insert method by passing user object
userDAO.insert(user);
Is this dao pattern correct?
Where should I open connection and close it?
question from:
https://stackoverflow.com/questions/6401543/what-is-dao-factory-pattern 与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…