Login codes using java database (validates with Microsoft Access File)

Question

hi all pro-programmer, can you show me the code to login with the username and password using java database. When the user enters the username and password in the login page then it will go to the requested page. may i know how to do it?

Answer 1

no one will give you complete code.
i'll lay out the pieces for you, though:
(1) start with a User object. give it username and password attributes.
(2) write a UserDAO interface with CRUD operations for a User object.
(3) write a UserDAOImpl for your Microsoft Access database
(4) write an AuthenticationService interface
(5) write an implementation of the AuthenicationService that works with the UserDAO to authorize a User.
Use a servlet to accept request from your login page and pass it off to the service. Voila.
PS - Here's skeleton to start with. UI, servlet, and controller are your responsibility:
package model;
public class User implements Serializable
    private String username;
    private String password;
    public User(String u, String p)
        this.username = u;
        this.password = p;
    public String getUsername() { return username; }
    public String getPassword() { return password; }
public interface UserDAO
    public User findByUsername(String username);
    public void saveOrUpdate(User user);
    public void delete(User user);
public class UserDAOImpl implements UserDAO
    private Connection connection;
    public UserDAOImpl(Connection connection)
        this.connection = connection;
    public User findByUsername(String username)
        String password = "";
        // logic for querying the database for a User
        return new User(username, password);
    public void saveOrUpdate(User user)
        // save or update a User
    public void delete(User user)
        // delete a User
public interface AuthenticationService
    public boolean isAuthorized(String username);
public class AuthenticationServiceImpl implements AuthenticationService
    private UserDAO userDAO;
    public AuthenticationServiceImpl()
        // Create a database connection here and the UserDAO, too.
    public boolean isAuthorized(String username)
        boolean isAuthorized = false;
        // Add logic to do the database query and decide if the username is authorized
        return isAuthorized;       
}