Models

public class User {
	private int id;
	private String email;
	private String password;
	private String role;
	
	public User(String email, String password, String role) {
		super();
		this.email = email;
		this.password = password;
		this.role = role;
	}
	public User(int id, String email, String password, String role) {
		super();
		this.id = id;
		this.email = email;
		this.password = password;
		this.role = role;
	}
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getRole() {
		return role;
	}
	public void setRole(String role) {
		this.role = role;
	}
	
	public Order order() {
		return Database.getInstance().getOrderDao().find(id);
	}
        
        public List<Order> getOrders() {
        return DatabaseDao.getInstance().getOrderDao().findByUser(id);
    }
	

}

Interface DAO

public interface UserDAO {

    public boolean insert(User user);

    public boolean update(User user);

    public boolean delete(int email);

    public User find(int id);

    public List<User> findAll();

    public User find(String email, String password);

    public User find(String email);
}

Implements

public class UserImpl implements UserDAO {

    Connection con = MySQLDriver.getInstance().getConnection();

    @Override
    public boolean insert(User user) {
        // TODO Auto-generated method stub
        String sql = "INSERT INTO USERS(ID, EMAIL, PASSWORD, ROLE) VALUES(null, ?, ?, ?)";
        try {
            PreparedStatement stmt = con.prepareStatement(sql);
            stmt.setString(1, user.getEmail());
            stmt.setString(2, user.getPassword());
            stmt.setString(3, user.getRole());

            stmt.execute();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return false;
    }

    @Override
    public boolean update(User user) {
        // TODO Auto-generated method stub
        String sql = "UPDATE USERS SET email = ? ,password = ?, role = ? WHERE id = ?";
        try {
            PreparedStatement stmt = con.prepareStatement(sql);
            stmt.setString(1, user.getEmail());
            stmt.setString(2, user.getPassword());
            stmt.setString(3, user.getRole());
            stmt.setInt(4, user.getId());
            return stmt.execute();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return false;
    }

    @Override
    public boolean delete(int id) {
        // TODO Auto-generated method stub
        String sql = "DELETE FROM USERS WHERE id = ?";
        try {
            PreparedStatement stmt = con.prepareStatement(sql);
            stmt.setInt(1, id);

            return stmt.execute();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return false;
    }

    @Override
    public User find(int id) {
        String sql = "SELECT * FROM USERS WHERE ID = ?";
        try {
            PreparedStatement stmt = con.prepareStatement(sql);
            stmt.setInt(1, id);

            ResultSet rs = stmt.executeQuery();
            while (rs.next()) {
                String email = rs.getString("email");
                String password = rs.getString("password");
                String role = rs.getString("role");

                return new User(id, email, password, role);
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

    @Override
    public List<User> findAll() {
        List<User> users = new ArrayList<>();
        String sql = "SELECT * FROM Users WHERE ID > ? ";
        try {
            PreparedStatement stmt = con.prepareStatement(sql);
            stmt.setInt(1, 0);
            ResultSet rs = stmt.executeQuery();
            while (rs.next()) {
                int id = rs.getInt("id");
                String email = rs.getString("email");
                String password = rs.getString("password");
                String role = rs.getString("role");

                users.add(new User(id, email, password, role));
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return users;
    }

    @Override
    public User find(String email, String password) {
        String sql = "SELECT * FROM USERS WHERE EMAIL = ? AND PASSWORD = ?";
        try {
            PreparedStatement stmt = con.prepareStatement(sql);
            stmt.setString(1, email);
            stmt.setString(2, password);

            ResultSet rs = stmt.executeQuery();
            while (rs.next()) {
                int id = rs.getInt("id");
                String role = rs.getString("role");
                return new User(id, email, password, role);
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

    @Override
    public User find(String email) {
        String sql = "SELECT * FROM USERS WHERE EMAIL = ?";
        try {
            PreparedStatement stmt = con.prepareStatement(sql);
            stmt.setString(1, email);
            ResultSet rs = stmt.executeQuery();
            while (rs.next()) {
                int id = rs.getInt("id");
                String password = rs.getString("password");
                String role = rs.getString("role");
                return new User(id, email, password, role);
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

}