properties
db.url=jdbc:mysql://localhost:3306/mydatabase
db.username=root
db.password=123456
public interface UserDao {
void insert(User user);
void update(User user);
void delete(int userId);
User getById(int userId);
List<User> getAll();
}
public class UserDaoImpl implements UserDao {
@Override
public void insert(User user) {
}
@Override
public void update(User user) {
}
@Override
public void delete(int userId) {
}
@Override
public User getById(int userId) {
return null;
}
@Override
public List<User> getAll() {
return null;
}
}
@Override
public User getById(int userId) {
Connection conn = null;
PreparedStatement stmt = null;
ResultSet rs = null;
User user = null;
try {
conn = ConnectionPool.getConnection();
String sql = "SELECT * FROM users WHERE id = ?";
stmt = conn.prepareStatement(sql);
stmt.setInt(1, userId);
rs = stmt.executeQuery();
if (rs.next()) {
user = new User();
user.setId(rs.getInt("id"));
user.setName(rs.getString("name"));
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
}
return user;
}
public class UserService {
private UserDao userDao;
public UserService(UserDao userDao) {
this.userDao = userDao;
}
public void createUser(User user) {
userDao.insert(user);
}
public void updateUser(User user) {
userDao.update(user);
}
public void deleteUser(int userId) {
userDao.delete(userId);
}
}
