設計高效的Java DAO層需要考慮多個方面,包括代碼結構、性能優(yōu)化、可維護性和可擴展性。以下是一些關鍵的最佳實踐:
addBatch()
和executeBatch()
方法。以下是一個簡單的Spring Boot項目中DAO層的示例:
// UserDao接口
public interface UserDao {
List<User> findAllUsers();
User findUserById(Long id);
void insertUser(User user);
void updateUser(User user);
void deleteUser(Long id);
}
// UserDaoImpl實現(xiàn)類
@Repository
public class UserDaoImpl implements UserDao {
@Autowired
private JdbcTemplate jdbcTemplate;
@Override
public List<User> findAllUsers() {
String sql = "SELECT * FROM users";
return jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(User.class));
}
@Override
public User findUserById(Long id) {
String sql = "SELECT * FROM users WHERE id = ?";
return jdbcTemplate.queryForObject(sql, new BeanPropertyRowMapper<>(User.class), id);
}
@Override
public void insertUser(User user) {
String sql = "INSERT INTO users (name, email) VALUES (?, ?)";
jdbcTemplate.update(sql, user.getName(), user.getEmail());
}
@Override
public void updateUser(User user) {
String sql = "UPDATE users SET name = ?, email = ? WHERE id = ?";
jdbcTemplate.update(sql, user.getName(), user.getEmail(), user.getId());
}
@Override
public void deleteUser(Long id) {
String sql = "DELETE FROM users WHERE id = ?";
jdbcTemplate.update(sql, id);
}
}
通過遵循上述最佳實踐,可以設計出高效、可維護和可擴展的Java DAO層。