@Override
public Ingredient findOne(String id) {
	Connection connection = null;
	PreparedStatement statement = null;
	ResultSet resultSet = null;
	try {
		connection = dataSource.getConnection();
		statement = connection.prepareStatement(
		"select id, name, type from Ingredient");
		statement.setString(1, id);
		resultSet = statement.executeQuery();
		Ingredient ingredient = null;
		if(resultSet.next()) {
			ingredient = new Ingredient(
			resultSet.getString("id"),
			resultSet.getString("name"),
			Ingredient.Type.valueOf(resultSet.getString("type")));
		}
		return ingredient;
	} catch (SQLException e) {
		// ??? What should be done here ???
	} finally {
		if (resultSet != null) {
			try {
				resultSet.close();
			} catch (SQLException e) {}
		}
		if (statement != null) {
			try {
				statement.close();
			} catch (SQLException e) {}
		}

		if (connection != null) {
			try {
				connection.close();
			} catch (SQLException e) {}
		}
	}
	return null;
}

private JdbcTemplate jdbc;

@Override
public Ingredient findOne(String id) {
	return jdbc.queryForObject(
		"select id, name, type from Ingredient where id=?", this::mapRowToIngredient, id);
}
private Ingredient mapRowToIngredient(ResultSet rs, int rowNum)
	throws SQLException {
		return new Ingredient(
			rs.getString("id"),
			rs.getString("name"),
			Ingredient.Type.valueOf(rs.getString("type"))
		);
}

import tacos.Ingredient;
public interface IngredientRepository {
	Iterable findAll();
	Ingredient findOne(String id);
	Ingredient save(Ingredient ingredient);
}

// ---------------------

import tacos.Ingredient;

@Repository
public class JdbcIngredientRepository implements IngredientRepository {
	private JdbcTemplate jdbc;

	@Autowired
	public JdbcIngredientRepository(JdbcTemplate jdbc) {
		this.jdbc = jdbc;
	}

	@Override
	public Iterable findAll() {
		return jdbc.query("select id, name, type from Ingredient", this::mapRowToIngredient);
	}
	@Override
	public Ingredient findOne(String id) {
		return jdbc.queryForObject(
			"select id, name, type from Ingredient where id=?",	this::mapRowToIngredient, id);
	}
	
	@Override
	public Ingredient save(Ingredient ingredient) {
		jdbc.update(
			"insert into Ingredient (id, name, type) values (?, ?, ?)",
			ingredient.getId(),
			ingredient.getName(),
			ingredient.getType().toString());
		return ingredient;
	}	
	
	private Ingredient mapRowToIngredient(ResultSet rs, int rowNum)
		throws SQLException {
			return new Ingredient(
				rs.getString("id"),
				rs.getString("name"),
				Ingredient.Type.valueOf(rs.getString("type"))
			);
	}	

}

import java.sql.Timestamp;
import java.sql.Types;
import java.util.Arrays;
import java.util.Date;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.PreparedStatementCreator;
import org.springframework.jdbc.core.PreparedStatementCreatorFactory;
import org.springframework.jdbc.support.GeneratedKeyHolder;
import org.springframework.jdbc.support.KeyHolder;
import org.springframework.stereotype.Repository;
import tacos.Ingredient;
import tacos.Taco;

@Repository
public class JdbcTacoRepository implements TacoRepository {
	private JdbcTemplate jdbc;
	public JdbcTacoRepository(JdbcTemplate jdbc) {
		this.jdbc = jdbc;
	}
	@Override
	public Taco save(Taco taco) {
		long tacoId = saveTacoInfo(taco);
		taco.setId(tacoId);
		for (Ingredient ingredient : taco.getIngredients()) {
			saveIngredientToTaco(ingredient, tacoId);
		}
		return taco;
	}
	private long saveTacoInfo(Taco taco) {
		taco.setCreatedAt(new Date());
		PreparedStatementCreator psc = new PreparedStatementCreatorFactory(
			"insert into Taco (name, createdAt) values (?, ?)", Types.VARCHAR, Types.TIMESTAMP
			).newPreparedStatementCreator(
				Arrays.asList(
				taco.getName(),
				new Timestamp(taco.getCreatedAt().getTime()))
			);
		KeyHolder keyHolder = new GeneratedKeyHolder();
		jdbc.update(psc, keyHolder);
		return keyHolder.getKey().longValue();
	}
	private void saveIngredientToTaco( Ingredient ingredient, long tacoId) {
		jdbc.update(
			"insert into Taco_Ingredients (taco, ingredient) " +
			"values (?, ?)",
			tacoId, ingredient.getId());
	}
}