package rewards.internal.restaurant;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import org.springframework.dao.EmptyResultDataAccessException;
import common.money.Percentage;
/**
* Loads restaurants from a data source using the JDBC API.
*/
public class JdbcRestaurantRepository implements RestaurantRepository {
private DataSource dataSource;
public Restaurant findByMerchantNumber(String merchantNumber) {
String sql = "select MERCHANT_NUMBER, NAME, BENEFIT_PERCENTAGE from T_RESTAURANT where MERCHANT_NUMBER = ?";
Restaurant restaurant = null;
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
conn = dataSource.getConnection();
ps = conn.prepareStatement(sql);
ps.setString(1, merchantNumber);
rs = ps.executeQuery();
advanceToNextRow(rs);
restaurant = mapRestaurant(rs);
} catch (SQLException e) {
throw new RuntimeException("SQL exception occurred finding by merchant number", e);
} finally {
if (rs != null) {
try {
// Close to prevent database cursor exhaustion
rs.close();
} catch (SQLException ex) {
}
}
if (ps != null) {
try {
// Close to prevent database cursor exhaustion
ps.close();
} catch (SQLException ex) {
}
}
if (conn != null) {
try {
// Close to prevent database connection exhaustion
conn.close();
} catch (SQLException ex) {
}
}
}
return restaurant;
}
/**
* Maps a row returned from a query of T_RESTAURANT to a Restaurant object.
* @param rs the result set with its cursor positioned at the current row
*/
private Restaurant mapRestaurant(ResultSet rs) throws SQLException {
// get the row column data
String name = rs.getString("NAME");
String number = rs.getString("MERCHANT_NUMBER");
Percentage benefitPercentage = Percentage.valueOf(rs.getString("BENEFIT_PERCENTAGE"));
// map to the object
Restaurant restaurant = new Restaurant(number, name);
restaurant.setBenefitPercentage(benefitPercentage);
return restaurant;
}
/**
* Advances a ResultSet to the next row and throws an exception if there are no rows.
* @param rs the ResultSet to advance
* @throws EmptyResultDataAccessException if there is no next row
* @throws SQLException
*/
private void advanceToNextRow(ResultSet rs) throws EmptyResultDataAccessException, SQLException {
if (!rs.next()) {
throw new EmptyResultDataAccessException(1);
}
}
}