Defining the RowMapper

As we are using the JDBC Template, we need a way to map the rows of data from a database to a Java object. This can be achieved by implementing a RowMapper interface. We will define mapper classes for all the three entities. For Country, the raw mapper class looks as follows:

public class CountryRowMapper implements RowMapper<Country>{

  public Country mapRow(ResultSet rs, int rowNum) 
                            throws SQLException {
    Country country = new Country();
    country.setCode(rs.getString("code"));
    country.setName(rs.getString("name"));
    country.setContinent(rs.getString("continent"));
    country.setRegion(rs.getString("region"));
    country.setSurfaceArea(rs.getDouble("surface_area"));
    country.setIndepYear(rs.getShort("indep_year"));
    country.setPopulation(rs.getLong("population"));
    country.setLifeExpectancy(rs.getDouble("life_expectancy"));
    country.setGnp(rs.getDouble("gnp"));
    country.setLocalName(rs.getString("local_name"));
    country.setGovernmentForm(rs.getString("government_form"));
    country.setHeadOfState(rs.getString("head_of_state"));
    country.setCode2(rs.getString("code2"));
    if ( Long.valueOf(rs.getLong("capital")) != null ) {
      City city = new City();
      city.setId(rs.getLong("capital"));
      city.setName(rs.getString("capital_name"));
      country.setCapital(city);
    }
    return country;
  }
}

Then we define the mapper class for City as follows:

public class CityRowMapper implements RowMapper<City>{
  public City mapRow(ResultSet rs, int rowNum) 
                    throws SQLException {
    City city = new City();
    city.setCountryCode(rs.getString("country_code"));
    city.setDistrict(rs.getString("district"));
    city.setId(rs.getLong("id"));
    city.setName(rs.getString("name"));
    city.setPopulation(rs.getLong("population"));
    return city;
  }
}

And finally, we define CountryLanguage as follows:

public class CountryLanguageRowMapper implements 
                       RowMapper<CountryLanguage> {
  public CountryLanguage mapRow(ResultSet rs, int rowNum) 
                                 throws SQLException {
    CountryLanguage countryLng = new CountryLanguage();
    countryLng.setCountryCode(rs.getString("countrycode"));
    countryLng.setIsOfficial(rs.getString("isofficial"));
    countryLng.setLanguage(rs.getString("language"));
    countryLng.setPercentage(rs.getDouble("percentage"));
    return countryLng;
  }
}