SpringMvc DAO接口和DAO实现的注释

Question

我想知道我是否正确地注释这些类,因为我是注释的新手:

Country.java

@Component
public class Country {

private int countryId;
private String countryName;
private String countryCode;

/**
 * No args constructor
 */
public Country() {
}

/**
 * @param countryId
 * @param countryName
 * @param countryCode
 */
public Country(int countryId, String countryName, String countryCode) {
    this.countryId = countryId;
    this.countryName = countryName;
    this.countryCode = countryCode;
}
    //getters and setters   

}

CountryDAO.java

@Repository
public interface CountryDAO {

    public List<Country> getCountryList();

    public void saveCountry(Country country);

    public void updateCountry(Country country);
}

JdbcCountryDAO.java

@Component
public class JdbcCountryDAO extends JdbcDaoSupport implements CountryDAO{

    private final Logger logger = Logger.getLogger(getClass());

    @Autowired
    public List<Country> getCountryList() {
        int countryId = 6;
        String countryCode = "AI";
        logger.debug("In getCountryList()");
        String sql = "SELECT * FROM TBLCOUNTRY WHERE countryId = ? AND countryCode = ?";
        logger.debug("Executing getCountryList String "+sql);

        Object[] parameters = new Object[] {countryId, countryCode};

        logger.info(sql);

        //List<Country> countryList = getJdbcTemplate().query(sql,new CountryMapper());
        List<Country> countryList = getJdbcTemplate().query(sql, parameters,new CountryMapper());
        return countryList;
    }

CountryManagerIFace.java

@Repository
public interface CountryManagerIFace extends Serializable{

    public void saveCountry(Country country);

    public List<Country> getCountries();
}

CountryManager.java

@Component
public class CountryManager implements CountryManagerIFace{

    @Autowired
    private CountryDAO countryDao;

    public void saveCountry(Country country) {
        countryDao.saveCountry(country);

    }

    public List<Country> getCountries() {
        return countryDao.getCountryList();
    }


    public void setCountryDao(CountryDAO countryDao){

        this.countryDao = countryDao;   

    }
}

Answer 1

这个答案应该清楚一点:Spring中的@ Component,@ Repository和@Service注释有什么区别？

你应该知道的其他事情:

• 您的实体和接口不需要任何注释.实际上,@ Component和其他派生注释只是意味着你正在动态声明一个Spring bean.例如,

  @Component
  public class MyComponent { ... }
  

  默认情况下,会在Spring的上下文中添加一个名为"myComponent"的bean.Spring bean默认是单例,表示真实的实例化对象.
  因此,将实体或接口声明为Spring bean是没有意义的.

• 管理器在语义上与服务相同,因此您应该使用@Service注释它们.

以下是您的代码应该如何:

// No annotation
public class Country {

和

// No annotation
public interface CountryDAO {

和

@Repository
public class JdbcCountryDAO extends JdbcDaoSupport implements CountryDAO {

和

// No annotation
public interface CountryManagerIFace extends Serializable{

和

@Service
public class CountryManager implements CountryManagerIFace{

    @Autowired
    private CountryDAO countryDao;

注意:我很少在代码中使用@Component,因为@Controller(表示层),@ Service(服务层)和@Repository(dao层)覆盖了我的主要Spring bean需求.