我的问题是:您的服务层是否与您使用的技术绑定?
例如,如果您使用休眠,则将一些仅作为休眠功能的 hql 查询或条件查询放入服务层,或者您只需调用 DAO(并且 dao 具有休眠实现,可能还有 jdbc 实现等)?
我在为我的软件构建有效的分层架构时遇到了一些麻烦。
编辑 这是一项简单的服务……我认为这是一项服务……不受我使用的技术的约束(休眠)
@Repository
public class PersonHibernateDAO implements PersonDAO {
@Autowired
SessionFactory sessionFactory;
... dao crud operations(implementation of PersonDAO interface) using sessionfactory ...
//and some hibernate features methods
public Person findByCriteria(Criterion criterion){
// code
}
}
@Service
public class PersonService {
@Autowired
private PersonDAO personDao;
@Autowired
private AccessDAO accessDao;
@Transactional
public boolean hasPermission(String username, String accessCode){
Person p=personDao.findByUsername(username);
Access a=accessDao.findByCode(accessCode);
... etc ...
}
}
这是一个使用 Dao 实现的服务
@Service
public class PersonService {
@Autowired
private PersonDAO personDao;
@Autowired
private AccessDAO accessDao;
@Transactional
public boolean hasPermission(String username, String password){
Person p=((PersonHibernateDao)personDao).findByCriteria(Restrictions.eq("username", username);
... etc ...
}
}
这两种方法哪一种是正确的?
编辑2
所以,总结一下我的理解:
// BASE DAO INTERFACE
public interface DAOInterface<EntityClass, IDType extends Serializable> {
EntityClass get(IDType id);
EntityClass findById(IDType id);
EntityClass save(EntityClass entity);
EntityClass update(EntityClass entity);
void delete(EntityClass entity);
}
// AN HIBERNATE IMPLEMENTATION
public abstract class HibernateDAO<EntityClass, IDType extends Serializable> implements DAOInterface<EntityClass, IDType> {
@Autowired
private SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sessionFactory){
this.sessionFactory=sessionFactory;
}
public void getSessionFactory(){
return this.sessionFactory;
}
// Implements all DAOInterface method using sessionFactory
}
// PERSON DAO INTERFACE
public interface PersonDAO extends DAOInterface<Person, Long>{
Person findByName(String name, String surname);
List<Person> getInAgeRange(int year1, int year2);
}
// PERSON HIBERNATE DAO IMPLEMENTATION
public PersonHDAO extends HibernateDAO<Person, Long> implements PersonDAO{
// Implements the methods of PersonDAO interface using sessionFactory
}
@Service
public class PersonService {
//spring inject the correct DAO by its xml config(in this case PersonHDAO
@Autowired
private PersonDAO personDAO;
// spring manage the transaction
@Transactional
public List<Person> getInAgeRange(int year1, int year2){
return personDAO.getInAgeRange(year1, year2);
}
}
// NOW... HOW USE IT
//let's assume i have a button, pressing it a table will be populated with all persons in age range
private void actionPerfom(ActionEvent e){
List<Person> list=personService.getInAgeRange(age1Spinner.getValue(), age2Spinner.getValue());
//Load a table with list
}
抱歉这堵文字墙,也许对我希望的其他人有用,我朝着正确的方向前进?我的服务层需要接口吗?都是正确分层的吗?我也需要控制层吗?
谢谢。