相关疑难解决方法(0)

这个问题曾经在这里被问到过简单CRUD的EJB 3会话Bean设计,我只想更深入地询问有关此设计的问题.我已经尝试在原帖上提问,但是,我没有看到任何回复,所以我决定创建新帖子.因此,实现通用CRUD会话bean的Pascal解决方案如下

public interface GenericCrudService {
    public <T> T create(T t);
    public <T> T find(Class<T> type, Object id);
    public <T> void delete(T t);
    public <T> T update(T t);
    public List findWithNamedQuery(String queryName);
    public List findWithNamedQuery(String queryName, int resultLimit);
    public List findWithNamedQuery(String namedQueryName, 
                                   Map<String, Object> parameters);
    public List findWithNamedQuery(String namedQueryName, 
                                   Map<String, Object> parameters,
                                   int resultLimit);
    public <T> List<T> findWithNativeQuery(String sql, Class<T> type);
}

和

@Stateless
@Remote(GenericCrudService.class)
@TransactionAttribute(TransactionAttributeType.MANDATORY)
public class GenericCrudServiceBean implements GenericCrudService {
    @PersistenceContext
    private EntityManager em;

    @Override
    public …