Question

我在使用Hibernate 4.2的Web应用程序中工作，我实现了抽象工厂模式但是为了创建会话工厂我没有init方法因为我使用第一次调用来创建会话工厂以重用像静态一样前进，就像你可以看到我从DAOImpl获得会话，工作，最后我关闭它。首先，我想问一下这种做法是否正确？还有其他更好的做法吗？

public class HibernateSessionFactory {

    private static SessionFactory sessionFactory = buildSessionFactory();

    private static final Logger logger = LogManager.getLogger(HibernateSessionFactory.class);

    private static SessionFactory buildSessionFactory() {
        try {

            Configuration configuration = new Configuration();
            configuration.configure("hibernate.cfg.xml");

            ServiceRegistry sr = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
            SessionFactory sf = configuration.buildSessionFactory(sr);

            return sf;

        } catch (Exception ex) {
            logger.error("Initial SessionFactory creation failed.", ex);
            ex.printStackTrace();
            throw  ex;

        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    public static void shutdownSessionFactory() {
        sessionFactory.close();
    }

}

DAOIMPL

public class RecordDAOImpl implements RecordDAO{.....

public String getRecord (Long id){
        Session session = HibernateSessionFactory.getSessionFactory().openSession();


        try {
            session.beginTransaction();     
            .
            .
            .

            session.getTransaction().commit();

        } catch (Exception e) {
            session.getTransaction().rollback();
        } finally {
            session.close();
        }

        return value;
    }

DAO

    public interface FieldDAO {.....

String getRecord (Long id);

工厂

public class HibernateFactoryDao extends DAOFactory {...

@Override
    public RecordDAOImpl getRecordDAO() {
        return new RecordDAOImpl();
    }

Answer 1

作为替代方案，您可以使用CDI将工厂注入RecordDAOImpl并根据您的ORM类型检索您的会话。

作为一个可能的例子，您可以尝试以下方法：

1。在您的ORM工厂之间创建一个限定符

@Qualifier
@Retention(RUNTIME)
@Target({ TYPE, METHOD, FIELD, PARAMETER })
public @interface ORMSessionFactory {

    ORMType value();

    public enum ORMType {
        HIBERNATE,
        ECLIPSELINK;
    }
}

2. 为会话工厂定义界面

public interface MySessionFactory {

    public SessionFactory getSessionFactory();

    public void shutdownSessionFactory();
}

3. 如有必要，创建一个抽象类，其中包含所有ORM工厂实现中的常见行为

public abstract class AbstractSessionFactory implements MySessionFactory {

    protected SessionFactory sessionFactory;

    public AbstractSessionFactory() {
        buildSessionFactory();
    }

    @Override
    public SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    @Override
    public void shutdownSessionFactory() {
        if (sessionFactory != null) {
            sessionFactory.close();
        }
    }

    protected abstract SessionFactory buildSessionFactory();
}

4. 使用相应的类型

注释您的ORM工厂实施

@ORMSessionFactory(ORMType.HIBERNATE)
public class HibernateSessionFactory extends AbstractSessionFactory {

    @Override
    protected SessionFactory buildSessionFactory() {
        try {

            Configuration configuration = new Configuration();
            configuration.configure("hibernate.cfg.xml");

            ServiceRegistry sr = new StandardServiceRegistryBuilder()
                .applySettings(configuration.getProperties()).build();
            sessionFactory = configuration.buildSessionFactory(sr);

            return sessionFactory;

        } catch (Exception ex) {
            throw ex;
        }
    }
}

5. 然后，在RecordDAOImpl您可以执行以下操作

public class RecordDAOImpl implements RecordDAO {

    @Inject
    @ORMSessionFactory(ORMType.HIBERNATE)
    private MySessionFactory mySessionFactory;

    @Override
    public String getRecord(Long id) {
        String value = null;
        Session session = mySessionFactory.getSessionFactory().openSession();

        try {
            session.beginTransaction();

            // do some transactional stuff

            session.getTransaction().commit();

        } catch (Exception e) {
            session.getTransaction().rollback();
        } finally {
            session.close();
        }

        return value;
    }
}

不要忘记，为了启用CDI，您应该在 META-INF （JAR）或 WEB-中包含 beans.xml INF 文件夹（WAR）：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://xmlns.jcp.org/xml/ns/javaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee 
                           http://xmlns.jcp.org/xml/ns/javaee/beans_1_1.xsd"
version="1.1" bean-discovery-mode="all">
</beans>

Hibernate 4在Abstract Factory

1 个答案: