如何在春季自动接线通用bean [英] How to autowire a generic bean in spring

问题描述

如何在春季自动接线通用bean?

How to autowire a generic bean in spring?

我有一个dao工具，如下:

I have a dao implement as follows:

@Transactional
public class GenericDaoImpl<T> implements IGenericDao<T>
{

    private Class<T> entityClass;

    @Autowired
    private SessionFactory sessionFactory;

    public GenericDaoImpl(Class<T> clazz) {

        this.entityClass = clazz;
    }
    ...
}

现在，我想像这样自动连接DaoImpl:

Now I want to autowired the DaoImpl like this:

@Autowired
GenericDaoImpl<XXXEntity> xxxEntityDao;

我在spring xml中进行配置:

I config in the spring xml:

<bean id="xxxEntityDao" class="XXX.GenericDaoImpl">
    <constructor-arg name="clazz">
        <value>xxx.dao.model.xxxEntity</value>
    </constructor-arg>
    <property name="sessionFactory" ref="sessionFactory"/>
</bean>

但是我不工作，应该如何配置?或有关通用Dao工具的良好做法?

But I doesn't work, How should I config it? or a good practice about generic Dao implement?

推荐答案

使用您的界面而不是实现

Work with your interfaces instead of implementations

请勿在持久层中使用@Transactional，因为它很可能属于您的服务层.

Do not use @Transactional in your persistent layer as it is much more likely that it belongs to your service layer.

话虽如此，扩展通用的dao和autowire可能更有意义.例如:

Those being said, it might make more sense to extend the generic dao and autowire that. An example would be something like :

public interface UserDao extends GenericDao<User> {

    User getUsersByNameAndSurname(String name, String surname);
    ... // More business related methods
}

public class UserDaoImpl implements UserDao {

    User getUsersByNameAndSurname(String name, String surname);
    {
        ... // Implementations of methods beyond the capabilities of a generic dao
    }

    ...
}

@Autowired
private UserDao userDao; // Now use directly the dao you need

但是，如果您真的想以这种方式使用它，则必须声明一个限定符:

But if you really really want to use it that way you have to declare a qualifier :

@Autowired
@Qualifier("MyBean")
private ClassWithGeneric<MyBean> autowirable;

这篇关于如何在春季自动接线通用bean的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！