春季创建豆但不注入它 [英] Spring creating bean but not injecting it

问题描述

我知道关于Spring Autowired的问题有很多问题，但是我找不到与我类似的东西，如果抱歉，我很抱歉...

I know theres a ton of questions regarding problems with Spring Autowired, but I havent been able to find anything similar to mine, so sorry if its a dupe...

我在自动装配已创建的bean时遇到问题(调试显示该构造函数已运行)，但随后没有注入.没有手动实例化的调用. 我在项目中还有许多其他自动接线领域，它们工作正常. 不过，最有趣的是，我在不同的项目中使用了相同的模式和配置，并且在这里有效 ...

Im having problems with autowiring a bean that is created (debugging shows that the constructor is run), but then it doesnt get injected. There are no calls of manual instantiation. I have many other autowired fields in the project and they work fine. Most amusing, though, is the fact that Ive used the same pattern and config in a different project and it works there...

现在，这是代码:

创建但未注入的bean:

The bean that gets created but not injected:

@Component("genericDao")
public class GenericHibernateJpaDao implements GenericDao {

    @Autowired
    protected EntityManagerFactory entityManagerfactory;

    public GenericHibernateJpaDao() {
    }
    //getters, setters and dao methods
}

GenericDao接口仅定义方法，没有注释.

GenericDao interface only defines methods and has no annotations.

定义bean的服务超类:

Service super-class that defines the bean:

@Configurable
public abstract class AbstractService {
    @Autowired
    protected GenericDao genericDao;
    //getters, setters
}

服务实现(声明位):

@Service
@Component
public class WechatMessageService extends AbstractService implements IMessageService {

在genericDao.saveOrUpdate(n);处的服务实现中的断点显示genericDao为空(这也是抛出NullPointerEx的行.) IMessageService是

Breakpoint in service implementation at genericDao.saveOrUpdate(n); shows genericDao to be null (this is also the line that throws NullPointerEx.) IMessageService is

@Service
@Configurable
@Transactional

application-config.xml(相关位):

application-config.xml (relevant bits):

<beans .......... default-autowire="byName">
    <context:component-scan base-package="package.with.dao" />
    <context:component-scan base-package="package.with.service" />
    <context:spring-configured/> 

我想这只是我这边的一个愚蠢的错误，但我无法弄清楚，而谷歌搜索也无济于事.

Im guessing its just some fairly stupid mistake on my side, but I just cant figure it out and googling isnt helping.

感谢您的帮助.

推荐答案

好吧，事实证明，我在调试过程中误以为前提. 虽然我没有手动启动DAO bean，但是我在测试的初始化过程中创建了 service 的手动实例，因为我需要向其传递一个虚拟对象. 是的...

Well, turns out I was mistaken in my premise during debugging. While I had no manual initiation of the DAO bean, I was creating a manual instance of the service in the initialization of the tests, because I needed to pass it a dummy object. So yeah...

但是，感谢大家的帮助，因为它使我意识到了这一点，并帮助我更好地理解了Spring及其注释.

Thanks to everyone for the help though, as it nudged me to this realization and helped me understand Spring and its annotations better.

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