java - Spring @autowired 不起作用

Question

我在通过注解使用 spring DI 时遇到问题，这是我的应用程序:

@Service
public class Test {

    @Autowired
    private GpsPointEntityDao gpsPointEntityDao;

    public void test() {

        if (gpsPointEntityDao == null)
            System.out.println("It's null!\n" + gpsPointEntityDao);

    }
}

通用接口(interface):

public interface GenericDao<T extends DomainObject> {

    public T find(long id);

    public List<T> getAll();

    public void save(T object) throws DataAccessException;

    public void delete(T object) throws DataAccessException;

}

具体接口(interface):

public interface GpsPointEntityDao extends GenericDao<GpsPointEntity> {}

抽象实现:

abstract class AbstractGenericDaoJpa<T extends DomainObject> implements GenericDao<T> {

    private final Class<T> entityType;

    protected EntityManager entityManager;

    public AbstractGenericDaoJpa() {
        this.entityType = (Class<T>) GenericTypeResolver.resolveTypeArgument(getClass(), GenericDao.class);
    }

    @PersistenceContext
    public void setEntityManager(EntityManager entityManager) {
        this.entityManager = entityManager;
    }

    @Transactional
    @Override
    public T find(long id) {
        return entityManager.find(entityType, id);
    }

    @Transactional
    @Override
    public List<T> getAll() {
        return entityManager.createQuery("SELECT e FROM " + entityType.getName() + " e").getResultList();
    }

    @Transactional
    @Override
    public void save(T object) throws DataAccessException {
        entityManager.persist(object);
    }

    @Transactional
    @Override
    public void delete(T object) throws DataAccessException {
        entityManager.remove(object);
    }

}

具体类:

@Repository
public class GpsPointEntityDaoJpa extends AbstractGenericDaoJpa<GpsPointEntity> implements GpsPointEntityDao {}

还有我的应用上下文:

<context:component-scan base-package="com.test"/>

<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>

<bean id="entityManagerFactory"
      class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
      p:dataSource-ref="basicDataSource"/>

<bean id="transactionManager"
      class="org.springframework.orm.jpa.JpaTransactionManager"
      p:entityManagerFactory-ref="entityManagerFactory"/>

<tx:annotation-driven mode="proxy" transaction-manager="transactionManager"/>

<bean class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/>

应用程序的结果是:

为空!

我整天都在寻找问题，但没有成功。有人在哪里看到问题？

我在日志中发现了这条消息:

INFO  org.springframework.context.support.ClassPathXmlApplicationContext - Bean 'entityManagerFactory' of type [class org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)

Answer 1

我认为这没有问题。使用与您发布的大致相同的代码，我运行了这个:

public static void main(String[] args) {
    Test bean = new ClassPathXmlApplicationContext("/applicationContext.xml").getBean(Test.class);
    bean.test();
}

测试 bean 已正确注入(inject)。如果您想看一下，我可以提供我的测试项目。你确定你得到的是注入(inject)版本的测试吗？你是如何获得它的？

编辑:您的实例未被注入(inject)，因为您自己实例化它而不是让 Spring 执行它。除非你use AspectJ to inject objects , Spring 可以/将仅 注入(inject)它正在管理的对象。当您调用 new Test() 时，您并没有从 Spring 获取实例，而且 Spring 对您创建的实例一无所知。