@Autowired 没有类型的限定 bean - Bean extending Abstract class

Question

我有一个包里的豆子 - data.dao

@Component("questionDao")
@Transactional
public class QuestionDao extends AbstractDao<Question, Long>{

}

(所有方法都在AbstractDao中实现) 我正在为这个 bean 编写 testClass 并且我使用这样的自动装配：

@Autowired
@Qualifier(value="questionDao")
private QuestionDao questionDao;

这样就没问题了！

现在我需要为 QuestionDao bean 添加非常具体的方法，所以我稍微改变了它：

@Component("questionDao")
@Transactional
public class QuestionDao extends AbstractDao<Question, Long>{
    public void doSomething(){
    }
}

一旦我修改了我的 bean（主体不为空）自动装配由于某种原因不起作用......“没有找到类型为 data.dao.QuestionDao 的符合条件的 bean 以供依赖。（我正在使用 Spring 4.x) 任何可能出错的想法（在场景 1 中它就像魅力一样工作但是一旦我触摸 QuestionDao class 它就无法自动装配）

这是我的 AbstractDao class

public class AbstractDao<T, ID extends Serializable> implements Dao<T, ID> {

    @Autowired
    protected SessionFactory sessionFactory;

    private Class<T> persistentClass;
    private Transaction transaction;

    @SuppressWarnings("unchecked")
    public AbstractDao() {
        this.persistentClass = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass())
                .getActualTypeArguments()[0];
    }

    protected Session getSession() {
        return sessionFactory.getCurrentSession();
    }

    public Class<T> getPersistentClass() {
        return persistentClass;
    }

    @SuppressWarnings("unchecked")
    @Override
    public T findById(ID id) {
        transaction = getSession().beginTransaction();

        T object = (T) getSession().load(this.getPersistentClass(), id);

        transaction.commit();

        return object;
    }

    @Override
    public List<T> findAll() {
        transaction = getSession().beginTransaction();

        List<T> list = this.findByCriteria();

        transaction.commit();

        return list;
    }

    @SuppressWarnings("unchecked")
    protected List<T> findByCriteria(Criterion... criterion) {
        Criteria crit = this.getSession().createCriteria(this.getPersistentClass());

        for (Criterion c : criterion) {
            crit.add(c);
        }
        return (List<T>) crit.list();
    }

    @Override
    public T create(T entity) {
        transaction = getSession().beginTransaction();

        getSession().saveOrUpdate(entity);

        transaction.commit();

        return entity;
    }

    @Override
    public void delete(T entity) {
        transaction = getSession().beginTransaction();

        getSession().delete(entity);

        transaction.commit();
    }

    @Override
    public void deleteTable() {
        transaction = getSession().beginTransaction();

        String deleteTable = new String ("delete " + this.getPersistentClass().getName());

        Query query = getSession().createQuery(deleteTable);
        query.executeUpdate();

        transaction.commit();
    }

}

这是 sessionFactory 的配置

<bean id="sessionFactory"
            class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
            <property name="dataSource" ref="dataSource"></property>
            <property name="hibernateProperties">
                <props>
                    <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQL9Dialect</prop>
                    <prop key="hibernate.show_sql">true</prop>
                </props>
            </property>
            <property name="packagesToScan">
                <list>
                    <value>sk.uniza.fri.cuka.data.dao</value>
                    <value>sk.uniza.fri.cuka.data.entity</value>
                </list>
            </property>
        </bean>

完整的堆栈跟踪：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sk.uniza.fri.cuka.test.tests.AnswerDaoTest': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private sk.uniza.fri.cuka.data.dao.QuestionDao sk.uniza.fri.cuka.test.tests.AnswerDaoTest.questionDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [sk.uniza.fri.cuka.data.dao.QuestionDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true), @org.springframework.beans.factory.annotation.Qualifier(value=questionDao)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1210)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:385)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:118)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:212)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:200)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runReflectiveCall(SpringJUnit4ClassRunner.java:259)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:261)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:219)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:83)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access[=16=]0(ParentRunner.java:58)
    at org.junit.runners.ParentRunner.evaluate(ParentRunner.java:268)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:68)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:163)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private sk.uniza.fri.cuka.data.dao.QuestionDao sk.uniza.fri.cuka.test.tests.AnswerDaoTest.questionDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [sk.uniza.fri.cuka.data.dao.QuestionDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true), @org.springframework.beans.factory.annotation.Qualifier(value=questionDao)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:561)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
    ... 26 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [sk.uniza.fri.cuka.data.dao.QuestionDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true), @org.springframework.beans.factory.annotation.Qualifier(value=questionDao)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1301)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1047)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:942)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:533)
    ... 28 more

编辑：问题已解决：我刚刚删除了“@Transactional”并且它有效。我还重构了一点我的 QuestionDao，因此它实现了 Peter Jurkovic 建议的接口。

Answer 1

嗯，现在通过您的编辑，我想知道这是否可能是由于您的抽象方法中的 @Autowired protected SessionFactory sessionFactory; 无法自动装配。你的堆栈跟踪中有更多信息吗？我会尝试用 @Autowired setter 或构造函数替换它。

像这样：

public class AbstractDao<T, ID extends Serializable> implements Dao<T, ID> {

    protected SessionFactory sessionFactory;

    @Autowired
    public AbstractDao(SessionFactory sessionFactory){
        this.sessionFactory= sessionFactory;
    }

///
}

然后你也需要在你的 QuestionDao 中创建一个构造函数

---- 未解决问题。

试试这个：

@Component
@Transactional
@Qualifier("questionDao")
public class QuestionDao extends AbstractDao<Question, Long>{
    public void doSomething(){
    }
}

Answer 2

Dao 接口有问题。从您的 QuestionDao 中提取界面，它应该可以工作。

public interface QuestionDao extends Dao<Question, Long>{
    public void doSomething();
}

创建 QuestionDaoImpl

@Transactional
@Repository("questionDao")
public class QuestionDaoImpl extends AbstractDao<Question, Long> implements QuestionDao{
    public void doSomething(){
    }
}

Answer 3

这个异常是由组件中的包扫描创建的，并添加这个xml配置文件<jpa:repositories base-package="sk.uniza.fri.cuka.data.dao"/>

@Autowired 没有类型的限定 bean - Bean extending Abstract class

@Autowired No qualifying bean of type - Bean extending Abstract class

spring

autowired