@Autowired没有类型的限定bean - Bean扩展Abstract类

Question

我在包中有一个bean - 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，我使用这样的自动装配：

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

这种方式没有任何问题！

现在我需要为QuestionDao bean添加非常具体的方法，所以我稍微改了一下：

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

一旦我修改我的bean（正文不为空），自动装配由于某种原因不起作用...＆＃34;没有找到依赖的data.dao.QuestionDao类型的限定bean。 （我使用的是Spring 4.x） 任何想法都可能出错（在场景1中它的功能就像魅力一样，但是当我触摸QuestionDao类时它就无法自动装配）

这是我的AbstractDao课程

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>

Full stackTrace：

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$1.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$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:68)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:163)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private sk.uniza.fri.cuka.data.dao.QuestionDao sk.uniza.fri.cuka.test.tests.AnswerDaoTest.questionDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [sk.uniza.fri.cuka.data.dao.QuestionDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true), @org.springframework.beans.factory.annotation.Qualifier(value=questionDao)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$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： 问题解决了：我刚刚删除了＆＃34; @Transactional＆＃34;它的工作原理。我还重构了一下我的QuestionDao，所以它实现了Peter Jurkovic所建议的界面。

Answer 1

Dao界面存在问题。从QuestionDao中提取界面，它应该有效。

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 2

嗯，现在通过编辑，我想知道是否可能是由于您的抽象方法中的@Autowired无法自动连接。你在堆栈跟踪中有更多信息吗？ 我尝试用public class AbstractDao<T, ID extends Serializable> implements Dao<T, ID> { protected SessionFactory sessionFactory; @Autowired public AbstractDao(SessionFactory sessionFactory){ this.sessionFactory= sessionFactory; } /// } setter或构造函数替换它。

类似的东西：

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

然后你还需要在QuestionDao中创建一个构造函数

----没有解决问题。

试试这个：

<!-- Main Toolbar -->
    <paper-toolbar id="mainToolbar" class="medium-tall">
      <!-- Application name -->
      <div class="app-name">Website</div>

      <span class="space"></span>

      <!-- Toolbar icons -->
      <paper-icon-button icon="refresh"></paper-icon-button>
      <paper-icon-button icon="search"></paper-icon-button>

      <!-- Application tabs -->
      <paper-tabs class="bottom" attr-for-selected="data-route" selected="[[route]]">
        <paper-tab link>
          <a data-route="home" href="{{baseUrl}}">
            <iron-icon icon="home"></iron-icon>
            <span>Home</span>
          </a>
        </paper-tab>
        <paper-tab link>
          <a data-route="artist" href="{{baseUrl}}artist">
            <iron-icon icon="home"></iron-icon>
            <span>Artist</span>
          </a>
        </paper-tab>
        <paper-tab link>
          <a data-route="teacher" href="{{baseUrl}}teacher">
            <iron-icon icon="home"></iron-icon>
            <span>Teacher</span>
          </a>
        </paper-tab>
        <paper-tab link>
          <a data-route="research" href="{{baseUrl}}research">
            <iron-icon icon="home"></iron-icon>
            <span>Research</span>
          </a>
        </paper-tab>
        <paper-tab link>
          <a data-route="contact" href="{{baseUrl}}contact">
            <iron-icon icon="mail"></iron-icon>
            <span>Contact</span>
          </a>
        </paper-tab>
      </paper-tabs>
    </paper-toolbar>

    <!-- Main Content -->
    <div class="content">
      <iron-pages attr-for-selected="data-route" selected="{{route}}">
        <section data-route="home">
          <paper-material elevation="1">
            <my-greeting></my-greeting>

            <p class="subhead">You now have:</p>
            <my-list></my-list>

            <p>Looking for more Web App layouts? Check out our <a href="https://github.com/PolymerElements/app-layout-templates">layouts</a> collection. You can also <a href="http://polymerelements.github.io/app-layout-templates/">preview</a> them live.</p>
          </paper-material>
        </section>

        <section data-route="artist">
          <paper-material elevation="1">
            <h2 class="page-title">Users</h2>
            <p>This is the users section</p>
            <a href$="{{baseUrl}}users/Addy">Addy</a><br>
            <a href$="{{baseUrl}}users/Rob">Rob</a><br>
            <a href$="{{baseUrl}}users/Chuck">Chuck</a><br>
            <a href$="{{baseUrl}}users/Sam">Sam</a>
          </paper-material>
        </section>

        <section data-route="teacher">
          <paper-material elevation="1">
            <h2 class="page-title">User: {{params.name}}</h2>
            <div>This is {{params.name}}'s section</div>
          </paper-material>
        </section>

        <section data-route="contact">
          <paper-material elevation="1">
            <h2 class="page-title">Contact</h2>
            <p>This is the contact section</p>
          </paper-material>
        </section>
      </iron-pages>
    </div>

Answer 3

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