通过类型为[java.lang.Class]的索引0的构造函数参数表示的不满意的依赖性

Question

嗨,大家好我用hibernate和spring创建了一个简单的web应用程序,我想实现一个包含crud操作的抽象类,但是我有这个错误:

    org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'clientService' defined in class path resource [applicationContext.xml]: 
Cannot resolve reference to bean 'clientDao' while setting bean property 'clientDao'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: 
Error creating bean with name 'clientDao' defined in class path resource [applicationContext.xml]: 
Unsatisfied dependency expressed through constructor argument with index 0 of type [java.lang.Class]: 

GenericDao

public interface GenericDao<T, ID extends Serializable> {

    T save(T entity);
    T update(T entity);
    void delete(T entity);
    T findById(ID id);
    List<T> findAll();
    void flush();

}

GenericDaoImpl

@Transactional
public  class GenericDaoImpl<T, ID extends Serializable> implements GenericDao<T, ID> {

    @Autowired
    SessionFactory sessionFactory ;

 private Class<T> persistentClass;



    public GenericDaoImpl() {
    super();
}

    public GenericDaoImpl(Class<T> persistentClass) {
    super();
    this.persistentClass = persistentClass;
}

    @Transactional
    public T save(T entity) {
        this.sessionFactory.getCurrentSession().save(entity);
        return null;
    }

    @Transactional
    public T update(T entity) {
        this.sessionFactory.getCurrentSession().update(entity);
        return null;
    }

    @Transactional
    public void delete(T entity) {
        this.sessionFactory.getCurrentSession().delete(entity);

    }

    @SuppressWarnings("unchecked")
    @Transactional
    public T findById(ID id) {
        return  (T) this.sessionFactory.getCurrentSession().load(this.getPersistentClass(), id);

    }
    @SuppressWarnings("unchecked")
    @Transactional
    public List<T> findAll() {
        return   this.sessionFactory.getCurrentSession().createQuery("* from"+this.getPersistentClass().getSimpleName()).list();
    }

    @Transactional
    public void flush() {
        this.sessionFactory.getCurrentSession().flush();

    }

    public SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    public void setSessionFactory(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }

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

    public void setPersistentClass(Class<T> persistentClass) {
        this.persistentClass = persistentClass;
    }



}

ClientDao

public interface ClientDao  extends GenericDao<Client,Integer>  {



}

ClientDaoImpl

@Transactional
@Repository("clientDao")
public class ClientDaoImpl extends GenericDaoImpl<Client,Integer>  implements ClientDao {






    public ClientDaoImpl(Class<Client> persistentClass) {
        super(persistentClass);

    }

application context.xml

<bean id="client" class="com.webapp.model.Client"/>

  <bean id="genericDao" class="com.webapp.dao.GenericDaoImpl">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>
    <bean id="clientDao" class="com.webapp.dao.ClientDaoImpl" parent="genericDao">
    <constructor-arg ref="client" />
   </bean>

 <bean id="clientService" class="com.webapp.service.ClientServiceImpl">
        <property name="clientDao" ref="clientDao" />
    </bean>

Answer 1

使用:

<bean id="clientDao" class="com.webapp.dao.ClientDaoImpl" parent="genericDao">
<constructor-arg >com.xxx.Client</constructor-arg >

Spring会将字符串"强制转换"为类.然后,您可以从XML中删除客户端bean.

或者从你的中移除这个参数ClientDaoImpl,因为它没用(它只能是这种类型,所以没有理由把它作为参数)

public ClientDaoImpl() {
    super(com.xxx.Client.class);
}