NoUniqueBeanDefinitionException：没有类型的限定bean ...我定义了，期望的单个匹配bean但找到了2

Question

我们一直在搜索互联网和平装课程，但似乎无法找到解决问题的方法：

Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [services.GebruikerDAO] is defined: expected single matching bean but found 2: gebruikerDAO,GebruikerDAO
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:863)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:768)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:486)
... 58 more

要绘制一些背景信息：我们必须使用java jsp页面创建一个小型网站，并使用弹簧安全性和maven使用数据库获取信息并检查信息。以下是我们所有的文件。

这是我们的GebruikerDAO课程：

package services;
import domein.Gebruiker;

public interface GebruikerDAO extends GenericDao<Gebruiker>{

    public Gebruiker getGebruikerByStamnummer(String stamnummer);

}

这是我们的JpaGebruikerDao课程：

@Repository("gebruikerDAO")
public class JpaGebruikerDao extends GenericDaoJpa<Gebruiker> implements GebruikerDAO{

    @PersistenceContext
    private EntityManager em;

    public JpaGebruikerDao()
    {
        super(Gebruiker.class);
    }

    /*@Override
    @Transactional
    public List<Gebruiker> findAll() {
        CriteriaBuilder criteriaBuilder = em.getCriteriaBuilder();
        CriteriaQuery<Gebruiker> criteriaQuery = criteriaBuilder.createQuery(Gebruiker.class);

        Root<Gebruiker> gebruiker = criteriaQuery.from(Gebruiker.class);

        criteriaQuery.orderBy(criteriaBuilder.desc(gebruiker.get(Gebruiker_.familienaam)));

    // JPQL select 
        criteriaQuery.select(gebruiker);

        TypedQuery<Gebruiker> query = em.createQuery(criteriaQuery);
        return query.getResultList();
    }*/

    // CRUD methods
    @Override
    @Transactional
    public Gebruiker update(Gebruiker gebruiker) {
        return em.merge(gebruiker);
    }

    @Override
    @Transactional(readOnly = true)
    public Gebruiker get(String id) {
        return em.find(Gebruiker.class, id);
    }

    @Override
    @Transactional
    public void insert(Gebruiker gebruiker) {
        em.persist(gebruiker);
    }

    @Override
    @Transactional
    public void delete(Gebruiker gebruiker) {
        em.remove(em.merge(gebruiker));
    }

    @Override
    public Gebruiker getGebruikerByStamnummer(String stamnummer) {
        return get(stamnummer);
    }
}

这是我们的Controller类：

@Controller
public class PlanningController {

    @Autowired
    @Qualifier("GebruikerDAO")
    private GebruikerDAO gebruikerDao;

    @RequestMapping(value = "/planning", method = RequestMethod.GET)
    public String listGuest(Model model)
    {
        List<Gebruiker> gebruikerlijst = gebruikerDao.findAll();
        List<Student> studentlijst = new ArrayList<>();

        for (Gebruiker s : gebruikerlijst) {
            if (s instanceof Student){
                Student student = (Student)s;
                if(student.getLokaal() != null)
                {
                    studentlijst.add(student);
                }
            }
        }
        // there is more but it just checks for if a timeslot is available in our planning

这是我们的spring-security文件：

<beans:beans xmlns="http://www.springframework.org/schema/security"
         xmlns:beans="http://www.springframework.org/schema/beans"
         xmlns:p="http://www.springframework.org/schema/p"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="
            http://www.springframework.org/schema/security
            http://www.springframework.org/schema/security/spring-security-3.1.xsd
            http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">

<beans:import resource="applicationContext.xml"/>

<http auto-config="true">
    <intercept-url pattern="/admin*" access="hasAnyRole('ROLE_Student', 'ROLE_Promotor', 'ROLE_Coordinator')"/>
    <logout logout-success-url="/planning.htm"/>
    <access-denied-handler ref="accessDeniedHandler"/>
    <remember-me/>
</http>

<authentication-manager>
    <authentication-provider>
        <password-encoder hash="sha-256"/>
        <jdbc-user-service data-source-ref="dataSource"
                           users-by-username-query="select StamNummer, WachtwoordEncrypted, 'true' as enabled from gebruiker where StamNummer=?"
                           authorities-by-username-query="select StamNummer, Type as authority from gebruiker where StamNummer=?"
                           role-prefix="ROLE_"
        />
    </authentication-provider>
</authentication-manager>

<beans:bean class="org.springframework.security.web.access.expression.DefaultWebSecurityExpressionHandler"/>

这是我们的applicationContext文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:p="http://www.springframework.org/schema/p"
   xmlns:aop="http://www.springframework.org/schema/aop"
   xmlns:tx="http://www.springframework.org/schema/tx"
   xsi:schemaLocation="http://www.springframework.org/schema/beans       http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
   http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
   http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">

    <bean name = "GebruikerDAO" class="services.JpaGebruikerDao"/>
</beans>

这是我们的dispatcher-servlet文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:p="http://www.springframework.org/schema/p"
   xmlns:aop="http://www.springframework.org/schema/aop"
   xmlns:tx="http://www.springframework.org/schema/tx"
   xmlns:mvc="http://www.springframework.org/schema/mvc"
   xmlns:context="http://www.springframework.org/schema/context"
   xmlns:jee="http://www.springframework.org/schema/jee"
   xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-3.1.xsd">   

<mvc:annotation-driven />
<context:component-scan base-package="controller"/>
<context:component-scan base-package="services"/>

<bean id="accessDeniedHandler" class="handler.MyAccessDeniedHandler">
    <property name="accessDeniedUrl" value="403"/>
</bean>

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost:3306/bachelorproef"/> <!--  jdbc:mysql://localhost:3306/mysql?zeroDateTimeBehavior=convertToNull-->
    <property name="username" value="root"/>
    <property name="password" value="root"/>
</bean>
<bean id="entityManagerFactory"
      class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="packagesToScan">
        <list>
            <value>domein</value>
        </list>
    </property>
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
            <property name="showSql" value="true" /> 
            <property name="generateDdl" value="true" />
            <property name="database" value="MYSQL"/>
        </bean>
    </property>
</bean>

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

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

<bean id="viewResolver"
      class="org.springframework.web.servlet.view.InternalResourceViewResolver"
      p:prefix="/WEB-INF/jsp/"
      p:suffix=".jsp" />
</beans>

这是我们的web.xml文件：

<web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-   app_2_4.xsd">
<display-name>Spring MVC Application</display-name> 
<servlet>
    <servlet-name>dispatcher</servlet-name> 
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> 
    <load-on-startup>1</load-on-startup> 
</servlet>
<servlet-mapping>
    <servlet-name>dispatcher</servlet-name> 
    <url-pattern>/</url-pattern> 
</servlet-mapping>
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> 
</listener>
<context-param>
    <param-name>contextConfigLocation</param-name> 
    <param-value>/WEB-INF/dispatcher-servlet.xml, 
                            /WEB-INF/spring-security2.xml
    </param-value> 
</context-param> 
<filter>
    <filter-name>springSecurityFilterChain</filter-name> 
    <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class> 
</filter>
<filter-mapping>
    <filter-name>springSecurityFilterChain</filter-name> 
    <url-pattern>/*</url-pattern> 
</filter-mapping>
</web-app>

这是我们的Gebruiker课程：

@Entity
@Table(name = "gebruiker")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "Type")
public abstract class Gebruiker implements Serializable {

@Id
@Column(name = "StamNummer")
private String stamNummer;
@Column(name = "Familienaam")
private String familienaam;
@Column(name = "Voornaam")
private String voornaam;
@Column(name = "Email")
private String email;
@Column(name = "Wachtwoord")
private String wachtwoord;
@Column(name = "Campus")
private String campus;
@Transient
private String naam;

public Gebruiker() {

}
(+ some extra getters, setters and generatePassword methods)

这是我们的学生班：

@Entity
@DiscriminatorValue("Student")
public class Student extends Gebruiker{

@ManyToOne
private Promotor promotor;

@OneToOne
@JoinColumn(name = "HuidigDossier_DossierId")
private Dossier dossier;

@Temporal(TemporalType.TIMESTAMP)
private Date datumPresentatie;  

private String lokaal;
(+ some getters, setters and toString)

这是我们的推广课程：

@Entity
@DiscriminatorValue("Promotor")
public class Promotor extends Gebruiker {

    @OneToMany(mappedBy="promotor")
    List<Student> studenten;

    public Promotor(){
         studenten = new ArrayList<>();
    }

    public List<Student> getStudenten() {
        return studenten;
    }

    public void setStudenten(List<Student> studenten) {
        this.studenten = studenten;
    }

}

这是我们的BPCoordinator类：

@Entity
@DiscriminatorValue("Coordinator")
public class BPCoordinator extends Gebruiker{

    public BPCoordinator(){

    }
}

我知道如果NoUniqueBeanDefinitionException错误发生，有很多信息可以找到，但这几乎总是指实体管理器，在这里他说gebruikerDAO和GebruikerDAO都找不到，我们不知道他在哪里从中获取它们或为什么会发生此错误。大部分代码几乎都是纯粹的其他学校项目和paperbackcode的复制粘贴（我们的课程由我们的课程给出）

想法在何处以及如何解决问题将是惊人的。

Answer 1

从XML配置中删除<bean name = "GebruikerDAO" class="services.JpaGebruikerDao"/>（如果配置中存在所有内容，我建议您删除整个文件）。

这是必需的，因为JpaGebruikerDao已经通过组件扫描（名称为gebruikerDAO）注册为（存储库）bean。

Answer 2

从类JpaGebruikerDao中删除@Repository（＆＃34; gebruikerDAO＆＃34;）注释，因为它已经注册， 或删除

Answer 3

此异常有两种可能的解决方案。 1-仅在XML文件中定义类并使用@Qualifier：

public class PlanningController {

@Autowired
@Qualifier("GebruikerDAO")
private GebruikerDAO gebruikerDao;

在XML中仅为PlanningController定义一个bean

2-或者删除Qualifier注释，然后在PlanningController中添加getter和setter或构造函数，然后在XML中使用属性定义上下文：

<bean class="[path of PlanningController]">
<property name="gebruikerDao" ref="[GebruikerDAO implementation bean name]"/>

Answer 4

在这种情况下，我们可以使用

@Inject
@Named("GebruikerDAO")
private GebruikerDAO gebruikerDao;

这将消除对使用什么实现的混淆。