java - 与 Spring/Hibernate3 的多对多关系问题

Question

我正在开发一个结合了 GWT、Spring MVC 和 Hibernate 的应用程序（具体来说，我使用 Hibernate 3 jar 库）。我是 Hibernate 的新手，我需要使用以下模型。

所以在 Node 和 Wall、Room 和 Wall 之间，我需要有 ManyToMany 的关系。

下面是Node实体类的代码：

package sk.jakub.app.shared.model;

@Entity
public class Node implements Serializable{
    private static final long serialVersionUID = -5924198459524011627L;

    private Long id; //id of the concrete node
    private float x, y;

    @ManyToMany
    private Collection<Wall> walls;

    public Node(){
        walls = new ArrayList<Wall>();
    }

    @Id
    @Column(name = "NODE_ID")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    //getters and setters for x,y omitted

    public void addWall(Wall wall){
        if(!getWalls().contains(wall))
            getWalls().add(wall);
        if(!wall.getNodes().contains(this))
            wall.getNodes().add(this);
    }

    public Collection<Wall> getWalls(){
        return walls;
    }   
}

和Wall .java 实体类：

package sk.jakub.app.shared.model;

@Entity
public class Wall implements Serializable{
    private static final long serialVersionUID = -5924198459524011627L;

    private Long id;
    private String type;

    @ManyToMany
    private Collection<Room> rooms;

    @ManyToMany(targetEntity=Node.class, mappedBy="walls", fetch=FetchType.EAGER)
    private Collection<Node> nodes;

    public Wall(){
        nodes = new ArrayList<Node>();
    }

    @Id
    @Column(name = "WALL_ID")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    //getters and setters for type omitted

    public Collection<Node> getNodes(){
        return nodes;
    }

    public void addNode(Node node){
        if(!getNodes().contains(node))
            getNodes().add(node);
        if(!node.getWalls().contains(this))
            node.getWalls().add(this);
    }

    public Collection<Room> getRooms(){
        return rooms;
    }

    public void addRoom(Room room){
        if(!getRooms().contains(room))
            getRooms().add(room);
        if(!room.getWallsH().contains(this))
            room.getWallsH().add(this);
    }
}

Room .java 实体类：

package sk.jakub.app.shared.model;

@Entity
public class Room implements Serializable{
    private static final long serialVersionUID = -5924198459524011627L;

    private Long id;
    private String name;
    private String description;

    @ManyToMany(targetEntity=Wall.class, mappedBy="rooms", fetch=FetchType.EAGER)
    private Collection<Wall> wallsH;

    public Room(){
        wallsH = new ArrayList<Wall>();
    }

    @Id
    @Column(name = "ROOM_ID")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }

    //getters and setters for name and descritpion omitted

    public Collection<Wall> getWallsH(){
        return wallsH;
    }

    public void addWallsH(Wall wall){
        if(!getWallsH().contains(wall))
            getWallsH().add(wall);
        if(!wall.getRooms().contains(this))
            wall.getRooms().add(this);
    }
}

现在是 DAO（数据访问对象）。

节点道：

package sk.jakub.app.server.dao;

@Repository
public class NodeDAO {

    @Autowired
    private HibernateTemplate hibernate;

    public Node get(Long id){
        return hibernate.get(Node.class, id);
    }

    public void delete(Node entity){
        hibernate.delete(entity);
    }

    public void save(Node entity){
        hibernate.saveOrUpdate(entity);
    }

    private Session getCurrentSession(){
        return hibernate.getSessionFactory().getCurrentSession();
    }   
}

墙道：

package sk.jakub.app.server.dao;

@Repository
public class WallDAO {

    @Autowired
    private HibernateTemplate hibernate;

    public Wall get(Long id){
        return hibernate.get(Wall.class, id);
    }

    public void delete(Wall entity){
        hibernate.delete(entity);
    }

    public void save(Wall entity){
        hibernate.saveOrUpdate(entity);
    }

    private Session getCurrentSession(){
        return hibernate.getSessionFactory().getCurrentSession();
    }
}

房间道：

package sk.jakub.app.server.dao;

@Repository
public class RoomDAO {

    @Autowired
    private HibernateTemplate hibernate;

    public Room get(Long id){
        return hibernate.get(Room.class, id);
    }

    public void delete(Room entity){
        hibernate.delete(entity);
    }

    public void save(Room entity){
        hibernate.saveOrUpdate(entity);
    }

    private Session getCurrentSession(){
        return hibernate.getSessionFactory().getCurrentSession();
    }   
}

现在这里是 Spring MVC applicationContext.xml：

<?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:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/tx 
                        http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
                        http://www.springframework.org/schema/beans 
                        http://www.springframework.org/schema/beans/spring-beans.xsd
                        http://www.springframework.org/schema/context
                        http://www.springframework.org/schema/context/spring-context-2.5.xsd
                        http://www.springframework.org/schema/aop 
                        http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">

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

<!-- NASTAVENIE KORENOVEHO BALIKA -->
<context:component-scan base-package="sk.jakub.app.server"/>
<aop:aspectj-autoproxy/>

<bean id="databaseProperties" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">

</bean>

<!-- UDAJE PRE PRIPOJENIE DO DATABAZY A VYTVORENIE BEANU PRE DATA SOURCE -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <property name="url" value="jdbc:mysql://localhost:3306/editor" />
    <property name="username" value="root" />
    <property name="password" value="gk04006c" />
    <property name="driverClassName" value="com.mysql.jdbc.Driver" />
    <property name="maxActive" value="100" />
    <property name="maxIdle" value="30" />
    <property name="maxWait" value="-1" />
    <property name="defaultAutoCommit" value="false" />
</bean>


<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>

<!-- NASTEAVENIE DIALEKTU PRE HIBERNATE A POD -->
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean" destroy-method="destroy">
    <property name="configurationClass" value="org.hibernate.cfg.AnnotationConfiguration" />
    <property name="dataSource" ref="dataSource" />
    <property name="packagesToScan" value="sk.jakub.app.shared.model" />
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.show_sql">false</prop>
            <prop key="hibernate.format_sql">true</prop>
            <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
            <prop key="hibernate.hbm2ddl.auto">create</prop>
            <prop key="hibernate.id.new_generator_mappings">true</prop>
        </props>
    </property>
</bean>

<!-- NASTAVEIE HIBERNATE TEMPLATE PRE PRIPOJENIE KU DATABAZE, TEN JE POTOM PRIPRAVENY NA AUTOWIRING DO SAMOTNEHO JAVOVSKEHO KODU -->
<bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>

</beans>

问题是我收到以下错误消息：

Starting Jetty on port 8888
   [WARN] Failed startup of context com.google.gwt.dev.shell.jetty.JettyLauncher$WebAppContextWithReload@1d69af9f{/,/home/jakub/ws/Editor1/war}
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'roomDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.orm.hibernate3.HibernateTemplate sk.jakub.app.server.dao.RoomDAO.hibernate; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateTemplate' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is org.hibernate.MappingException: Could not determine type for: java.util.Collection, at table: Wall, for columns: [org.hibernate.mapping.Column(nodes)]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:285)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1074)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)
    at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:276)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:197)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:47)
    at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:543)
    at org.mortbay.jetty.servlet.Context.startContext(Context.java:136)
    at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1220)
    at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:513)
    at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448)
    at com.google.gwt.dev.shell.jetty.JettyLauncher$WebAppContextWithReload.doStart(JettyLauncher.java:468)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
    at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
    at org.mortbay.jetty.handler.RequestLogHandler.doStart(RequestLogHandler.java:115)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
    at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
    at org.mortbay.jetty.Server.doStart(Server.java:222)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
    at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:672)
    at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509)
    at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1068)
    at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:811)
    at com.google.gwt.dev.DevMode.main(DevMode.java:311)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.orm.hibernate3.HibernateTemplate sk.jakub.app.server.dao.RoomDAO.hibernate; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateTemplate' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is org.hibernate.MappingException: Could not determine type for: java.util.Collection, at table: Wall, for columns: [org.hibernate.mapping.Column(nodes)]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:502)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:84)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:282)
    ... 31 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateTemplate' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is org.hibernate.MappingException: Could not determine type for: java.util.Collection, at table: Wall, for columns: [org.hibernate.mapping.Column(nodes)]
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:328)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:106)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1325)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1086)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:844)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:786)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:703)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:474)
    ... 33 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is org.hibernate.MappingException: Could not determine type for: java.util.Collection, at table: Wall, for columns: [org.hibernate.mapping.Column(nodes)]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1420)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:322)
    ... 46 more
Caused by: org.hibernate.MappingException: Could not determine type for: java.util.Collection, at table: Wall, for columns: [org.hibernate.mapping.Column(nodes)]
    at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:291)
    at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:275)
    at org.hibernate.mapping.Property.isValid(Property.java:217)
    at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:464)
    at org.hibernate.mapping.RootClass.validate(RootClass.java:236)
    at org.hibernate.cfg.Configuration.validate(Configuration.java:1193)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1378)
    at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:954)
    at org.springframework.orm.hibernate3.LocalSessionFactoryBean.newSessionFactory(LocalSessionFactoryBean.java:860)
    at org.springframework.orm.hibernate3.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:779)
    at org.springframework.orm.hibernate3.AbstractSessionFactoryBean.afterPropertiesSet(AbstractSessionFactoryBean.java:211)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1477)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417)
    ... 53 more
   [WARN] Nested in org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'roomDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.orm.hibernate3.HibernateTemplate sk.jakub.app.server.dao.RoomDAO.hibernate; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateTemplate' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is org.hibernate.MappingException: Could not determine type for: java.util.Collection, at table: Wall, for columns: [org.hibernate.mapping.Column(nodes)]:
org.hibernate.MappingException: Could not determine type for: java.util.Collection, at table: Wall, for columns: [org.hibernate.mapping.Column(nodes)]
    at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:291)
    at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:275)
    at org.hibernate.mapping.Property.isValid(Property.java:217)
    at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:464)
    at org.hibernate.mapping.RootClass.validate(RootClass.java:236)
    at org.hibernate.cfg.Configuration.validate(Configuration.java:1193)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1378)
    at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:954)
    at org.springframework.orm.hibernate3.LocalSessionFactoryBean.newSessionFactory(LocalSessionFactoryBean.java:860)
    at org.springframework.orm.hibernate3.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:779)
    at org.springframework.orm.hibernate3.AbstractSessionFactoryBean.afterPropertiesSet(AbstractSessionFactoryBean.java:211)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1477)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:322)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:106)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1325)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1086)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:844)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:786)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:703)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:474)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:84)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:282)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1074)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)
    at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:276)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:197)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:47)
    at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:543)
    at org.mortbay.jetty.servlet.Context.startContext(Context.java:136)
    at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1220)
    at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:513)
    at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448)
    at com.google.gwt.dev.shell.jetty.JettyLauncher$WebAppContextWithReload.doStart(JettyLauncher.java:468)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
    at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
    at org.mortbay.jetty.handler.RequestLogHandler.doStart(RequestLogHandler.java:115)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
    at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
    at org.mortbay.jetty.Server.doStart(Server.java:222)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
    at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:672)
    at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509)
    at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1068)
    at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:811)
    at com.google.gwt.dev.DevMode.main(DevMode.java:311)

我认为问题可能出在定义多对多关系的集合中。我为 ManyToMany 的集合尝试了 @ElementCollection 注释，但它不起作用。

非常感谢您的任何建议、想法和帮助:)

Answer 1

您必须选择：要么注释 getter，要么注释字段。但不是两者兼而有之。

如果@Id在 getter 上，则字段的所有注释都将被忽略。如果@Id是在一个字段上，那么 getter 上的所有注释都将被忽略。