Hibernate 多对多关系：如何修复 org.hibernate.exception.GenericJDBCException：无法初始化集合异常？答案

【问题标题】：Hibernate Many-toMany relationship: How to fix org.hibernate.exception.GenericJDBCException: could not initialize a collection exception?Hibernate 多对多关系：如何修复 org.hibernate.exception.GenericJDBCException：无法初始化集合异常？
【发布时间】：2012-08-07 20:55:10
【问题描述】：

我正在使用休眠站点上的 hibernate_reference.pdf 使用休眠多对多关联。我正在使用文档中描述的相同实体 Event.java 和 Person.java。

我看到许多人面临“无法初始化集合异常”，许多人解决了这个问题，但堆栈溢出帖子中提到的解决方案都没有解决我的问题。可能是这些解决方案不适用于多对多关联，或者我的配置有问题。以下是我的 hbm.xml 文件：

Event.hbm.xml：

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="roseindia.tutorial.hibernate">
    <class name="Event" table="EVENTS">

        <id name="id" column="EVENT_ID">
            <generator class="native" />
        </id>

        <property name="date" type="timestamp" column="EVENT_DATE" />
        <property name="title" type="string" />
        <property name="location" type="string" column="LOC" />

        <set name="participants" table="PERSON_EVENT" inverse="true" lazy="false" cascade="all" >
            <key column="EVENT_ID" not-null="true" />
            <many-to-many column="PERSON_ID" class="Person" />
        </set>
    </class>
</hibernate-mapping>

Event.java

public class Event implements java.io.Serializable {
    private long id;
    private String title;
    private Date date;
    private String location;

    public Event() {
        //participants = new HashSet<Person>(0);
    }

    private Set participants = new HashSet(0);

    public Set getParticipants() {
        return participants;
    }

    public void setParticipants(Set participants) {
        this.participants = participants;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((date == null) ? 0 : date.hashCode());
        //result = prime * result + (int) (id ^ (id >>> 32));
        result = prime * result
                + ((location == null) ? 0 : location.hashCode());
        //result = prime * result + ((participants == null) ? 0 : participants.hashCode());
        result = prime * result + ((title == null) ? 0 : title.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Event other = (Event) obj;
        if (date == null) {
            if (other.date != null)
                return false;
        } else if (!date.equals(other.date))
            return false;

        if (location == null) {
            if (other.location != null)
                return false;
        } else if (!location.equals(other.location))
            return false;

        if (title == null) {
            if (other.title != null)
                return false;
        } else if (!title.equals(other.title))
            return false;
        return true;
    }

    @SuppressWarnings("unchecked")
    public void addToParticipants(Person person) {
        this.getParticipants().add(person);
        //person.addToEvent(this);
        person.getEvents().add(this);
    }

    public void removeFromParticipants(Person person) {
        this.getParticipants().remove(this);
        person.getEvents().remove(person);
    }

    public long getId() {
        return id;
    }

    private void setId(long id) {
        this.id = id;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getLocation() {
        return this.location;
    }

    public void setLocation(String location) {
        this.location = location;
    }
}

Person.hbm.xml：

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="roseindia.tutorial.hibernate">
    <class name="Person" table="PERSON">
        <id name="id" column="PERSON_ID">
            <generator class="native" />
        </id>
        <property name="age" />
        <property name="firstname" />
        <property name="lastname" />

        <set name="events" table="PERSON_EVENT" inverse="false" lazy="true" cascade="all" >
            <key column="PERSON_ID" not-null="true" />
            <many-to-many column="EVENT_ID" class="Event" />
        </set>

        <set name="emailAddresses" table="PERSON_EMAIL_ADDR">
            <key column="PERSON_ID" />
            <element type="string" column="EMAIL_ADDR" />
        </set>
    </class>
</hibernate-mapping>

Person.java

import java.util.HashSet;
import java.util.Set;

public class Person implements java.io.Serializable {
    private Set events = new HashSet<Event>();
    private Set emailAddresses = new HashSet();

    public Set getEmailAddresses() {
        return emailAddresses;
    }

    public void setEmailAddresses(Set emailAddresses) {
        this.emailAddresses = emailAddresses;
    }

    public void addToEvent(Event event) {
        this.getEvents().add(event);
        //event.addToParticipants(this);
        event.getParticipants().add(this);
    }

    public void removeFromEvent(Event event) {
        this.getEvents().remove(event);
        //event.removeFromParticipants(this);
        event.getParticipants().remove(this);
    }

    public Set getEvents() {
        return events;
    }

    public void setEvents(Set events) {
        this.events = events;
    }

    public Long getId() {
        return id;
    }

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

    public int getAge() {
        return age;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + age;
        result = prime * result
                + ((firstname == null) ? 0 : firstname.hashCode());
        result = prime * result
                + ((lastname == null) ? 0 : lastname.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Person other = (Person) obj;
        if (age != other.age)
            return false;

        if (firstname == null) {
            if (other.firstname != null)
                return false;
        } else if (!firstname.equals(other.firstname))
            return false;

        if (lastname == null) {
            if (other.lastname != null)
                return false;
        } else if (!lastname.equals(other.lastname))
            return false;
        return true;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getFirstname() {
        return firstname;
    }

    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }

    public String getLastname() {
        return lastname;
    }

    public void setLastname(String lastname) {
        this.lastname = lastname;
    }

    private Long id;
    private int age;
    private String firstname;
    private String lastname;

    public Person() {
    }
}

ManyToManyExample.java

public class ManyToManyExample {

    /**
     * @param args
     */
    public static void main(String[] args) {
        Session session = null;
        try {
            SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
            session = sessionFactory.openSession();
            Transaction tx1 = session.beginTransaction();

            System.out.println("Loading Record");
            Event theEvent = (Event) session.get(Event.class, new Long(1));
            session.refresh(theEvent);
            Person person = new Person();
            person.setAge(31);
            person.getEvents().add(theEvent);
            person.setFirstname("RRRRRR");
            person.setLastname("NNNNNN");
            person.getEmailAddresses().add("RRRRRR@yahoo.com");

            theEvent.getParticipants().add(person); // Adding person ref. to event for many to many relation

            session.save(theEvent);
            session.save(person);
            tx1.commit(); 

            System.out.println("Done...");

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            session.flush();
            session.close();
        }
    }
}

当我在上面运行示例时出现以下错误： INFO DefaultLoadEventListener:129 - 执行加载命令时出错 org.hibernate.exception.GenericJDBCException：无法初始化集合：[roseindia.tutorial.hibernate.Event.participants#1] 在 org.hibernate.exception.SQLStateConverter.handledNonSpecificException（SQLStateConverter.java:82）在 org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:70) 在 org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) 在 org.hibernate.loader.Loader.loadCollection(Loader.java:1351) 在 org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:101) 在 org.hibernate.persister.collection.AbstractCollectionPersister.initialize（AbstractCollectionPersister.java:484）在 org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection（DefaultInitializeCollectionEventListener.java:60）在 org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1346) 在 org.hibernate.collection.AbstractPersistentCollection.forceInitialization（AbstractPersistentCollection.java:269）在 org.hibernate.engine.PersistenceContext.initializeNonLazyCollections(PersistenceContext.java:745) 在 org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:208) 在 org.hibernate.loader.Loader.loadEntity(Loader.java:1255) 在 org.hibernate.loader.entity.EntityLoader.load(EntityLoader.java:139) 在 org.hibernate.loader.entity.EntityLoader.load(EntityLoader.java:124) 在 org.hibernate.persister.entity.BasicEntityPersister.load(BasicEntityPersister.java:2453) 在 org.hibernate.event.def.DefaultLoadEventListener.loadFromDatasource（DefaultLoadEventListener.java:387）在 org.hibernate.event.def.DefaultLoadEventListener.doLoad（DefaultLoadEventListener.java:368）在 org.hibernate.event.def.DefaultLoadEventListener.load（DefaultLoadEventListener.java:166）在 org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:140) 在 org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad（DefaultLoadEventListener.java:249）在 org.hibernate.event.def.DefaultLoadEventListener.onLoad（DefaultLoadEventListener.java:123）在 org.hibernate.impl.SessionImpl.get(SessionImpl.java:561) 在 org.hibernate.impl.SessionImpl.get(SessionImpl.java:556) 在roseindia.tutorial.hibernate.ManyToManyExample.main（ManyToManyExample.java:24）原因：java.sql.SQLException: [Microsoft][ODBC SQL Server Driver]Invalid Descriptor Index 在 sun.jdbc.odbc.JdbcOdbc.createSQLException（JdbcOdbc.java:6956）在 sun.jdbc.odbc.JdbcOdbc.standardError（JdbcOdbc.java:7113）在 sun.jdbc.odbc.JdbcOdbc.SQLGetDataDouble（JdbcOdbc.java:3656）在 sun.jdbc.odbc.JdbcOdbcResultSet.getDataDouble(JdbcOdbcResultSet.java:5574) 在 sun.jdbc.odbc.JdbcOdbcResultSet.getLong(JdbcOdbcResultSet.java:632) 在 sun.jdbc.odbc.JdbcOdbcResultSet.getLong(JdbcOdbcResultSet.java:650) 在 org.hibernate.type.LongType.get(LongType.java:26) 在 org.hibernate.type.NullableType.nullSafeGet(NullableType.java:77) 在 org.hibernate.type.NullableType.nullSafeGet(NullableType.java:68) 在 org.hibernate.persister.collection.AbstractCollectionPersister.readKey(AbstractCollectionPersister.java:612) 在 org.hibernate.loader.Loader.readCollectionElement(Loader.java:545) 在 org.hibernate.loader.Loader.readCollectionElements(Loader.java:344) 在 org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:299) 在 org.hibernate.loader.Loader.doQuery(Loader.java:384) 在 org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:203) 在 org.hibernate.loader.Loader.loadCollection(Loader.java:1344) ... 20 更多

我创建人员对象并通过使用 session.get(...) 获取事件来添加事件。对于多对多关系，在将每个对象添加到人员的事件列表之后，我正在做其他事情并将人员添加到事件对象的参与者列表中，这会引发异常。非常感谢任何有用或指导！

我使用 SQL Server 2008 作为数据库。

【问题讨论】：

标签： hibernate many-to-many associations

【解决方案1】：

尝试更改jdbc驱动包，可以使用jtds-1.2.jar，并将驱动类设置为net.sourceforge.jtds.jdbc.Driver

【讨论】：

非常感谢。我的问题得到了解决。我执行了以下步骤： 1. 从 url 下载 jtds-1.2.zip：sourceforge.net/projects/jtds/files。将“ntlmauth.dll”复制到我的 Windows/system32 文件夹中，并将 jtds-1.2.jar 放在我的路径中，它就像魔术一样工作。非常感谢您的快速帮助。问题出在 JDBC 驱动程序上。
我还必须将连接 URL 更改为："jdbc:jtds:sqlserver://:1433/" 非常感谢。
如果有人得到'未加载本机 SSPI 库。检查 java.library.path 系统属性。错误然后查看url：moonlit-software.com/logfaces/web/faq/s8.php