Hibernate多对多关系：如何修复org.Hibernate.exception.genericjdbception:无法初始化集合异常？
我使用Hibernate站点上的Hibernate_reference.pdf使用Hibernate多对多关联。我使用的实体与文档中描述的实体Event.java和Person.java相同 我看到许多人面临“无法初始化集合异常”的问题，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：Hibernate多对多关系：如何修复org.Hibernate.exception.genericjdbception:无法初始化集合异常？,hibernate,many-to-many,associations,Hibernate,Many To Many,Associations,我使用Hibernate站点上的Hibernate_reference.pdf使用Hibernate多对多关联。我使用的实体与文档中描述的实体Event.java和Person.java相同 我看到许多人面临“无法初始化集合异常”的问题，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"?> <!DO
<?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>
我使用SQL Server 2008作为数据库。尝试更改jdbc驱动程序包，您可以使用jtds-1.2.jar，并将驱动程序类设置为net.sourceforge.jtds.jdbc.driver非常感谢。我的问题解决了。我执行了以下步骤：1。已从url下载jtds-1.2.zip:。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，效果非常神奇。非常感谢您的快速帮助。问题是JDBC驱动程序。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:
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;
}
}
<?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>
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() {
}
}
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();
}
}
}