出错: 这个ClassCast Exception 是怎么回事?

软件环境: linux , Hibernate2.0 , Oracle数据库, 驱动:oracle.jdbc.driver.OracleDriver

配置文件:hibernate.connection.driver_class = oracle.jdbc.driver.OracleDriver
hibernate.connection.url = jdbc:oracle:thin:@saturn.dragontec:1521:qjfdb
hibernate.connection.username = system
hibernate.connection.password = manager
hibernate.dialect = net.sf.hibernate.dialect.OracleDialect
hibernate.show_sql true

对象关系: B_husband , B_wife,B_ child, husband和wife是一对一的关系, husband 和
child 是一对多的关系.

public class B_husband {
private int id;
private String name;
private List childs;
private B_wife wife;

public B_husband() {
}

public void setId(int t){
id = t;
}

public int getId(){
return id;
}

public void setName(String t){
name = t;
}

public String getName(){
return name;
}

public void setChilds(List t){
childs = t;
}

public List getChilds(){
return childs;
}

public void setWife(B_wife t){
wife = t;
}

public B_wife getWife(){
return wife;
}

}

/******************************************************/
public class B_wife {
private int id;
private String name;

public B_wife() {
}

public void setId(int t) {
id = t;
}

public int getId() {
return id;
}

public void setName(String t) {
name = t;
}

public String getName() {
return name;
}

}
/*********************************************************/

public class B_child {
private int id;
private String name;
private char sex;
private B_husband b_husband;

public B_child() {
}

public void setId(int t){
id = t;
}

public int getId(){
return id;
}

public void setName(String t){
name = t;
}

public String getName(){
return name;
}

public void setSex(char t){
sex = t;
}

public char getSex(){
return sex;
}

public void setB_husband(B_husband t){
b_husband = t;
}

public B_husband getB_husband(){
return b_husband;
}

}

/****************************************************/
以下是处理并出错的class:
public class Test {
private SessionFactory _sessions;

public Test() {
}
public static void main(String[] args) {
Test test1 = new Test();
try{
test1.configure();
test1.exportTables();

/******************************************************************/
B_wife wife = test1.createWife("wife");
B_husband husband = test1.createHusband("husband", wife);
test1.createChild("child", 'm', husband);


} catch(Exception e){
e.printStackTrace();
}
}

public void configure() throws HibernateException {
_sessions = new Configuration()
.addClass(B_husband.class)
.addClass(B_child.class)
.addClass(B_wife.class)
.buildSessionFactory();
}

public void exportTables() throws HibernateException {
Configuration cfg = new Configuration()
.addClass(B_husband.class)
.addClass(B_child.class)
.addClass(B_wife.class);

new SchemaExport(cfg).create(true, true);
}

public B_husband createHusband(String name, B_wife wife) throws HibernateException{
B_husband husband = new B_husband();
husband.setName(name);
husband.setChilds( new ArrayList() );
husband.setWife( wife );

Session session = _sessions.openSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
session.save(husband);
tx.commit();
}
catch (HibernateException he) {
if (tx!=null) tx.rollback();
throw he;
}
finally {
session.close();
}

return husband;
}

public B_child createChild(String name, char t, B_husband husband) throws HibernateException{
B_child child = new B_child();
child.setName( name );
child.setSex( t );
child.setB_husband( husband );
husband.getChilds().add( child );

Session session = _sessions.openSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
session.save(child);
tx.commit();
}
catch (HibernateException he) {
if (tx!=null) tx.rollback();
throw he;
}
finally {
session.close();
}

return child;
}

public B_wife createWife(String name) throws HibernateException{
B_wife wife = new B_wife();

wife.setName( name );

Session session = _sessions.openSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
session.save(wife);
tx.commit();
}
catch (HibernateException he) {
if (tx!=null) tx.rollback();
throw he;
}
finally {
session.close();
}

return wife;
}

}

出错信息如下:
java.lang.ClassCastException
at net.sf.hibernate.type.SetType.wrap(SetType.java:27)
at net.sf.hibernate.impl.SessionImpl.wrap(SessionImpl.java:2496)
at net.sf.hibernate.impl.SessionImpl.wrap(SessionImpl.java:2436)
at net.sf.hibernate.impl.SessionImpl.doSave(SessionImpl.java:723)
at net.sf.hibernate.impl.SessionImpl.save(SessionImpl.java:620)
at test.Test.createHusband(Test.java:75)
at test.Test.main(Test.java:39)

配置xml如下:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>

    <class
        name="test.B_husband"
        table="B_HUSBANDS"
        proxy="test.B_husband">

        <id
            name="id"
            column="husband_id">

            <generator class="assigned"/>

        </id>

        <property
            name="name"
            column="name"
            not-null="true"
            unique="true"/>

<one-to-one name="wife" class="test.B_wife" constrained="true"
cascade="all"/>

<set
            name="childs"
            inverse="true"
            lazy="true"
            order-by="child_id"
            cascade="all">
            <key column="husband_id"/>
            <one-to-many class="test.B_child"/>
        </set>
    </class>
</hibernate-mapping>

/*******************************************/
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>
  <class name="test.B_wife" table="B_WIFES">

      <id name="id" column="wife_id">
        <generator class="native"/>
      </id>
      <property name="name"/>

</class>
</hibernate-mapping>

/***************************************************/
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>

    <class
        name="test.B_child"
        table="B_CHILDS"
        dynamic-update="true">

        <id
            name="id"
            column="child_id">

            <generator class="native"/>

        </id>

        <property
            name="name"
            column="name"
            not-null="true"/>

        <property
            name="sex"
            column="SEX"
            not-null="true"/>

        <many-to-one
            name="b_husband"
            column="husband_id"
            not-null="true"/>

    </class>

</hibernate-mapping>


哪位老大帮帮忙告诉我阿, 很急! 在线等, 谢了!

不好意思, 版主, 怎么对代码code格式化阿, 我选择那段并且用了哪个code按钮, 可是好像没有用阿.

如图

B_wife wife = test1.createWife("wife");
B_husband husband = test1.createHusband("husband", wife);

这里写错了。
应该是：
B_wife wife = (B_wife)test1.createWife("wife");
....

我是用了哪个按钮, 而且还多点了两次, 就怕没用,怎么回事阿?

不好意思阿, 刚刚改了按照版主的用法, 不过还是一样的, 怎么回事阿?   wife表插入了一条记录, husband出了一样的错, 昨天就是这样的. 还是要麻烦版主了.
java.lang.ClassCastException
at net.sf.hibernate.type.SetType.wrap(SetType.java:27)
at net.sf.hibernate.impl.SessionImpl.wrap(SessionImpl.java:2496)
at net.sf.hibernate.impl.SessionImpl.wrap(SessionImpl.java:2436)
at net.sf.hibernate.impl.SessionImpl.doSave(SessionImpl.java:723)
at net.sf.hibernate.impl.SessionImpl.save(SessionImpl.java:620)
at test.Test.createHusband(Test.java:77)
at test.Test.main(Test.java:38)

private List childs; 

<set 
name="childs" 
inverse="true" 
lazy="true" 
order-by="child_id" 
cascade="all"> 
<key column="husband_id"/> 
<one-to-many class="test.B_child"/> 
</set> 

List,set?

谢谢, 我改过了之后可以正常运行了. 
如果使用Set  Class 在 .hbm.xml 中要用 &lt;Set/&gt; ,
如果使用List Class 在 .hbm.xml 中要用 &lt;Bag/&gt; ,
虽然不知道为什么, 我会再仔细看看文档的,
刚刚用Hibernate 两天, 所以有点不知道该怎么调试, 而且它的Exception信息很奇怪, 都是他内部的类出错, 我又不能跟踪进去看, 不知道这种情况下有什么办法可以较快的调试吗?

有必要再多说两句, 我之所以会犯这个错误, 是 因为我在只用
两个Class测试一对多的时候, List Class 使用 &lt;set/&gt;元素是可以正常存取的, 所以在加了一个一对一之后我就没有在意这个是否匹配, 还是不知道为什么会出现这样的情况, 可能是
Hibernate内部的处理多个Class的时候, 没有把这个情况处理掉,提醒一下, 还有谢谢解答的朋友.