Hibernate 使用动态模型(Map)时报 org.hibernate.LazyInitializationException错误

以下是配置信息：
 <class name="Employee" table="Employee">
        <id name="employeeId" column="EID">
            <generator class="identity" />
        </id>
        <property name="name" type="string" column="EmployeeName" />
        <many-to-one name="depart" column="Depart_Id"></many-to-one>
    </class><class name="Depart" table="Depart">
        <id name="departId" column="departId">
            <generator class="identity" />
        </id>
        <property name="name" type="string" column="departName" />
        
        <set name="emps" cascade="save-update" inverse="true">
         <key column="Depart_Id"></key>
         <one-to-many class="Employee"/>
        </set>
    </class>这里是Java代码
Session session=HibernateUtil.getSession(); Transaction tran=session.beginTransaction();

Depart depart=new Depart();
depart.setName("开发部门");

Set<Employee> emps=new HashSet<Employee>();
Employee e1=new Employee();
e1.setName("张三");
emps.add(e1);
e1.setDepart(depart);

Employee e2=new Employee();
e2.setName("李四");
emps.add(e2);
e2.setDepart(depart);

depart.setEmps(emps);

session.save(depart);
session.save(e1);
session.save(e2);

tran.commit();
Session sessModel=session.getSession(EntityMode.MAP);
Map m=(Map)sessModel.get(Depart.class, 1);
System.out.println("departId:"+m.get("departId"));//这两句能够正常的打印值
System.out.println("name:"+m.get("name"));

Set s=(Set)m.get("emps");
Iterator it=s.iterator();//程序运行到这里就报错

//.....其它操作

session.close();
以下是打印信息:
Hibernate: insert into Depart (departName) values (?)
Hibernate: insert into Employee (EmployeeName, Depart_Id) values (?, ?)
Hibernate: insert into Employee (EmployeeName, Depart_Id) values (?, ?)
Hibernate: select depart0_.departId as departId1_0_, depart0_.departName as departName1_0_ from Depart depart0_ where depart0_.departId=?
departId:1
name:开发部门
Hibernate: select emps0_.Depart_Id as Depart3_1_, emps0_.EID as EID1_, emps0_.EID as EID2_0_, emps0_.EmployeeName as Employee2_2_0_, emps0_.Depart_Id as Depart3_2_0_ from Employee emps0_ where emps0_.Depart_Id=?
Exception in thread "main" org.hibernate.LazyInitializationException: illegal access to loading collection
at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:363)
at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:108)
at org.hibernate.collection.PersistentSet.hashCode(PersistentSet.java:434)
at java.util.HashMap$Entry.hashCode(Unknown Source)
at java.util.AbstractMap.hashCode(Unknown Source)
at java.util.HashMap$Entry.hashCode(Unknown Source)
at java.util.AbstractMap.hashCode(Unknown Source)
at java.util.HashMap.put(Unknown Source)
at java.util.HashSet.add(Unknown Source)
at java.util.AbstractCollection.addAll(Unknown Source)
at org.hibernate.collection.PersistentSet.endRead(PersistentSet.java:352)
at org.hibernate.engine.loading.CollectionLoadContext.endLoadingCollection(CollectionLoadContext.java:260)
at org.hibernate.engine.loading.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:245)
at org.hibernate.engine.loading.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:218)
at org.hibernate.loader.Loader.endCollectionLoad(Loader.java:900)
at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:888)
at org.hibernate.loader.Loader.doQuery(Loader.java:752)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
at org.hibernate.loader.Loader.loadCollection(Loader.java:2019)
at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:59)
at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:587)
at org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:83)
at org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1744)
at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:366)
at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:108)
at org.hibernate.collection.PersistentSet.iterator(PersistentSet.java:186)
at org.ing.test.Test.main(Test.java:156)
试了好多种办法，它都是报这个错误，请高手们帮忙