两个类，Template和 Parameter： one-to-many
test代码：
QueryTemplate template = new QueryTemplate();
template.setLabel("Test template label");
template.setName("Test template name");
QueryEngineDAO.save(template);
save（）中代码是： Transaction tan = session.beginTransaction();
session.save(template);
session.flush();
tan.commit();
如果Template中如果定义： private Collection queyParameters ＝ new ArrayList(); 则报错：
Enter com.hp.dragon.util.QueryEngineDAO save() and the obj's class is: com.hp.dragon.model.QueryTemplate
Exception in thread "main" org.hibernate.PropertyAccessException: IllegalArgumentException occurred calling getter of com.hp.dragon.model.TemplateParameter.id
at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:119)
at org.hibernate.tuple.AbstractTuplizer.getIdentifier(AbstractTuplizer.java:103)
at org.hibernate.persister.entity.BasicEntityPersister.getIdentifier(BasicEntityPersister.java:2944)
at org.hibernate.persister.entity.BasicEntityPersister.isTransient(BasicEntityPersister.java:2705)
at org.hibernate.engine.ForeignKeys.isTransient(ForeignKeys.java:181)
at org.hibernate.event.def.AbstractSaveEventListener.getEntityState(AbstractSaveEventListener.java:409)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:82)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:69)
at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:468)
at org.hibernate.engine.Cascades$5.cascade(Cascades.java:154)
at org.hibernate.engine.Cascades.cascadeAssociation(Cascades.java:771)
at org.hibernate.engine.Cascades.cascade(Cascades.java:720)
at org.hibernate.engine.Cascades.cascade(Cascades.java:847)
at org.hibernate.event.def.AbstractSaveEventListener.cascadeBeforeSave(AbstractSaveEventListener.java:332)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:214)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:160)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:108)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:184)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:173)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:69)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:481)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:476)
at com.hp.dragon.util.QueryEngineDAO.save(QueryEngineDAO.java:54)
at com.hp.dragon.test.TestTool.initQuery(TestTool.java:41)
at com.hp.siu.collector.datastore.riss.test.TestThread.run(TestThread.java:27)
at com.hp.dragon.test.TestRissQueryEngine.main(TestRissQueryEngine.java:17)
Caused by: java.lang.IllegalArgumentException: object is not an instance of declaring class
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:105)
... 27 more
如果改为private Collection queyParameters－就是不要初始化这个collectiion，则OK。
mapping文件是用xdoclet生成的：
<many-to-one
name="templateParameters"
class="com.hp.dragon.model.TemplateParameter"
column="SEARCH_TYPE_ID"
cascade="none"
>
</many-to-one>