Hibernate 出现attempted to assign id from null one-to-one property
我有三个表,表1 Item (Itemid listprice unitcost supplier attrl)
表2 Inventory (Itemid qty)
一对一的关系.
Inventory.xml中的数据
<id name="itemid" type="java.lang.String">
<column name="itemid" length="10" />
<generator class="foreign">
<param name="property">item</param>
</generator>
</id>
<one-to-one name="item" class="com.ymyjsq.vo.Item"
constrained="true" />
Item.xml中的数据
<id name="itemid" type="java.lang.String">
<column name="itemid" length="10" />
<generator class="assigned" />
</id>
<one-to-one name="inventory" class="com.ymyjsq.vo.Inventory"
cascade="all" />
保存时出现错误
17:22:09,281 ERROR product:52 - save failed
org.hibernate.id.IdentifierGenerationException: attempted to assign id from null one-to-one property: item
at org.hibernate.id.ForeignGenerator.generate(ForeignGenerator.java:44)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:91)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:186)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:175)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:530)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:518)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:514)
at com.ymyjsq.dao.product.addInventory(product.java:47)
at com.ymyjsq.dao.product.addProduct(product.java:28)
at com.ymyjsq.admin.biz.ProductsBiz.addProducts(ProductsBiz.java:16)
at com.ymyjsq.admin.struts.action.productsAction.addProduct(productsAction.java:79)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:270)
at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:187)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:270)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:191)
at com.ymyjsq.Filter.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:45)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:220)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:191)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:227)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:211)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:866)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:705)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1486)
at java.lang.Thread.run(Thread.java:619)
但是Item表保存成功,请各位给予帮助。谢谢大家