hibernate报错:an assertion failure occured (this may indicate a bug in Hibernate
实在是对这个错误没辙了，网上也查了资料但是和我的情况也不符合，各位帮帮忙哈！
先贴错误

11:17:22,796 ERROR org.hibernate.AssertionFailure:45 - an assertion failure occured (this may indicate a bug in Hibernate, but is more likely due to unsafe use of the session)

org.hibernate.AssertionFailure: null id in com.sykjw.entity.Goods entry (don't flush the Session after an exception occurs)

	at org.hibernate.event.def.DefaultFlushEntityEventListener.checkId(DefaultFlushEntityEventListener.java:78)

	at org.hibernate.event.def.DefaultFlushEntityEventListener.getValues(DefaultFlushEntityEventListener.java:187)

	at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:143)

	at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:219)

	at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:99)

	at org.hibernate.event.def.DefaultAutoFlushEventListener.onAutoFlush(DefaultAutoFlushEventListener.java:58)

	at org.hibernate.impl.SessionImpl.autoFlushIfRequired(SessionImpl.java:997)

	at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1142)

	at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)

	at com.sykjw.dao.impl.CategoryDAOImpl.findByName(CategoryDAOImpl.java:123)

	at com.sykjw.service.CategoryService.findByName(CategoryService.java:64)

	at com.sykjw.action.CategoryAction.findKfcAndBskCategory(CategoryAction.java:86)

	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 com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:440)

	at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:279)

	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)

	at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:163)

	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)

	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)

	at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:249)

	at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)

	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)

	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)

	at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)

	at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)

	at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)

	at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)

	at com.opensymphony.xwork2.DefaultActionInvocation.invok