Hibernate - Como fazer update em tabela com chave estrangeira

Olá, tneho um projeto onde preciso alterar alguns dados de uma determinada tabela.
fiz todo o esquema de annotations na classe model da tabela, criei o método update corretamente e fiz a tela JSP também.

o problema é que quando clico para realizar o update aparece a seguinte Exception

org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: br.com.clearsalefilter.models.Usuario org.hibernate.engine.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:244) org.hibernate.type.EntityType.getIdentifier(EntityType.java:449) org.hibernate.type.ManyToOneType.nullSafeSet(ManyToOneType.java:132) org.hibernate.persister.entity.AbstractEntityPersister.dehydrate(AbstractEntityPersister.java:2168) org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2542) org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:2478) org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2805) org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:114) org.hibernate.engine.ActionQueue.execute(ActionQueue.java:268) org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:260) org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:180) org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51) org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206) org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:375) org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137) br.com.clearsalefilter.dao.RegrasDao.update(RegrasDao.java:38) br.com.clearsalefilter.actions.ValorAction.updateTipoItem(ValorAction.java:52) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) java.lang.reflect.Method.invoke(Unknown Source) com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:452) com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:291) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:254) com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:263) org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:133) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:270) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:190) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248) org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52) org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:498) org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91

O que eu entendi é que preciso realizar um tipo de update com as classe referenciadas pela cheve estreangeira. Só que pra eu fazer isso, preciso realizar novas buscas e tal. Queria saber se tem um jeito mais fácil, qualquer dica é bem vinda.

poste o metodo que vc implementou para podermos ajuda-lo.