我有一个spring mvc项目。对于视图，我首先使用jsp并且它工作正常，但后来我想使用velocity并得到异常。除了语法之外，两个视图都是相似的。我无法理解它为什么会发生。那是我的jsp：
<form:form action="updateDepartament" modelAttribute="editDepartament" method="POST">
<table>
<tr>
<td>Id:</td>
<td><form:input path="departamentId" readonly="true"/></td>
</tr>
<tr>
<td><spring:message code="label.title"/></td>
<td><form:input path="title"/></td>
<td><form:errors path="title"/></td>
</tr>
</table>
<input type="submit" value="submit">
<c:if test="${! empty editDepartament.depart_Employeers}">
<table>
<th>Id</th>
<th><spring:message code="label.firstName"/></th>
<th><spring:message code="label.lastName"/></th>
<th><spring:message code="label.salary"/></th>
<th><spring:message code="label.birthdate"/></th>
<th><spring:message code="label.active"/></th>
<tr>
<c:forEach var="empl" items="${editDepartament.depart_Employeers}" varStatus="status">
<tr>
<td><form:input path="depart_Employeers[${status.index}].id" readonly="true"/></td>
<td><form:input path="depart_Employeers[${status.index}].firstName" readonly="true"/></td>
<td><form:input path="depart_Employeers[${status.index}].lastName" readonly="true"/></td>
<td><form:input path="depart_Employeers[${status.index}].salary" readonly="true"/></td>
<td><form:input path="depart_Employeers[${status.index}].birthday" readonly="true"/></td>
<td><form:input path="depart_Employeers[${status.index}].active" readonly="true"/></td>
<td><a href="deleteEmployee/${empl.id}"><spring:message code="label.delete"/></a></td>
</tr>
</c:forEach>
</tr>
</table>
</c:if>
</form:form>
这是我的速度模板：
<form action="updateDepartament" method="POST">
#springBind("editDepartament")
<table>
<tr>
<td>Id:</td>
<td>#springFormInput("editDepartament.departamentId" 'readonly="true"')</td>
</tr>
<tr>
<td><spring:message code="label.title"/></td>
<td>#springFormInput("editDepartament.title" "")</td>
<td>#springShowErrors("" "")</td>
</tr>
</table>
<input type="submit" value="submit">
#if(!$editDepartament.depart_Employeers.isEmpty())
<table>
<th>Id</th>
<th>#springMessage("label.firstName")</th>
<th>#springMessage("label.lastName")</th>
<th>#springMessage("label.salary")</th>
<th>#springMessage("label.birthdate")</th>
<th>#springMessage("label.active")</th>
<tr>
#foreach($empl in $editDepartament.depart_Employeers)
<tr>
<td>#springFormInput("editDepartament.depart_Employeers[$velocityCount].id" 'readonly="true"')</td>
<td>#springFormInput("editDepartament.depart_Employeers[$velocityCount].firstName" 'readonly="true"') </td>
<td>#springFormInput("editDepartament.depart_Employeers[$velocityCount].lastName" 'readonly="true"')</td>
<td>#springFormInput("editDepartament.depart_Employeers[$velocityCount].salary" 'readonly="true"')</td>
<td>#springFormInput("editDepartament.depart_Employeers[$velocityCount].birthday" 'readonly="true"')</td>
<td>#springFormInput("editDepartament.depart_Employeers[$velocityCount].active" 'readonly="true"')</td>
<td><a href="deleteEmployee/${empl.id}">#springMessage("label.delete")</a></td>
</tr>
#end
</tr>
</table>
#end
</form>
更改标题后发生异常：
HTTP Status 500 -
--------------------------------------------------------------------------------
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.dao.InvalidDataAccessApiUsageException: object references an unsaved transient instance - save the transient instance before flushing: com.mycompany.employeers.domain.Employee; nested exception is org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.mycompany.employeers.domain.Employee
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:681)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:585)
javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:369)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:100)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:119)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:35)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:168)
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
root cause
org.springframework.dao.InvalidDataAccessApiUsageException: object references an unsaved transient instance - save the transient instance before flushing: com.mycompany.employeers.domain.Employee; nested exception is org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.mycompany.employeers.domain.Employee
org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:654)
org.springframework.orm.hibernate3.HibernateTransactionManager.convertHibernateAccessException(HibernateTransactionManager.java:793)
org.springframework.orm.hibernate3.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:664)
org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:754)
org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:723)
org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:393)
org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:120)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
$Proxy723.editDepartament(Unknown Source)
com.mycompany.employeers.web.EmployeesController.updateDepartament(EmployeesController.java:204)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:436)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:424)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:669)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:585)
javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:369)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:100)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:119)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:35)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:168)
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
root cause
org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.mycompany.employeers.domain.Employee
org.hibernate.engine.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:219)
org.hibernate.type.EntityType.getIdentifier(EntityType.java:397)
org.hibernate.type.ManyToOneType.nullSafeSet(ManyToOneType.java:78)
org.hibernate.persister.collection.AbstractCollectionPersister.writeElement(AbstractCollectionPersister.java:755)
org.hibernate.persister.collection.AbstractCollectionPersister.recreate(AbstractCollectionPersister.java:1143)
org.hibernate.action.CollectionRecreateAction.execute(CollectionRecreateAction.java:39)
org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:171)
org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298)
org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:338)
org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
org.springframework.orm.hibernate3.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:656)
org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:754)
org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:723)
org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:393)
org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:120)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
$Proxy723.editDepartament(Unknown Source)
com.mycompany.employeers.web.EmployeesController.updateDepartament(EmployeesController.java:204)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:436)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:424)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:669)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:585)
javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:369)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:100)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:119)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:35)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:168)
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
负责控制器的这个视图部分：
@RequestMapping(value="/updateDepartament", method= RequestMethod.POST)
public String updateDepartament(@ModelAttribute("editDepartament")Departament dep, BindingResult result){
departamentValidator.validate(dep, result);
if(result.hasErrors()){
return "editDepartament";
}
service.editDepartament(dep);
return "redirect:/listDepartaments";
}
也许有人知道如何解决这个问题，可以解释一下吗？
答案 0 :(得分：1)
仔细查看异常，然后您将看到渲染时不会发生异常，但会从service.editDepartament(dep);方法调用EmployeesController.updateDepartament。
....
com.mycompany.employeers.web.EmployeesController.updateDepartament(EmployeesController.java:204)
....
对我而言，Departament dep引用的实体之一看起来与您的Hibernate实体管理器分离。 - 但是我不能从您发布的有限数量的代码中提供更多详细信息。
总结一下：问题在请求处理中的某个地方（与hibernate相关），但我强烈怀疑它与视图有关（除了有一些过滤器（如视图中的开放实体管理器），它只是触发了渲染jsps但不渲染速度模板的请求。
答案 1 :(得分：0)
我找到了解决方案。我没有添加到我的实体Departament cascadeType.All：
@OneToMany(fetch= FetchType.EAGER,cascade= CascadeType.ALL)
@JoinColumn(name="DEPARTAMENTID")
private List<Employee> depart_Employeers;
现在它可以工作，但我有点困惑..为什么应用程序使用jsp而没有定义cascadeType？