jbpm3通过processDefinition.createProcessInstance()为什么能保存ProcessInstance之迷

数据库提交操作是在jbpmcontext.close()方法执行后,事务才提交的. close方法如下:

复制代码 public void close() {     log.debug("closing jbpmContext " + toString());     try {       if (services!=null) {         try {           autoSave();         } finally {           services.close();         }       }     } finally {       if (jbpmConfiguration!=null) {         jbpmConfiguration.jbpmContextClosed(this);       }     }   }

其中的autoSave()方法如下:

复制代码 void autoSave() {     if (autoSaveProcessInstances!=null) {       Iterator iter = autoSaveProcessInstances.iterator();       while (iter.hasNext()) {         ProcessInstance processInstance = (ProcessInstance) iter.next();         save(processInstance);         iter.remove();       }     }   }

一般人都认为是这里将processInstance保存到数据库.其实这里分2种情况,只有当以
jbpmContext.newProcessInstanceForUpdate(processName);方式启动流程时,才会执行这里的操作。
原因是autoSaveProcessInstances通过processDefinition.createProcessInstance()启动时没有值.
autoSave()方法里的循环操作,可以保存流程日志到数据库中.从另一个方面来讲只有以jbpmContext.newProcessInstanceForUpdate(processName);方式启动流程时,流程日志表才有数据.

那么我们的流程是通过processDefinition.createProcessInstance()方式启动的,为什么也能将processInstance保存到数据库呢.原因见
下面的堆栈信息.
EntityInsertAction.<init>(Serializable, Object[], Object, Object, EntityPersister, SessionImplementor) line: 34 
DefaultSaveOrUpdateEventListener(AbstractSaveEventListener).performSaveOrReplicate(Object, EntityKey, EntityPersister, boolean, Object, EventSource, boolean) line: 329 
DefaultSaveOrUpdateEventListener(AbstractSaveEventListener).performSave(Object, Serializable, EntityPersister, boolean, Object, EventSource, boolean) line: 181 
DefaultSaveOrUpdateEventListener(AbstractSaveEventListener).saveWithGeneratedId(Object, String, Object, EventSource, boolean) line: 121 
DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(SaveOrUpdateEvent) line: 187 
DefaultSaveOrUpdateEventListener.entityIsTransient(SaveOrUpdateEvent) line: 172 
DefaultSaveOrUpdateEventListener.performSaveOrUpdate(SaveOrUpdateEvent) line: 94 
DefaultSaveOrUpdateEventListener.onSaveOrUpdate(SaveOrUpdateEvent) line: 70 
SessionImpl.fireSaveOrUpdate(SaveOrUpdateEvent) line: 507 
SessionImpl.saveOrUpdate(String, Object) line: 499 
CascadingAction$1.cascade(EventSource, Object, String, Object, boolean) line: 218 
Cascade.cascadeToOne(Object, Type, CascadeStyle, Object, boolean) line: 268 
Cascade.cascadeAssociation(Object, Type, CascadeStyle, Object, boolean) line: 216 
Cascade.cascadeProperty(Object, Type, CascadeStyle, Object, boolean) line: 169 
Cascade.cascade(EntityPersister, Object, Object) line: 130 
DefaultSaveEventListener(AbstractSaveEventListener).cascadeBeforeSave(EventSource, EntityPersister, Object, Object) line: 431 
DefaultSaveEventListener(AbstractSaveEventListener).performSaveOrReplicate(Object, EntityKey, EntityPersister, boolean, Object, EventSource, boolean) line: 265 
DefaultSaveEventListener(AbstractSaveEventListener).performSave(Object, Serializable, EntityPersister, boolean, Object, EventSource, boolean) line: 181 
DefaultSaveEventListener(AbstractSaveEventListener).saveWithGeneratedId(Object, String, Object, EventSource, boolean) line: 121 
DefaultSaveEventListener(DefaultSaveOrUpdateEventListener).saveWithGeneratedOrRequestedId(SaveOrUpdateEvent) line: 187 
DefaultSaveEventListener.saveWithGeneratedOrRequestedId(SaveOrUpdateEvent) line: 33 
DefaultSaveEventListener(DefaultSaveOrUpdateEventListener).entityIsTransient(SaveOrUpdateEvent) line: 172 
DefaultSaveEventListener.performSaveOrUpdate(SaveOrUpdateEvent) line: 27 
DefaultSaveEventListener(DefaultSaveOrUpdateEventListener).onSaveOrUpdate(SaveOrUpdateEvent) line: 70 
SessionImpl.fireSave(SaveOrUpdateEvent) line: 535 
SessionImpl.save(String, Object) line: 523 
SessionImpl.save(Object) line: 519 
DbPersistenceService.assignId(Object) line: 330 
Services.assignId(Object) line: 257 
ProcessInstance.<init>(ProcessDefinition, Map, String) line: 137 
ProcessInstance.<init>(ProcessDefinition) line: 92 
ProcessDefinition.createProcessInstance() line: 125 
JpdlServiceImpl.createProcess(String) line: 50 
JpdlServiceImpl$$FastClassByCGLIB$$f5b03888.invoke(int, Object, Object[]) line: not available 
MethodProxy.invoke(Object, Object[]) line: 149 
Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint() line: 700 
Cglib2AopProxy$CglibMethodInvocation(ReflectiveMethodInvocation).proceed() line: 149 
TransactionInterceptor.invoke(MethodInvocation) line: 106 
Cglib2AopProxy$CglibMethodInvocation(ReflectiveMethodInvocation).proceed() line: 171 
ExposeInvocationInterceptor.invoke(MethodInvocation) line: 89 
Cglib2AopProxy$CglibMethodInvocation(ReflectiveMethodInvocation).proceed() line: 171 
Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Object, Method, Object[], MethodProxy) line: 635 
JpdlServiceImpl$$EnhancerByCGLIB$$ead8b30c.createProcess(String) line: not available 
JpdlProcessTest.testWorkflow() line: 11