这是审核方法

public ActionForward approve(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
int leaveId = Integer.parseInt(request.getParameter("leaveId"));
int taskInstanceId = Integer.parseInt(request
.getParameter("taskInstanceId"));
JbpmContext context = JbpmConfiguration.getInstance()
.createJbpmContext();

// 加载请假条
Leave leave = (Leave) context.getSession().load(Leave.class, leaveId);

ProcessInstance processInstance = context.getProcessInstance(leave
.getProcessInstanceId());

TaskMgmtSession taskMgmtSession = context.getTaskMgmtSession();

TaskInstance taskInstance = taskMgmtSession
.loadTaskInstance(taskInstanceId);

if (taskInstance.getStart() == null) {
// 没开始的话则开始，即向start开始时间字段填入数据
taskInstance.start("manager2");
}

taskInstance.end();

// 触发流程往下走
// processInstance.getRootToken().signal();

// 当前结点名称
System.out.println(processInstance.getRootToken().getNode().getName());
response.sendRedirect("manager.do?method=viewTasks");
return null;
}



采用的是否泳道，我发现当我执行完这个方法时，数据库的taskInstance表并没有变化，start,end字段都没有值。。。      大家看看是怎么回事啊