Struts中bean:write tag读取数据的顺序问题

Mr. xiaodongx 问了我这个问题,没做实验不敢妄下结论,现写如下代码test一下

code block 1

public class TestAction extends Action {
 public ActionForward execute(
  ActionMapping mapping,
  ActionForm form,
  HttpServletRequest request,
  HttpServletResponse response)
  throws Exception {

  TestForm actionform = (TestForm) form;
  actionform.setP("p1");
  TestForm actionform2=new TestForm();
  actionform2.setP("p2");
  request.getSession().setAttribute("vo",actionform2);
  request.setAttribute("vo",actionform);

  return mapping.findForward("input");

 }

code blcok2

<bean:write name="vo" property="p"/>

此时页面显示p1

如果屏蔽掉绿色代码,页面显示p2

于是得出结论

<bean:write >标签先从request中读取数据,没有就从session中读,再没有就报错