Redirect or Forward

anweixiao

如果页面/bb/a.jsp
假设我们有一个Filter的配置为:/bb/*,其中有一段代码为
if( need condition)
   request.setAttribute("errormessage","The Error info.");
   response.sendRedirect(ERROR_FOR_SOME_)
/if
在出错的页面不会看到预期的错误提示,
error_page.jsp
  <c:out value="${errormessage}"></c:out>
Of course we cannot see any error info here,because of using the "sendRedirect"!!!
注意：redirect!!!修改为:
  request.getRequestDispatcher(ERROR_FOR_SOME_).forward(request,response);
问题可解决
如果又在/bb/a.jsp页面中使用了:
<jsp:forward page="/some.jsp"/>
Error：Cannot forward after response has been committed