Hi! It used to be a render parameter, but was changed due to this: https://issues.apache.org/jira/browse/WW-2052
Nils-H On Sun, May 22, 2011 at 8:02 PM, huang.mi...@gmail.com <huang.mi...@gmail.com> wrote: > Hi Pyerson, > I'm also using portlet2 plugin, which seems derived from struts portlet > plugin, brings same method to handle directRender from action phase. Thus it > has same problems :). But since the source is from struts bundled portlet > plugin, I'd better discuss this issue here. > First let me clear the ACTION word. It's both used in struts and portlet > specification, referencing totally different things. I'll use "portlet > action phase" and "struts action" here to avoid confusing, although it's > cumbersome. > First some background information about this issue: > A portlet action phase request is mapped to a struts action request by the > struts portlet plugin. Due to the portlet JSR definition, in action phase > process no output is rendered. Instead a follow on render phase request is > used to take the actual render responsible. However the struts action can > define a JSP render result. In this case, the struts action's result process > actually not do render process, but save the render JSP location to the > session map and finished the result process immediately. The actual JSP > render process is taken place by the follow on portlet render phase request, > which is mapping to the struts portlet plugin internal defined > "directRender" action. The directRender action load the previously saved JSP > location and do the actual JSP render as it's result. Thus the portlet > render phase response get JSP render output AS IF it is rendered out by the > result defined in the struts action. See the in question source code which > is doing the process described here: > > org.apache.struts2.portlet.result.PortletResult.executeActionResult(String, > ActionInvocation) > org.apache.struts2.portlet.dispatcher.DirectRenderFromEventAction, > > The problem is: > The session is shared by all requests in the same session, in a > multi-threaded concurrent executing environment. This may cause > indeterminable problems on a heavy load site. > Suppose 2 request(Request A and Request B) from same session come to the > portal at nearly same time. The process sequence of the 2 request may like > this: > 1. Request A get action phase process, and its struts action (action A) > result process stored the JSP location (a.jsp) to the session map. > 2. Request B get action phase process, and its struts action (action B) > result process stored the JSP location (b.jsp) to the session map, which > overwrites JSP location (a.jsp) set by action A. > 3. Request A get render phase process, and the renderDirect action get > incorrect JSP location b.jsp. Request A will render the wrong JSP result. > 4. Request B get render phase process, and the renderDirect action get > correct JSP location b.jsp, and render the JSP result correctly. > This problem may not easy to reproduce during the development lifecycle, > except you use an automatic load testing tool to test it. But when the > system is deployed to the production environment and the site load get > heavy, the possibility to run into the issue case get higher. > Hope I have described the issue clearly and feel free to place a note on > what I have missing. > > Best Regards, > Miles. > > > 在 2011-05-21Sat的 20:54 -0400，Jason Pyeron写道： > > I am having a little trouble following what you are saying. Do you have an > example that might better say the issue. > > I am currently using the portlet2 plugin as well. > > ________________________________ > > From: Miles Huang [mailto:miles.hu...@surwing.com] > Sent: Saturday, May 21, 2011 11:52 > To: dev@struts.apache.org > Subject: Portlet plugin renderDirect location transfer via session may > has concurrent issue > > > Hi, > I'm using struts2 portlet plugin for a portlet project recently. > In some case, I have to use renderDirect action to render JSP result > directly from an portlet action phase request. > When I'm examining the PortletResult source code, surprisingly I found > the result location is transfer to the renderDirect action via session map > instead of render parameter. > Is there any special reason to do this? I think current via session > method may result current issue: Suppose multiple client in same session > (normally multiple opened browser windows) send action phase request to the > portlet concurrently, the result location of a action phase request may > override > by another request. > Any one can confirm on this? > > Thanks, > Miles. > > -- > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- > - - > - Jason Pyeron PD Inc. http://www.pdinc.us - > - Principal Consultant 10 West 24th Street #100 - > - +1 (443) 269-1555 x333 Baltimore, Maryland 21218 - > - - > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- > This message is copyright PD Inc, subject to license 20080407P00. > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@struts.apache.org > For additional commands, e-mail: dev-h...@struts.apache.org > > > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@struts.apache.org For additional commands, e-mail: dev-h...@struts.apache.org
