Quoting Frank Zammetti <[EMAIL PROTECTED]>: > I don't see that behavior. Is there a setting in Tomcat to turn that > function on and off perhaps? None of my sessions survive a Tomcat restart, > so I've never had to deal with this. >
Tomcat will dump session objects which don't implement Serializable or are marked as such, but fail serialization for whatever reason. Make sure objects are serializable and the counter will persist across restarts (as long as the session hasn't already timed out). Jake > Frank > > > >From: "Radek Liebzeit" <[EMAIL PROTECTED]> > >Reply-To: "Tomcat Users List" <[EMAIL PROTECTED]> > >To: "'Tomcat Users List'" <[EMAIL PROTECTED]> > >Subject: RE: list active sessions. > >Date: Wed, 23 Jun 2004 07:51:08 +0200 > > > >Really nice. > > > >I am just wondering about one thing - about "persistent sessions". I > >have a session counter based on the SessionListeners. It is increased > >when some session is created and decreased when the session is > >destroyed. So, when I restart the Tomcat server some sessions are > >recreated but counter state doesn't. Therefore, after session timeout, > >the counter status is negative. > > > >It's not problem for me, it is enough for my purposes. I am just > >wondering how do you solve this behaviour? > > > >Radek > > > > > > > -----Original Message----- > > > From: Frank Zammetti [mailto:[EMAIL PROTECTED] > > > Sent: Monday, June 21, 2004 3:45 PM > > > To: [EMAIL PROTECTED] > > > Subject: RE: list active sessions. > > > > > > I spent a couple of days last week implementing just such a thing, so > >I > > > feel > > > qualified to answer :) > > > > > > There is no easy way to do it. There USED to be a SessionContext > >object > > > available in the servlet spec that would allow you to do a lot of cool > > > things with sessions, but it was removed as of spec 2.1 I think > >because > > > Sun > > > believed it to be a security risk. Unfortunately there was nothing > >added > > > to > > > take it's place. > > > > > > The way you have to do this, or at least one way (the only way I > >found) is > > > to track it yourself. > > > > > > First, I already had an AppConfig object that contains a static > >HashMap. > > > This has a bunch of config values for my app loaded from a config file > >at > > > startup. I then added an activeSessions HashMap to that class. > >Create a > > > similar class for yourself, along the lines of the following: > > > > > > import java.util.HashMap; > > > public class AppConfig { > > > private static HashMap activeUsers = null; > > > public static HashMap activeUsers() { > > > return activeUsers; > > > } > > > public static void setActiveUsers(HashMap inActiveUsers) { > > > activeUsers = inActiveUsers; > > > } > > > } > > > > > > Then, create a SessionListener something like the following: > > > > > > package com.mycompany.myapp; > > > import java.util.HashMap; > > > import javax.servlet.http.HttpSession; > > > import javax.servlet.http.HttpSessionEvent; > > > import javax.servlet.http.HttpSessionListener; > > > public class SessionListener implements HttpSessionListener { > > > public void sessionCreated(HttpSessionEvent se) { > > > HashMap activeUsers = (HashMap)AppConfig.getActiveUsers(); > > > synchronized (activeUsers) { > > > activeUsers.put(se.getSession().getId(), new HashMap()); > > > } > > > } > > > public void sessionDestroyed(HttpSessionEvent se) { > > > HashMap activeUsers = (HashMap)AppConfig.getActiveUsers(); > > > synchronized (appConfig) { > > > activeUsers.remove(se.getSession().getId()); > > > } > > > } > > > } > > > > > > Then just add the following to web.xml after your <servlet> section: > > > > > > <listener> > > > > ><listener-class>com.mycompany.myapp.SessionListener</listener-class> > > > </listener> > > > > > > Basically, every time a session is created, you'll get an entry in the > > > activeUsers HashMap keyed by sessionID, and the record will be removed > > > when > > > the session is destroyed. Further, what I do is that when my logon > >Action > > > is called, when the user is validated I add some information for that > >user > > > into the HashMap (first name, last name, logon time, etc). This > >allows me > > > to have a pretty nice little tracking display in my app. > > > > > > The one problem you run into with this is that if the user just closes > >the > > > browser window rather than using your nice logout function, the > >session > > > lingers until the timeout period elapses. I didn't like that! My app > >is > > > frames-based, and I already had one hidden frame, so I added the > >following > > > to the <body> tag of that frame's source document: > > > > > > onUnload="openLogoffPopup();" > > > > > > ... and then the openLogoffPopup() function: > > > > > > function openLogoffPopup() { > > > windowHandle = window.open("", "", > >"width=200,height=1,top=1,left=1"); > > > str = "<" + "html><" + "head><" + "title><" + "/title><" + > >"/head>"; > > > str += "<" + "body > > > onLoad=\"window.location='<%=request.getContextPath() > > > + "/app/logoff.app"%>';\">"; > > > str += "<" + "table width=\"100%\" height=\"100%\" border=\"0\">"; > > > str += "<" + "tr><" + "td align=\"center\" valign=\"middle\">"; > > > str += "<" + "span > > > style=\"color:#000000;font-family:arial;font-size:11pt;font- > > > weight:bold;\">"; > > > str += "Logging out of application...<" + "/span"; > > > str += "<" + "/td><" + "/tr>"; > > > str += "<" + "/table>"; > > > str += "<" + "/body><" + "/html>"; > > > windowHandle.document.write(str); > > > windowHandle.document.close(); > > > } > > > > > > That calls the logoff Action whcih does not much more than > > > session.invalidate(). This works well in IE, I do not know if it is > > > cross-browser though (not a concern for my company). It should work > >fine > > > to > > > add this to all your JSP's, assuming your app isn't frame-based, I > >think > > > it'll work just the same. But, maybe you can live with the session > > > lingering if the window is closed anyway. It's probably not a big > >concern > > > if the timeout period is short enough, but you need to recognize that > >you > > > may see more than one session per user for a few minutes if they log > >on > > > again. > > > > > > Hope that helps! > > > > > > Frank > > > > > > > > > >From: Alex <[EMAIL PROTECTED]> > > > >Reply-To: "Tomcat Users List" <[EMAIL PROTECTED]> > > > >To: Tomcat Users List <[EMAIL PROTECTED]> > > > >Subject: list active sessions. > > > >Date: Mon, 21 Jun 2004 08:52:42 -0400 (EDT) > > > > > > > > > > > >Is there a way to list all sessions which are currently active for > >the > > > >webapp which would be calling for such a list? > > > > > > > > > > > >--------------------------------------------------------------------- > > > >To unsubscribe, e-mail: [EMAIL PROTECTED] > > > >For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > > > _________________________________________________________________ > > > Is your PC infected? Get a FREE online computer virus scan from > >McAfeeR > > > Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963 > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > > > > > >--------------------------------------------------------------------- > >To unsubscribe, e-mail: [EMAIL PROTECTED] > >For additional commands, e-mail: [EMAIL PROTECTED] > > > > _________________________________________________________________ > >From �will you?� to �I do,� MSN Life Events is your resource for Getting > Married. http://lifeevents.msn.com/category.aspx?cid=married > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
