You are 100% correct. Luckily this approach is actually very simple in implementation, but if used, the handle to the shared utility object should be provided by a factory method and the utility object itself should conform to an interface (in each application). Calling application objects should use this interface and factory method to get/store objects. That way a more robust implementation can be swapped in "under the covers" without affecting the calling applications.
A more robust implemenation would be to store the shared session data in a common database, if the applications are indeed using the same database. This has its own implications, however... If they are not using a common database, then an EJB layer or perhaps XML through sockets or over HTTP between applications would be required. I guess you would call the latter a "web service" (why not). :) peace, Joe Barefoot > -----Original Message----- > From: Ralph Roland [mailto:[EMAIL PROTECTED]] > Sent: Thursday, June 13, 2002 2:45 PM > To: Struts Users Mailing List > Subject: RE: Please help clarify or confirm -- HttpSession > > > I haven't noticed anyone else pointing this out yet, so I guess maybe I > should... The approach described below (as far as I can see) > will only work > if you assume your app will never be deployed on more than a > single server - > or if you are fine with the fact that this 'shared' object will > not actually > be shared across multiple server instances in the cluster. > > If you can be certain you will never need to scale your apps to more than > one server this may be appropriate, but personally I would be very leary > about relying on this for any real project... YMMV > > Ralph Roland > Strata-J > [EMAIL PROTECTED] > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > > Sent: Thursday, June 13, 2002 4:04 PM > > To: Struts Users Mailing List > > Subject: RE: Please help clarify or confirm -- HttpSession > > > > > > > > > > OK. I checked this out. > > > > I'm running Tomcat 4.03 on NT with JDK 1.3.1. > > > > I created a simple static class: > > ------------------------- > > public class ClassLoaderTest { > > > > public static int counter; > > > > public static void addCounter() { > > counter++; > > } > > > > public static String getCounter () { > > return Integer.toString(counter); > > } > > } > > > > > > I compiled it and put the .class file in %CATALINA_HOME%\classes > > > > ------------------------- > > > > I then created a simple jsp named "test.jsp" > > > > <%@ page import="ClassLoaderTest" %> > > <html> > > <head> > > <title>Testing Class Loaders</title> > > </head> > > <body> > > <% ClassLoaderTest.addCounter(); %> > > <% out.print("Counter = " + ClassLoaderTest.getCounter() ); %> > > </body> > > </html> > > > > ------------------------- > > > > I then created two webapps, "webapp1" and "webapp2". They are > > completely empty except for the test.jsp file and the following > > web.xml file: > > > > <?xml version="1.0" encoding="ISO-8859-1"?> > > > > <!DOCTYPE web-app > > PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN" > > "http://java.sun.com/j2ee/dtds/web-app_2_2.dtd";> > > > > <web-app> > > > > <!-- The Usual Welcome File List --> > > <welcome-file-list> > > <welcome-file>index.jsp</welcome-file> > > </welcome-file-list> > > > > </web-app> > > > > > > > > Now - I then restarted Tomcat and opened two browsers. I pointed one to: > > > > http://localhost:8080/webapp1/test.jsp > > > > and the other to: > > > > http://localhost:8080/webapp2/test.jsp > > > > > > Then when I hit refresh on them I can see THEY ARE HITTING THE > > SAME OBJECT. That is, this works. The counter increments each > > time I refresh either > > browser. > > > > Thanks for the thoughts on this Joe - > > > > Kevin > > > > > > > > > > > > -- > > To unsubscribe, e-mail: > > <mailto:[EMAIL PROTECTED]> > > For additional commands, e-mail: > > <mailto:[EMAIL PROTECTED]> > > > > > > > -- > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
