Call a number of servlets with the same session

Question

Hi,
for a purpose of performance testing I need to write a servlet that will call a number of servlets in a existing web application.
It will measure a average execution time of each servlet. The sequence of servlet names and arguments is stored in a xml file, which is accessed by the testing servlet.
For example:
<servlet>
        <name>ListExtras</name>
        <params>?dateLocale=en&dateFormat=dd/MM/yyyy&contentId=&staticDateFormat=dd MMMM yyyy&interfaceid=1243941814581</params>
</servlet>
<servlet>
        <name>ListFilters</name>
        <params>?dateLocale=en&dateFormat=dd/MM/yyyy&contentId=&staticDateFormat=dd MMMM yyyy&interfaceid=1243941814581</params>
</servlet>Moreover such testing scenario will be executed simultaneously for several user - I will create a thread for each user and call the sequence of servlets from the xml file. Results of measurements will be stored in a file.
In our web application a gatway between client and server in a Dispatcher class which forwards client requests to a specific servlet according to provided command parameter.
So having a servlet name and parameter I do as follows:
stopWatch.start();
URL servlerURL= new URL(dispatcherURL  +servletParams+  "&command="  +servletName);+
+BufferedReader in = new BufferedReader(new InputStreamReader(servlerURL.openStream()));+
+stopWatch.stop();+
+String inputLine;+
+while ((inputLine = in.readLine()) != null) {+
+     result.append(inputLine);+
+}+
+in.close();+
++
This way I can measure time of servlet execution and moreover I can store the result of execution in StringBuffer.
The problem is that each time I call the Dispatcher this way I get a different sessionId - so that objects stored in the session object by previous servlet cannot be accessed by the following one.
I tried calling the Dispatcher using an other RequestDispatcher, like this:
+RequestDispatcher rd = getServletContext().getRequestDispatcher("/xml/Dispatcher"+  servletParams  +"&command="+  servletName);But this throws java.lang.IllegalStateException: Cannot forward after response has been committed.
So the question is: How can I call various servlets, provide request parameters and keep the same sessionId for each call? And BTW sorry for such a long post, but I wanted to explain the problem is details, because it might be that you will provide a completely different solution.
Thank you in advance for answering!

Answer 1

Or investigate the [catus framework|http://jakarta.apache.org/cactus/].
If you understand very well how j2ee web applications work and then understand the cactus f/w, you can easily tweak it to meet your requirements.
ram.