Not able to dispatch to an URL from servlet

Question

Hi ,
I am trying to call a URL from a servlet, which is running in an oc4j instance of Oracle AS 10.1.2.0.2
My servlet (session_servlet) basically reads the session id, whenever it is accessed. It then inserts this session id into a table in an oracle database. Then, I want to access my Oracle Forms application from session_servlet, by dispatching to the URL, say
http://<my_host>/forms/frmservlet?config=test&session_id=<the_session_id_read_by_session_servlet>
session_servlet and frmservlet are running on the same Oracle AS, but on different http servers, session_servlet on port 7777 and frmservlet on the default 80.
<code snippet of my session_servlet, where I am dispatching to the URL>
getServletContext().getRequestDispatcher("http://<my_host>/forms/frmservlet?config=test&session_id="+session.getId()).forward(request,response);
But am getting the following error
500 Internal Server Error
java.lang.NullPointerException
at session_tracker.doGet(session_tracker.java:54)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.2)].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:826)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.2)].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:332)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.2)].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:830)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.2)].server.http.AJPRequestHandler.run(AJPRequestHandler.java:224)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.2)].server.http.AJPRequestHandler.run(AJPRequestHandler.java:133)
at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.2)].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)
at java.lang.Thread.run(Thread.java:534)
Can someone please help me on this.
Thanks,
Suresh

Answer 1

getServletContext().getRequestDispatcher("http://<my_host>/forms/frmservlet?config=test&session_id="+session.getId()).forward(request,response)
From the Javadocs for ServletContext.getRequestDispather():
http://java.sun.com/j2ee/1.4/docs/api/javax/servlet/ServletContext.html#getRequestDispatcher(java.lang.String)
The pathname must begin with a "/" and is interpreted as relative to the current context root. Use getContext to obtain a RequestDispatcher for resources in foreign contexts. This method returns null if the ServletContext cannot return a RequestDispatcher.
-steve-