page forwarding from servlets error

[port1536]

Hi

I have had a null pointer exception with this method in a servlet


private void gotoPage( String Address,
HttpServletRequest request,
HttpServletResponse response)

throws ServletException , IOException {
RequestDispatcher dispatcher =
getServletContext().getRequestDispatcher(Address);
dispatcher.forward(request, response);
}



when used in the following scenario

page1 -> servlet1 -> page2 -> servlet2 ->{fails} back to page 2

I can forward ok from servlet1 to page2

servlet2 "hangs" in the browser and there is a null pointer exception
in the gotoPage method -.

are there any particular things which i need to set up to forward to any page for the second time?


java.lang.NullPointerException
at javax.servlet.GenericServlet.getServletContext(GenericServlet.java:205)
at orders.submitData.gotoPage(submitData.java:31)
at orders.submitData.performTask(submitData.java:321)
at orders.submitData.doGet(submitData.java:53)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:721)
at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:306)
at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:767)
at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:259)
at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:106)
at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run(PooledExecutor.java:797)
at java.lang.Thread.run(Thread.java:484)
Process exited.


Any ideas on how I can find out what is causing the problem or fix it?

Second question : Is it better to have one servlet which controls all logic rather than two or more servlets - any comments gratefully appreciated

Many thanks

 

[sedj]

Are you sure that "Address" is not null ...

>>>> Second question : Is it better to have one servlet which controls all logic rather than two or more servlets - any comments gratefully appreciated
In my opinion, if you use multiple servlets and multiple JSP, you may as well just bin the servlets, and do everything in JSP - I mean, they get compiled to servlets anyway !
There is a big debate about this number of servlets/design model, JSP scriplets vs JSP tags etc.... in theory the MVC 2 pattern is really nice, but taken to extremes with frameworks like Struts can sometimes be massive overkill, if the application is not huge.

Take a look at :

http://java.sun.com/blueprints/patterns/MVC-detailed.html

for a "thumbs up MVC" take on things.

 

[port1536]

config was null - unsure if this was the problem and no time to investigate - any ideas anyone?



but used the following as a work around

response.sendRedirect("../page.jsp"