Servlet Chaining

[Satyen Singh]

Following is my code which throws "Null Pointer Exception" can anyone please tell me where exactly I am wrong

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;

public class ServletChain extends HttpServlet
{
	public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException
	{
		int number=0;
		try
		{
			number=Integer.parseInt(request.getParameter("txtNumber"));
			System.out.println("Servlet 1 :- You have Entered a Valid Number. Good!!!");
			request.setAttribute("number",""+number);
			RequestDispatcher requestDispatcher=getServletContext().getRequestDispatcher("/chain2");
			requestDispatcher.forward(request,response);
		}
		catch(NumberFormatException numberException)
		{
			System.out.println("Servlet 1 :- Sorry! You have Entered an Invalid Number");
		}
		catch(Exception exception)
		{
			exception.printStackTrace();
		}
	}
}

And Following is the Error

java.lang.NullPointerException
        at ServletChain.doGet(ServletChain.java:16)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:627)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:269)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:188)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperV
alve.java:213)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextV
alve.java:172)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.j
ava:127)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.j
ava:117)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineVal
ve.java:108)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.jav
a:174)
        at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcesso
r.java:843)
        at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.pr
ocess(Http11AprProtocol.java:679)
        at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:13
03)
        at java.lang.Thread.run(Thread.java:595)

Thanks in Advance.........

[Rob Spoor]

Your RequestDispatcher is null, as is allowed to be returned:

Returns:
a RequestDispatcher object that acts as a wrapper for the resource at the specified path, or null if the ServletContext cannot return a RequestDispatcher

[Satyen Singh]

Thanks Rob,
It is working.......

[Rob Spoor]

You're welcome.