The server encountered an internal error () that prevented it from fulfilling this re

[sid0404]

Hi

I am working with the Tomcat 5.5 on Eclipse, and is getting the error when my servlet calls the jsp using request dispatcher, the error is:

HTTP status 500

The server encountered an internal error () that prevented it from fulfilling this request.

and the log of the exception is:

Oct 27, 2008 9:41:15 AM org.apache.cata lina.core.Stand ardWrapperValve invoke
SEVERE: Servlet.service () for servlet Controller threw exception
java.lang.NullP ointerException
at Controller.doGe t(Controller.ja va:46)
at javax.servlet.h ttp.HttpServlet .service(HttpSe rvlet.java:627)
at javax.servlet.h ttp.HttpServlet .service(HttpSe rvlet.java:729)
at org.apache.cata lina.core.Appli cationFilterCha in.internalDoFi lter(Applicatio nFilterChain.ja va:269)
at org.apache.cata lina.core.Appli cationFilterCha in.doFilter(App licationFilterC hain.java:188)
at org.apache.cata lina.core.Stand ardWrapperValve .invoke(Standar dWrapperValve.j ava:213)
at org.apache.cata lina.core.Stand ardContextValve .invoke(Standar dContextValve.j ava:172)
at org.apache.cata lina.core.Stand ardHostValve.in voke(StandardHo stValve.java:12 7)
at org.apache.cata lina.valves.Err orReportValve.i nvoke(ErrorRepo rtValve.java:11 7)
at org.apache.cata lina.core.Stand ardEngineValve. invoke(Standard EngineValve.jav a:108)
at org.apache.cata lina.connector. CoyoteAdapter.s ervice(CoyoteAd apter.java:174)
at org.apache.coyo te.http11.Http1 1Processor.proc ess(Http11Proce ssor.java:875)
at org.apache.coyo te.http11.Http1 1BaseProtocol$H ttp11Connection Handler.process Connection(Http 11BaseProtocol. java:665)
at org.apache.tomc at.util.net.Poo lTcpEndpoint.pr ocessSocket(Poo lTcpEndpoint.ja va:528)
at org.apache.tomc at.util.net.Lea derFollowerWork erThread.runIt( LeaderFollowerW orkerThread.jav a:81)
at org.apache.tomc at.util.threads .ThreadPool$Con trolRunnable.ru n(ThreadPool.ja va:689)
at java.lang.Threa d.run(Unknown Source)

and when I go to the line in the controller.java which is giving me the exception, I do not find anything wrong with it, this is the line:

RequestDispatch er dispatcher = getServletConfi g().getServletC ontext().getReq uestDispatcher( "/view.jsp");
dispatcher.forw ard(request, response);

Any clarifications highly appreciated.

When I debug my code, I find that the config is null just before the RequestDispatch er line. What does that mean ?

thanks.

[JosAH]

You either didn't store your .jsp at the correct location or you have overridden the
init(ServletCon fig config) method without calling the super.init(conf ig) method.

kind regards,

Jos

[sid0404]

My code looks like this:

import java.io.IOException;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Servlet implementation class Controller
 */
public class Controller extends HttpServlet {
	
	private static ArrayList<String> list_operations = new ArrayList<String>();
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Controller() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see Servlet#init(ServletConfig)
	 */
	public void init(ServletConfig config) throws ServletException {
		// TODO Auto-generated method stub
	}

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		

		String val = request.getParameter("value1");
		System.out.println(val);
		
		HttpSession session = request.getSession(true);
		System.out.println(session.getId());
		RequestDispatcher dispatcher = getServletConfig().getServletContext().getRequestDispatcher("/view.jsp");
		dispatcher.forward(request, response);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub


		this.doGet(request, response);
		
	}

}

I dont think i did anything like that !! Any idea what is going wrong with the code !!

Reply awaited.

[JosAH]

I dont think i did anything like that !!

Yes you did; you committed sin #2 (see my previous reply).

kind regards,

Jos