problem calling servlet to build a list of data from a database and display a jsp page

please need help solving the problem of calling a servlet to build list of data from a database and display it on a jsp page.anytime i run my jsp code it gives me a runtime error.

my servlet code

package com.web;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author Administrator
 */
public class DataServlet extends HttpServlet {
   
    private ServletConfig config;
	//Setting JSP page
	String page="DataPage.jsp";

public void init(ServletConfig config)
	  throws ServletException{
		 this.config=config;
	   }

@Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        PrintWriter out = response.getWriter();
		//Establish connection to MySQL database
		String connectionURL = "jdbc:mysql://localhost:3306/koenet";
		Connection connection=null;
		ResultSet rs;
		response.setContentType("text/html");
		List dataList=new ArrayList();
			try {
			 // Load the database driver
			Class.forName("com.mysql.jdbc.Driver");
			// Get a Connection to the database
			connection = DriverManager.getConnection(connectionURL, "root", "efekodo");
			//Select the data from the database
			String sql = "select * from personal_info";
			Statement s = connection.createStatement();
			s.executeQuery (sql);
			rs = s.getResultSet();
			while (rs.next ()){
				//Add records into data list
				dataList.add(rs.getInt("id"));
				dataList.add(rs.getString(2));
			}
			rs.close ();
			s.close ();
			}catch(Exception e){
			System.out.println("Exception is ;"+e);
			}
			request.setAttribute("data",dataList);
			//Disptching request
			RequestDispatcher dispatcher = request.getRequestDispatcher(page);
			if (dispatcher != null){
				dispatcher.forward(request, response);
			}
    }    
    
    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}

my jsp code

error message

org.apache.jasper.JasperException: An exception occurred processing JSP page /DataPage.jsp at line 23

20: 	  </tr>
21: 	<%Iterator itr;%>
22: 	<% List data= (List)request.getAttribute("data");
23: 		for (itr=data.iterator(); itr.hasNext(); )
24: 		{
25: 	%>
26: 	<tr>

Stacktrace:
	org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:505)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:416)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)

root cause

java.lang.NullPointerException
	org.apache.jsp.DataPage_jsp._jspService(DataPage_jsp.java:75)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)

thanks for usual understanding

List data= (List)request.getAttribute("data");

One thing to suspect is the request.getAttribute("data") returns null . Is the request originated from servlet ? or you directly hit the jsp.

And, how you map the servlet in web.xml & access the servlet from the URL?

yes,the request is originated from the servlet.am using netbean ide,i think the ide does the mapping for me.can some one help to find a solution. thanks

Efekodo Kingsley wrote:am using netbean ide,i think the ide does the mapping for me.can some one help to find a solution.

So, How do you deploy & invoke the servlet? Inside a web container? If so we need to see your web.xml mapping and URL used to invoke the servlet.

Is the servlet invoked at any way? Run a debugger or place sysouts at strategic locations printing the info or variables of interest.

Apart from the actual problem, you should not use scriptlets. Drop them all and use taglibs and EL. The JSTL's c:forEach tag is perfectly suitable for looping over a List.