Database Connection Pooling java.lang.NullPointerException. Help please

[agustinus lumbantoruan]

Dear Pros and Noobs

I am stuck with the Database Connection Pooling problem.
I have created and tested a Database Pooling successfully.
But recently I have faced a problem saying

java.lang.NullPointerException
	malo.java.classes.CommentDB.getProfileComments(CommentDB.java:44)
	malo.controller.ProfileController.processRequest(ProfileController.java:91)
	malo.controller.ProfileController.doGet(ProfileController.java:168)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)

Could anyone help me to solve the problem please. Before I post this, I have tried to find the answer in the Internet and coderanch but the solution didn't work for mine.
www.coderanch.com/t/.../Connection-Pooling-null-pointer-exception
https://coderanch.com/t/474377/Tomcat/Tomcat-Connection-Pooling

Context.xml
I put the context.xml in the C:\Users\Bio\.netbeans\6.9\apache-tomcat-6.0.26_base\conf folder.

<?xml version='1.0' encoding='utf-8'?>
<!--
  Licensed to the Apache Software Foundation (ASF) under one or more
  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
  The ASF licenses this file to You under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
-->
<!-- The contents of this file will be loaded for each web application -->
<Context path="/TestingGround" docBase="dbcp" debug="5"
reloadable="true" crossContext="true">


    <!-- Default set of monitored resources -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>
<Resource
    name="jdbc/MaloDB"
    type="javax.sql.DataSource"
    removeAbandoned="true"
    removeAbandonedTimeout="30"
    maxActive="100"
    maxIdle="30"
    maxWait="1"
    driverClassName="com.mysql.jdbc.Driver"
    url="jdbc:mysql://localhost:3306/Malo"
    username="root"
    password="password"
/>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->
    <!--
    <Manager pathname="" />
    -->

    <!-- Uncomment this to enable Comet connection tacking (provides events
         on session expiration as well as webapp lifecycle) -->
    <!--
    <Valve className="org.apache.catalina.valves.CometConnectionManagerValve" />
    -->

</Context>

ProfileController.java
In ProfileController.java, I open and close the Database Connection once.
The first connection I use it to retrieve the profile information in line 83.
The second connection I use it to retrieve the user's profile comments in line 99

package malo.controller;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.sql.DataSource;
import malo.java.classes.Comment;
import  malo.java.classes.Profile;
import malo.java.classes.CommentDB;
import malo.java.classes.ProfileDB;
/**
 *
 * @author Bio
 */
public class ProfileController extends HttpServlet {
    private ServletContext forward;
    private DataSource dataSource;
   private Connection conn;
    private int pooledCount;
    private int nonPooledCount;

        /*
           Initialize the Database Connection from the pool
         * Get the Database Connection from getConnection().
getConnection is in line 140
         */
    @Override
   public void init()throws ServletException {
        try {
            conn = getConnection();
        } catch (SQLException ex) {
            Logger.getLogger(ProfileController.class.getName()).log(Level.SEVERE, null, ex);
        } catch (NamingException ex) {
            Logger.getLogger(ProfileController.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    @Override
    public void destroy() {
        try {
            conn.close();
        } catch (SQLException ex) {
            Logger.getLogger(ProfileController.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException, NamingException, SQLException, ClassNotFoundException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        /*Get an existing session.
         * If the session does not exist, create one. Later we will check the session attributes nullity
         */
        HttpSession session = request.getSession(true);
        //get Parameter
        String id=request.getParameter("userID");
        String index = request.getParameter("Index");
            if(index==null){
                index="1";
            }
       
        //Get the profile informations
        Profile profile = new Profile();
        ProfileDB profileDB=new ProfileDB(profile);
        profileDB.GetProfileInfo(conn, Integer.parseInt(id));
        profile=profileDB.getProfile();

        Comment comment = new Comment();
        CommentDB commentDB = new CommentDB();
        commentDB.getProfileComments(conn, Integer.parseInt(id), "commenttable", Integer.parseInt(index)*10-10,Integer.parseInt(index)*10);
        //Set the comment object to a comment type form commentDB.getComment()
        comment=commentDB.getComment();
        comment.setCommentIndex(Integer.parseInt(index));
        comment.setTotalComment(commentDB.getTotalRow());
    try{
        //Get the userAutentication session Attribute
        malo.java.classes.UserAuthentication userAuthentication=(malo.java.classes.UserAuthentication) session.getAttribute("usersAuthentication");
        if(userAuthentication==null){
            userAuthentication=new malo.java.classes.UserAuthentication();
            //Set the setIsMember()function to false, we will use this info to authenticate in the Profile. Such as display the login button etc
            userAuthentication.setIsMember(false);
            out.println("No Session Attribute");
            session.setAttribute("userAuthentication", userAuthentication);
            request.setAttribute("profile", profile);
            request.setAttribute("comment",comment);
            /*
            * Forward to the his/her profile page
            */
            RequestDispatcher rd;
            rd = request.getRequestDispatcher("ProfilePage?userID="+id);
            rd.forward(request,response);
       }
       else{
           //Get the existing session attribute and assign it to userAuthentication
            userAuthentication = (malo.java.classes.UserAuthentication) session.getAttribute("usersAuthentication");
            session.setAttribute("userAuthentication", userAuthentication);
            request.setAttribute("profile", profile);
            request.setAttribute("comment",comment);
                /*
                * Forward to the his/her profile page
                */
                RequestDispatcher rd;
                rd = request.getRequestDispatcher("ProfilePage?userID="+id);
                rd.forward(request,response);
            }
       }

       catch(IOException ioe){
           System.err.println("MurachPool IOException: " + ioe);
       }
        finally{
             try {if (conn != null) conn.close();} catch (SQLException e) {}
        }
    }

/*
Return the Connection from the pool
*/
     public Connection getConnection() throws SQLException, NamingException{
        // Obtain our environment naming context
        Context envCtx = (Context) new InitialContext();

        // Look up our data source
        DataSource  ds = (DataSource) envCtx.lookup("java:comp/env/jdbc/MaloDB");
        conn=ds.getConnection();
        return conn;
    }

     @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        try {
            processRequest(request, response);
        } catch (NamingException ex) {
            Logger.getLogger(ProfileController.class.getName()).log(Level.SEVERE, null, ex);
        } catch (SQLException ex) {
            Logger.getLogger(ProfileController.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(ProfileController.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        try {
            processRequest(request, response);
        } catch (NamingException ex) {
            Logger.getLogger(ProfileController.class.getName()).log(Level.SEVERE, null, ex);
        } catch (SQLException ex) {
            Logger.getLogger(ProfileController.class.getName()).log(Level.SEVERE, null, ex);
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(ProfileController.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}

Thank you guys.

God Bless