Unknown exception in netbeans java while connecting oracle database

Question

I am following MVC pattern in java netbeans for some project. I am trying to connect database with my application and run a simple query of show all data in a JTable. I coded perfectly but when I run my project it throws an error:

package com.innovatraasolutions.eev.dal;

import com.innovatraasolutions.eev.bo.Voters;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.sql.*;
/**
 *
 * @author SuperMan
 */
public class VoterDAO {

    /**
     *
     * @param voter
     * @return
     */
    public List<Voters> verifyVoter(Voters voter){
       String filename = null;
       FileReader userFileReader = null;
       FileReader userFileReader2 = null;
       Connection connection = null;

       List<Voters> list = new ArrayList<Voters>();

       try{
           String driverName = "oracle.jdbc.driver.OracleDriver";
           Class.forName(driverName);
           String serverName = "SpiderMan";
           String serverPort = "1521";
           String sid = "XE";
           String url = "jdbc|oracle|thin|@" + serverName + "|" + serverPort + "|";
           String userName = "eev";
           String password = "123";

           connection = DriverManager.getConnection(url, userName, password);

           System.out.println("Sucessfully connected to the DataBase");  
       } catch(ClassNotFoundException e){
           System.out.println("Class Not Found Exeption::Couldn't find the database driver" + e.getMessage());
       } catch(SQLException e) {
           System.out.println("Couldn't connect to the database" + e.getMessage());
       }

       /*---------------------------------------------------*/
        //for retrieving data from database
       try{
           Statement statement = connection.createStatement();
           ResultSet resultSet  = statement.executeQuery("select *from Voter");

           while(resultSet.next()){
               String vcnic = resultSet.getString(1);
               voter.setCnic(vcnic);

               String Fname = resultSet.getString(2).toString();
               voter.setFname(Fname);

               String Lname = resultSet.getString(3).toString();
               voter.setLname(Lname);

               String VoteRegisteredIn = resultSet.getString(4).toString();
               voter.setVoteRegistered(VoteRegisteredIn);

               String Address = resultSet.getString(5).toString();
               voter.setAddress(Address);

               list.add(voter);
           }
           resultSet.close();

       }catch(Exception e){
           e.printStackTrace();
       }
       return list; 

   /*   try{
           userFileReader = new FileReader("voters.txt");
           String line = "a";
           BufferedReader voterFileBuffReader = new BufferedReader(userFileReader);

            while((line = voterFileBuffReader.readLine()) != null){
               // System.out.println("Yesss");
                //filename = line + ".txt";
                //System.out.println(filename);
                //System.out.println("first While");

                userFileReader2 = new FileReader("voters.txt");
                BufferedReader studFileBuffReader = new BufferedReader(userFileReader2);

                while((line = studFileBuffReader.readLine()) != null){
                    //System.out.println("Second While");
                    String Cnic = line;
                    voter.setCnic(Cnic);

                    String Fname = studFileBuffReader.readLine();
                    voter.setFname(Fname);

                    String Lname = studFileBuffReader.readLine();
                    voter.setLname(Lname);

                    String VoteRegistered = studFileBuffReader.readLine();
                    voter.setVoteRegistered(VoteRegistered);

                    String Address = studFileBuffReader.readLine();
                    voter.setAddress(Address);

                    list.add(voter);


        }

     }

  }*/
      /* catch(Exception e){
           System.err.println("Exception::");
       } */ 

 }

}

And it is giving the following error:

run:
File not found!
Couldn't connect to the databaseNo suitable driver found for jdbc|oracle|thin|@SpiderMan|1521|
java.lang.NullPointerException
    at com.innovatraasolutions.eev.dal.VoterDAO.verifyVoter(VoterDAO.java:58)
    at com.innovatraasolutions.eev.bl.VoterHandler.verifyVoter(VoterHandler.java:27)
    at com.innovatraasolutions.eev.controller.Controller.verifyVoter(Controller.java:83)
    at com.innovatraasolutions.eev.controller.Controller.processRequest(Controller.java:43)
    at com.innovatraasolutions.eev.ui.Voter.viewVoterActionPerformed(Voter.java:125)
    at com.innovatraasolutions.eev.ui.Voter.access$000(Voter.java:21)
    at com.innovatraasolutions.eev.ui.Voter$2.actionPerformed(Voter.java:75)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2346)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6525)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at java.awt.Component.processEvent(Component.java:6290)
    at java.awt.Container.processEvent(Container.java:2234)
    at java.awt.Component.dispatchEventImpl(Component.java:4881)
    at java.awt.Container.dispatchEventImpl(Container.java:2292)
    at java.awt.Component.dispatchEvent(Component.java:4703)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4898)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4533)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4462)
    at java.awt.Container.dispatchEventImpl(Container.java:2278)
    at java.awt.Window.dispatchEventImpl(Window.java:2739)
    at java.awt.Component.dispatchEvent(Component.java:4703)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:746)
    at java.awt.EventQueue.access$400(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:697)
    at java.awt.EventQueue$3.run(EventQueue.java:691)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
    at java.awt.EventQueue$4.run(EventQueue.java:719)
    at java.awt.EventQueue$4.run(EventQueue.java:717)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:716)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
BUILD SUCCESSFUL (total time: 31 seconds)

Possible duplicate of What is a NullPointerException, and how do I fix it? — Tom
– Tom, Commented Mar 12, 2017 at 12:00

SMA · Accepted Answer · 2015-01-11 18:02:52Z

2

You should change the following line from:

String url = "jdbc|oracle|thin|@" + serverName + "|" + serverPort + "|";

To

String url = "jdbc:oracle:thin:@" + serverName + ":" + serverPort + "/" + sid;

if you know the database name you can append it to be like:

String url = "jdbc:oracle:thin:@" + serverName + ":" + serverPort + ":" + dbname;

edited Jan 11, 2015 at 18:02

answered Jan 11, 2015 at 17:37

SMA

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3 Comments

Junaid Iqbal Over a year ago

sir now when i correct what you correct it, it's shows error:

Junaid Iqbal Over a year ago

File not found! java.lang.NullPointerException at com.innovatraasolutions.eev.dal.VoterDAO.verifyVoter(VoterDAO.java:59) Couldn't connect to the databaseListener refused the connection with the following error: ORA-12505, TNS:listener does not currently know of SID given in connect descriptor

SMA Over a year ago

See i updated answer. You might need to append "/" + sid to url

Manoj Kumar · Accepted Answer · 2015-01-11 17:36:56Z

0

Check whether your oracle driver .jar file is attached to your project. check this link [https://www.youtube.com/watch?v=jsS_cRbNv3o]

answered Jan 11, 2015 at 17:36

Manoj Kumar

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