I have below run time error

java access_update
OK - Build connection
Setup con
Error: java.lang.NullPointerException null
java.lang.NullPointerException
       at
sun.jdbc.odbc.JdbcOdbcDriver.initialize(JdbcOdbcDriver.java:436)
       at
sun.jdbc.odbc.JdbcOdbcDriver.connect(JdbcOdbcDriver.java:153)
       at java.sql.DriverManager.getConnection(DriverManager.java:512)
       at java.sql.DriverManager.getConnection(DriverManager.java:171)
       at access_update.main(access_update.java:36)

Source code
/*  access_update.java

2006/08/14 eric.leung

*
* Source : HOME
*
*/

import java.sql.*;
import java.lang.*;

public class access_update {
    public static void main(String args[]) {
        // eric_jsp is ODBC User DNS
        // String url = "jdbc:odbc:eric_jsp";

        // Using DSNless connection
        String url = "";
        String machine = "xx.xx.26.45";
        url = "jdbc:odbc:DRIVER={Microsoft Access Driver (*.mdb)}" +
        ";SERVER= machine ;DBQ=c:\\example\\ERIC_JSP.mdb";

        Connection con;
        System.out.println("OK - Build connection");

    try {
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
    } catch (ClassNotFoundException e) {
        System.err.print("ClassNotFoundException " );
        System.err.println(e.getMessage());
    }

    try {
        System.out.println("Setup con");
        con = DriverManager.getConnection (url,"","");
        System.out.println("OK - Setup con");

        PreparedStatement p2 = con.prepareStatement("select count(*) from
pt_mstr where pt_part = ?");

       System.out.println("OK - Build PreparedStatement");
        p2.setString(1, "123");
        ResultSet r = p2.executeQuery();
        while (r.next()) System.out.println("How many rows have that value? "
+
        r.getInt(1) );
        r.close();
        p2.close();

        String sql = "Update pt_mstr set cnt = ? where pt_part = ?";
        PreparedStatement pstmt = con.prepareStatement(sql);

             // con.setAutoCommit(true);
         con.commit();
        pstmt.setInt(1,3000);
        pstmt.setString(2,"123");
           System.out.println(sql);

        pstmt.executeUpdate();

        // Close the connection
        con.close();

    } catch (SQLException ex) {
        // System.err.println("SQLException: " + ex.getMessage());
        ex.printStackTrace();
        }
     catch (Exception e) {
         System.err.println("Error: " + e.toString() + " " +
e.getMessage());
        e.printStackTrace();
         }   
    }
   
}