New Problem

Hi again.
I've updated my prog and now ive got an entirely new error.
Im having a problem reading from a file.
Any help is appreciated.
I know i must have gone very wrong somewhere.
Cheers.

/**Logon Screens
 *@author Nathan Lasseter
 *@version 1.2.1
 *
 *Must be same number of users as passwords
 *but can have different number of domains
 *
 *Any user can access any domain
 */
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.EOFException;
import javax.swing.JOptionPane; //Import the JOptionPane package

public class hackingfile{ //begin main class
    public static void main(String args[]){ //begin executing from here
        String username,coreusers[][]; //input user and users
        String passcode; //input password
        String domain, coredoms[]; //input domain and domains
        int passcodeint; //integer passcode and passcodes
        int i=0,usernumber=0; //i for loops and usernumber for relating
user to pass
        Boolean user=false,pass=false,dom=false; //checks for
authentication

        DataInputStream in = new DataInputStream(new
BufferedInputStream(new FileInputStream(users.txt)));
        try{
            while(true){
                coreusers[i][0] = in.readUTF;
                coreusers[i][1] = in.readInt;
                i++;
            }
        }catch(EOFException e){}
        i=0;
        DataInputStream in = new DataInputStream(new BufferedInputStream(new
FileInputStream(domains.txt)));
        try{
            while(true){
                coredoms[i] = in.readUTF;
                i++;
            }
        }catch(EOFException e){}
        i=0;

        username = JOptionPane.showInputDialog("Enter UserName"); //get
username from user
        passcode = JOptionPane.showInputDialog("Enter PassCode"); //get
passcode from user
        domain = JOptionPane.showInputDialog("Enter Domain"); //get
domain from user
        passcodeint = Integer.parseInt(passcode); //parse string
passcode into integer

        for(i=0;i<coreuser.length;i++){ //check username
         if(username.equalsIgnoreCase(coreuser[i][0])){ //against list
         user = true; //if correct username is authentic
         usernumber=i; //get usernumber
         }
        }
        if(passcodeint == coreusers[usernumber][1]) pass = true; //if
correct then passcode is authentic
        for(i=0;i<coredoms.length;i++){ //check domain against list
         if(domain.equalsIgnoreCase(coredoms[i])) dom = true; //if
correct then domain is authentic
        }

        if(user & pass & dom){ //if username, passcode and domain are
authentic grant access
            JOptionPane.showMessageDialog(null,"Access Granted","Login
Successful",JOptionPane.PLAIN_MESSAGE); //show access is granted
        }else{ //else deny access
            JOptionPane.showMessageDialog(null,"Access Denied","Login
Unsuccessful",JOptionPane.PLAIN_MESSAGE); //show access is denied
        }
    } //end execution here
} //end main class

users.txt:
"admin" 101
"root" 798
"user1" 236
"nathan" 457

domains.txt:
"Google"
"LRGS"
"MyNet"