how can i incorporate my reader file to my program

[blknmld69]

My program works reading from values that I have stored in an array for valid account numbers. I also have a file that reads the valid account numbers from a text file. I need to read from the text file and not the array.

reads from array

import java.util.Scanner; 
 
   public class ChargeAccount 
   { 
      static int[] validChargeAccountNumbers = 
      { 
         5658845, 4520125, 7895122, 8777541, 8451277, 1302850, 8080152, 
         4562555, 5552012, 5050552, 7825877, 1250255, 1005231, 6545231, 
         3852085, 7576651, 7881200, 4581002 
         }; 
 
      public static void main(String[] args) 
      { 
         Scanner in = new Scanner(System.in); 
 
      // Ask the user for an account number 
         System.out.print("Please enter an account number: "); 
 
      // Get the number from the user 
         int number = in.nextInt(); 
 
      // Check to see if the number is valid 
         if (ChargeAccount.isValid(number) == true) 
         { 
            System.out.println("That account number is valid."); 
         } 
 
         else 
         { 
            System.out.println("You did not enter a valid account number."); 
         } 
      } 
 
       // Check to see if an account number is valid by comparing it to the entries in the array of valid numbers 
      public static boolean isValid(int number)       
      { 
 
      // Perform sequential search through list of valid account numbers 
         for (int i = 0; i < validChargeAccountNumbers.length; i++) 
         { 
 
      // Check to see if the number we were given is at the ith position in the list 
         if (validChargeAccountNumbers[i] == number) 
         { 
            return true; 
         } 
      } 
 
      // If we get down here, then we never found it in the list 
             return false; 
      } 
   }
 

file reader

mport java.io.*;
 
 
   class FileReadTest 
   {
      public static void main (String[] args) 
      {
         FileReadTest f = new FileReadTest();
         f.readMyFile();
      }
 
      void readMyFile() 
      {
         DataInputStream dis = null;
         String record = null;
         int recCount = 0;
 
         try 
         {
            File f = new File("valid_accounts.txt");
            FileInputStream fis = new FileInputStream(f);
            BufferedInputStream bis = new BufferedInputStream(fis);
            dis = new DataInputStream(bis);
 
            while ( (record=dis.readLine()) != null ) 
            {
               recCount++;
               System.out.println(recCount + ": " + record);
            }
         } 
 
            // catch io errors from FileInputStream or readLine()
            catch (IOException e) 
            {
               System.out.println("Uh oh, got an IOException error!" + e.getMessage());
            } 
 
         finally 
         {
 
          // if the file opened okay, make sure we close it
            if (dis != null) 
            {
               try 
               {
                  dis.close();
               } 
                  catch (IOException ioe) 
                  {
                  }
            }
         }
      }
   }
 

[Oralloy]

Ouch. Then you are one frustrated kid.

Still, your code looks good. All you need is the read-file bit and you're done.

Did you ever bother to read that link I sent?

This is a simplified bit of code that might work for you, but it'll never fly in a production environment where people seem to put all kinds of junk in files. The problem is, of course, in error detection and reporting:

try {
  Scanner s = new Scanner(new File(fileName));
 
  while(s.hasNextInt())
    validChargeAccountNumbers.add(s.nextInt());
} catch (FileNotFoundException e) {
  e.printStackTrace();
}

[blknmld69]

lol very confused old man (44). I will try that.

[Oralloy]

Eeeep, that makes me ancient (48).

[blknmld69]

where would that go?

[Oralloy]

Do you understand what the code example does?

[blknmld69]

it looks like it reading from the file validChargeAcco untNumber

[blknmld69]

ok so it should be in the readMyFile method?

[Oralloy]

Yep.

So that's probably the core of your method "ReadMyFile ()".

What is important is how you incorporate it.

Since you're a student, I assume that you don't have any strong idea of exception handling, and how to use it. That's why the example (chicken-sh*t) exception handler.

At some level you'll have to deal with I/O errors in your program. You might just be able to declare all your methods as "throws Exception", and that's it. I really don't know what your instructor's exception handling requirements are.

Hopefully you can test and you'll be done in a couple minutes. Your post #7 looks pretty good, otherwise.

[blknmld69]

i get the error when i do it like that:
ChargeAccount.j ava:54: cannot find symbol
symbol : class File
location: class ChargeAccount
Scanner s = new Scanner(new File());
^
ChargeAccount.j ava:58: cannot find symbol
symbol : class FileNotFoundExc eption
location: class ChargeAccount
catch (FileNotFoundEx ception e)
^
2 errors

[Oralloy]

Ok, good start.

Did you remember to import the requisite classes. Either with the blanket imports:

import java.io.*;
import java.util.*;

or explicitly:

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

BTW, is this your first or second Java program? *friendly-laugh*