change password of user account in java using text files?

Question

I have a problem and hope to find a solution.

now i have created a simple program to change password of user account using text files in java.

now i should enter username of the account then change password of that account but there it shows me an error.

here is my code:

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Objects;
import java.util.Scanner;

public class Test6 {
public static void main(String[] args)throws IOException {

    String newPassword=null;
    boolean checked = true;

 File f= new File("C:\\Users\\فاطمة\\Downloads\\accounts.txt");// path to your file
 File tempFile = new File("C:\\Users\\فاطمة\\Downloads\\accounts2.txt"); // create a temp file in same path
 BufferedWriter writer = new BufferedWriter(new FileWriter(tempFile));
 Scanner sc = new Scanner(f);
 System.out.println("Enter account username you want to edit password?");
 Scanner sc2 = new Scanner(System.in);
 String username = sc2.next();
 while(sc.hasNextLine())
 {
     String currentLine= sc.nextLine();
     String[] tokens = currentLine.split(" ");
     if(Objects.equals(Integer.valueOf(tokens[0]), username) && checked)
     {
         sc2.nextLine();                          
         System.out.println("New Password:");
         newPassword= sc2.nextLine();
         currentLine = tokens[0]+" "+newPassword;
         checked = false;
     }
     writer.write(currentLine + System.getProperty("line.separator"));

 }
 writer.close(); 
 sc.close();
 f.delete();
 boolean successful = tempFile.renameTo(f);

}
}

the error shows to me:

Exception in thread "main" java.lang.NumberFormatException: For input string: "HAMADA"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at java.lang.Integer.valueOf(Integer.java:766)
at Test6.main(Test6.java:25)

the format of my text file is like that:

HAMADA 115599
JOHNY 4477100

Jonathan Lam · Accepted Answer · 2015-11-01 19:34:50Z

2

Change Integer.valueOf(tokens[0]) on line 25 to just tokens[0].

In your code, you try to get the integer value of the username, when you should be getting its String representation. You do not need the Integer.valueOf(). (The error is thrown because you are trying to get the Integer representation of a non-integer type.)

On a side note, you should never have password-storing text files, especially when the passwords and the files are both unencrypted. Use a database instead.

answered Nov 1, 2015 at 19:34

Jonathan Lam

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1 Comment

Jonathan Lam Over a year ago

@BeginnerProgrammer No problem. I'm glad it helped!

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