How to well adjust a loop in Java?

Question

I am currently writing a little program to ask a PinCode to a user and return ":)" if the Pin is good or ":(" if the Pin is wrong. My code is made of one java file and one text file.

This is the code :

import java.io.*;
import java.util.*;

public class Main {

static public boolean readPinsData(File dataFile, ArrayList<Integer> data) {
   boolean err = false;
   try {
      Scanner scanner = new Scanner(dataFile);
      String line;
      while (scanner.hasNext()) {
         line = scanner.nextLine();
         try {
            data.add(Integer.parseInt(line));
         } catch (NumberFormatException e) {
            e.printStackTrace();
            err = true;
         }
      }
      scanner.close();
   } catch (FileNotFoundException e) {
      e.printStackTrace();
      err = true;
   }

   return err;
}


public static void main(String[] args) {

    System.out.println("-----------------------");
    System.out.println("MY APP");
    System.out.println("-----------------------");
    Console console = System.console();
    int pinSize = 0;
    int nbTry = 0;

    do{
      do{
    char passwordArray[] = console.readPassword("Enter pin: ");
    pinSize = passwordArray.length;

    if(pinSize != 4){
            System.out.println("Pin must be 4 digits");
        } else {
            System.out.println("Checking...");
        }


   ArrayList<Integer> pins = new ArrayList<Integer>();
   readPinsData(new File("bdd.txt"), pins);
   //System.out.println(pins);
   //System.out.println(passwordArray);


   String[] thePins = new String[pins.size()];
   for (int i = 0; i < thePins.length; i++) {
    thePins[i] = pins.get(i).toString();
}

   String passEntered = String.valueOf(passwordArray);





   for(int i = 0 ; i < thePins.length ; i++){
      if(passEntered.equals(thePins[i]) && pinSize == 4){
          System.out.println(":)");
        } else if(!passEntered.equals(thePins[i]) && pinSize == 4){
            nbTry++;
        }

    }   

  }while(nbTry < 3);
   }while(pinSize != 4);

}
}

This is bdd.txt where all the good Pins are stored :

1111
2222
3333
4444
5555
6666
7777
8888
9999

Actually my problem is to limit the number of try to 3 tries. I need to explain:

--> the user has to enter a pin

--> either he enters a good 4 digits pin and it prints ":)" (and the app is done)

--> either he enters a wrong 4 digits pin and it prints ":(" and the nbTry must be ++. In this case he has only 2 tries left

--> he also can enter a 1-digit pin or 2-digits pin or 3-digits pin ... and in this case nbTry is not affected, he just have to re-enter a 4 digits pin.

I can not find out how to do with the nbTry left part.. Any ideas ?

Answer 1

Do you want him to be able to enter a 4 digit pin only or do you want him to be able to enter any length of pin?

Edit:

Reading your main I saw that you have two 'do...while`. If you change the order of them it should work. I can't test it atm because I'm on mobile but try it like this:

do {
  do {
      ....
  } while (pinSize != 4);
} while (nbTry < 3);

Edit2:

boolean loginCorrect = false;
for (int i = 0; i < thePins.length; i++) {
   if (passEntered.equals(thePins[i]) && pinSize == 4) {
      System.out.println(":)");
      loginCorrect = true;
      break;
   } else if (!passEntered.equals(thePins[i]) && pinSize == 4) {
      System.out.println(":(");
   }

}
if(!loginCorrect && pinSize == 4){
   nbTry++;
}

Hope you got it as its hard to type on mobile.

The full main code: public static void main(String[] args) {

    System.out.println("-----------------------");
    System.out.println("MY APP");
    System.out.println("-----------------------");
    Console console = System.console();
    int pinSize = 0;
    int nbTry = 0;
    boolean authenticated = false;

    do {
        do {
            char passwordArray[] = console.readPassword("Enter pin: ");
            pinSize = passwordArray.length();

            if (pinSize != 4) {
                System.out.println("Pin must be 4 digits");
            } else {
                System.out.println("Checking...");
            }

            ArrayList<Integer> pins = new ArrayList<Integer>();
            readPinsData(new File("bdd.txt"), pins);
            // System.out.println(pins);
            // System.out.println(passwordArray);

            String[] thePins = new String[pins.size()];
            for (int i = 0; i < thePins.length; i++) {
                thePins[i] = pins.get(i).toString();
            }

            String passEntered = String.valueOf(passwordArray);

            for (int i = 0; i < thePins.length; i++) {
                if (passEntered.equals(thePins[i]) && pinSize == 4) {
                    System.out.println(":)");
                    authenticated = true;
                    break;
                }
            }

        } while (pinSize != 4);
        if (!authenticated && pinSize == 4) {
            System.out.println(":(");
            nbTry++;
        }
    } while (nbTry < 3 && !authenticated);
}