ATM.java

import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;
import java.util.logging.*;

public class ATM {

    private static final Logger logger = Logger.getLogger(ATM.class.getName());
    private static final String LOG_FILE = "atm.log";

    public static void main(String[] args) {

        setupLogger();

        logger.info("ATM Application Started");

        Scanner scanner = new Scanner(System.in);
        double balance = 1000.0;

        while (true) {

            System.out.println("1. Check Balance");
            System.out.println("2. Deposit");
            System.out.println("3. Withdraw");
            System.out.println("4. Print Statement");
            System.out.println("5. Exit");
            System.out.print("Choose an option: ");

            int choice = scanner.nextInt();

            switch (choice) {

                case 1:
                    checkBalance(balance);
                    break;

                case 2:
                    balance = deposit(balance, scanner);
                    break;

                case 3:
                    balance = withdraw(balance, scanner);
                    break;

                case 4:
                    printStatement(balance);
                    break;

                case 5:
                    logger.info("ATM Application Closed");
                    scanner.close();
                    return;

                default:
                    System.out.println("Invalid option.");
                    logger.warning("Invalid menu choice: " + choice);
            }
        }
    }

    private static void setupLogger() {

        try {

            logger.setUseParentHandlers(false);
            logger.setLevel(Level.ALL);

            ConsoleHandler consoleHandler = new ConsoleHandler();
            consoleHandler.setLevel(Level.ALL);

            FileHandler fileHandler = new FileHandler(LOG_FILE, true);
            fileHandler.setLevel(Level.ALL);

            Formatter formatter = new SimpleFormatter() {
                @Override
                public synchronized String format(LogRecord record) {

                    return String.format(
                            "%1$tF %1$tT | %-7s | %-20s | %s%n",
                            record.getMillis(),
                            record.getLevel(),
                            record.getSourceMethodName(),
                            record.getMessage()
                    );
                }
            };

            consoleHandler.setFormatter(formatter);
            fileHandler.setFormatter(formatter);

            logger.addHandler(consoleHandler);
            logger.addHandler(fileHandler);

        } catch (IOException e) {

            System.err.println("Failed to configure logger.");
            e.printStackTrace();
        }
    }

    private static void checkBalance(double balance) {

        logger.fine("Entered checkBalance()");

        System.out.printf("Current Balance: $%.2f%n", balance);

        logger.info("Balance checked: $" + balance);
    }

    private static double deposit(double balance, Scanner scanner) {

        logger.fine("Entered deposit()");

        System.out.print("Enter amount to deposit: ");

        double amount = scanner.nextDouble();

        if (amount <= 0) {

            System.out.println("Invalid deposit amount.");

            logger.severe("Invalid deposit amount: $" + amount);

            return balance;
        }

        balance += amount;

        System.out.printf("$%.2f deposited successfully.%n", amount);

        logger.info("Deposited $" + amount + ". Current balance: $" + balance);

        return balance;
    }

    private static double withdraw(double balance, Scanner scanner) {

        logger.fine("Entered withdraw()");

        System.out.print("Enter amount to withdraw: ");

        double amount = scanner.nextDouble();

        if (amount <= 0) {

            System.out.println("Invalid withdrawal amount.");

            logger.severe("Invalid withdrawal amount: $" + amount);

            return balance;
        }

        if (amount > balance) {

            System.out.println("Insufficient balance.");

            logger.warning("Withdrawal failed. Requested: $" + amount +
                    ", Available: $" + balance);

            return balance;
        }

        balance -= amount;

        System.out.printf("$%.2f withdrawn successfully.%n", amount);

        logger.info("Withdrawn $" + amount + ". Remaining balance: $" + balance);

        return balance;
    }

    private static void printStatement(double balance) {

        logger.fine("Entered printStatement()");

        try {

            FileWriter writer = new FileWriter("statement.txt");

            writer.write("===== ATM Statement =====\n");
            writer.write("Current Balance: $" + balance + "\n");

            writer.close();

            System.out.println("Statement saved successfully.");

            logger.info("Statement written to statement.txt");

        } catch (IOException e) {

            logger.log(Level.SEVERE,
                    "Failed to write statement file.",
                    e);
        }
    }
}