BankingSystem.java

gistfile1.txt

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
import java.util.InputMismatchException;

// Account class representing a bank account
class Account {
    private int accountNumber;
    private String accountHolder;
    private double balance;

    public Account(int accountNumber, String accountHolder, double initialBalance) {
        this.accountNumber = accountNumber;
        this.accountHolder = accountHolder;
        this.balance = initialBalance;
    }

    public int getAccountNumber() {
        return accountNumber;
    }

    public String getAccountHolder() {
        return accountHolder;
    }

    public double getBalance() {
        return balance;
    }

    // Deposit funds into the account
    public void deposit(double amount) {
        if (amount > 0) {
            balance += amount;
            System.out.println("Deposit successful. New balance: $" + balance);
        } else {
            System.out.println("Invalid deposit amount.");
        }
    }

    // Withdraw funds from the account
    public boolean withdraw(double amount) {
        if (amount > 0 && amount <= balance) {
            balance -= amount;
            System.out.println("Withdrawal successful. New balance: $" + balance);
            return true;
        } else {
            System.out.println("Invalid withdrawal amount or insufficient funds.");
            return false;
        }
    }
}

// Bank class representing the bank's core functionality
class Bank {
    private String bankName;
    private Map<Integer, Account> accounts;

    public Bank(String bankName) {
        this.bankName = bankName;
        accounts = new HashMap<>();
    }

    // Create a new account
    public void createAccount(int accountNumber, String accountHolder, double initialBalance) {
        if (accounts.containsKey(accountNumber)) {
            System.out.println("Account already exists with this number.");
        } else {
            Account newAccount = new Account(accountNumber, accountHolder, initialBalance);
            accounts.put(accountNumber, newAccount);
            System.out.println("Account created successfully for " + accountHolder);
        }
    }

    // Get an account by account number
    public Account getAccount(int accountNumber) {
        return accounts.get(accountNumber);
    }

    // Transfer funds between two accounts with added validation
    public void transferFunds(int fromAccountNumber, int toAccountNumber, double amount) {
        if (fromAccountNumber == toAccountNumber) {
            System.out.println("Transfer failed: Cannot transfer funds to the same account.");
            return;
        }
        Account fromAccount = accounts.get(fromAccountNumber);
        Account toAccount = accounts.get(toAccountNumber);

        if (fromAccount == null || toAccount == null) {
            System.out.println("Invalid account number(s) provided for transfer.");
            return;
        }
        if (fromAccount.withdraw(amount)) {
            toAccount.deposit(amount);
            System.out.println("Transfer of $" + amount + " from account " 
                + fromAccountNumber + " to account " + toAccountNumber + " successful.");
        } else {
            System.out.println("Transfer failed due to insufficient funds.");
        }
    }
}

// Main class to run the banking system application
public class BankingSystem {
    public static void main(String[] args) {
        Bank pgb = new Bank("Prudent Global Bank");
        Scanner scanner = new Scanner(System.in);
        boolean running = true;

        // Sample accounts for demonstration
        pgb.createAccount(1001, "Alice Johnson", 5000);
        pgb.createAccount(1002, "Bob Smith", 3000);

        while (running) {
            System.out.println("\n--- Prudent Global Bank Menu ---");
            System.out.println("1. Create Account");
            System.out.println("2. Deposit");
            System.out.println("3. Withdraw");
            System.out.println("4. Transfer Funds");
            System.out.println("5. Check Balance");
            System.out.println("6. Exit");
            System.out.print("Enter your choice: ");
            int choice = 0;
            try {
                choice = scanner.nextInt();
            } catch (InputMismatchException e) {
                System.out.println("Invalid input. Please enter a number for the choice.");
                scanner.next(); // clear invalid input
                continue;
            }

            switch (choice) {
                case 1:
                    try {
                        System.out.print("Enter account number: ");
                        int newAccNum = scanner.nextInt();
                        scanner.nextLine(); // consume newline
                        System.out.print("Enter account holder name: ");
                        String name = scanner.nextLine();
                        System.out.print("Enter initial deposit: ");
                        double initialDeposit = scanner.nextDouble();
                        pgb.createAccount(newAccNum, name, initialDeposit);
                    } catch (InputMismatchException e) {
                        System.out.println("Invalid input. Please enter valid numeric values for account number and initial deposit.");
                        scanner.nextLine(); // clear invalid input
                    }
                    break;
                case 2:
                    try {
                        System.out.print("Enter account number for deposit: ");
                        int depAccNum = scanner.nextInt();
                        System.out.print("Enter deposit amount: ");
                        double depositAmount = scanner.nextDouble();
                        Account depAccount = pgb.getAccount(depAccNum);
                        if (depAccount != null) {
                            depAccount.deposit(depositAmount);
                        } else {
                            System.out.println("Account not found.");
                        }
                    } catch (InputMismatchException e) {
                        System.out.println("Invalid input. Please enter valid numeric values.");
                        scanner.nextLine(); // clear invalid input
                    }
                    break;
                case 3:
                    try {
                        System.out.print("Enter account number for withdrawal: ");
                        int witAccNum = scanner.nextInt();
                        System.out.print("Enter withdrawal amount: ");
                        double withdrawalAmount = scanner.nextDouble();
                        Account witAccount = pgb.getAccount(witAccNum);
                        if (witAccount != null) {
                            witAccount.withdraw(withdrawalAmount);
                        } else {
                            System.out.println("Account not found.");
                        }
                    } catch (InputMismatchException e) {
                        System.out.println("Invalid input. Please enter valid numeric values.");
                        scanner.nextLine(); // clear invalid input
                    }
                    break;
                case 4:
                    try {
                        System.out.print("Enter source account number: ");
                        int srcAcc = scanner.nextInt();
                        System.out.print("Enter destination account number: ");
                        int destAcc = scanner.nextInt();
                        System.out.print("Enter transfer amount: ");
                        double transferAmount = scanner.nextDouble();
                        pgb.transferFunds(srcAcc, destAcc, transferAmount);
                    } catch (InputMismatchException e) {
                        System.out.println("Invalid input. Please enter valid numeric values.");
                        scanner.nextLine(); // clear invalid input
                    }
                    break;
                case 5:
                    try {
                        System.out.print("Enter account number to check balance: ");
                        int balAcc = scanner.nextInt();
                        Account balAccount = pgb.getAccount(balAcc);
                        if (balAccount != null) {
                            System.out.println("Account " + balAcc + " balance: $" + balAccount.getBalance());
                        } else {
                            System.out.println("Account not found.");
                        }
                    } catch (InputMismatchException e) {
                        System.out.println("Invalid input. Please enter a valid account number.");
                        scanner.nextLine(); // clear invalid input
                    }
                    break;
                case 6:
                    running = false;
                    System.out.println("Exiting the system. Thank you.");
                    break;
                default:
                    System.out.println("Invalid choice. Please select again.");
            }
        }

        scanner.close();
    }
}