BankAccount.java

/**
 * A class to represent a single bank account.
 */
public class BankAccount {

    private double balance;
    private int accountNumber;
    
    /*
     * Constructor
     * @param initialBalance the initial balance of the BankAccount
     * @param accountNumber The account number to associate with this 
     *                      BankAccount.  Must be a 5 digit integer.
     */
    public BankAccount(double initialBalance, int accountNumber) {

        if (initialBalance < 0) {
            throw new IllegalArgumentException(
                    "Accounts with a negative balance cannot be created!");
        }
        if (accountNumber < 9999 || accountNumber > 100000){
        	throw new IllegalArgumentException(
        			"Account number needs to be 5 digit number!");
        }
        balance = initialBalance;
        this.accountNumber = accountNumber;    
    }

    /**
     * Deposits money into the BankAccount
     *
     * @param amount the amount to deposit
     */
    public void deposit(double amount) {
        if (amount < 0) {
            throw new IllegalArgumentException(
                    "Don't deposit negative amounts!");
        }
        balance = balance + amount;
    }

    
    /**
     * Withdraws money from the BankAccount
     *
     * @param amount the amount to withdraw
     */
    
    public void withdraw(double amount)  throws InsufficientFundsException {
    	if (amount < 0) {
       	 throw new IllegalArgumentException(
                    "Don't withdraw a negative amount!");
        }
        if (amount > balance) {
           throw new InsufficientFundsException(
        		   "You can't withdraw more than you have!");
        }	
        
        balance = balance - amount;
    }

    /**
     * Gets the current balance of the BankAccount
     *
     * @return the current balance
     */
    public double getBalance() {
        return balance;
    }

    /**
     * Gets the account number of the BankAccount
     * @return the account number
     */
    public int getAccountNumber() {
        return accountNumber;
    }

    /**
     * Returns a string representation this BankAccount in
     * the following format, e.g. 12345 $100.52 where 12345
     * is the account number, and 100.52 is the balance.
     */
    public String toString () {
        return "" + accountNumber + " $" + balance;
    }
}