Question

• 1. Write a java program using methods to find the information about a account holder at bank.

c) For every transaction make sure make use of his account balance.

Answer 1

// File: BankAccountTest2.java
class BankAccount
{

    private String accountNum;     // the account number
    private double balance;        // the amount on deposit

    public BankAccount(String acctNum, double initialBalance)
    {
        accountNum = acctNum;
        balance = initialBalance;
    }

    public void deposit(double amount)             // note "mutator" method
    {
        double newBalance = balance + amount;
        balance = newBalance;                      // modifies instance var                        
    }

    public void withdraw(double amount)            // note "mutator" method
    {
        double newBalance = balance - amount;
        balance = newBalance;                   // modifies instance var
    }

    public String getAccount()              // note "accessor" method
    {
        return accountNum;                // returns value of instance var
    }

    public double getBalance()             // note "accessor" method
    {
        return balance;                  // returns value of instance var
    }

    public void transferFundsA(BankAccount destination, double amount)
    {
        destination.balance = destination.balance + amount;
        // note explicit use of this to reference instance variables of the 
        // object for which the method was called
        this.balance = this.balance - amount;
    }

    public void transferFundsB(BankAccount destination, double amount)
    {
        destination.deposit(amount);    // deposit to "destination" account
        this.withdraw(amount);           // withdraw from this account
    }
}
//******************** end of BankAccount class definition ********************

/** A class to test the BankAccount2 class  */

public class BankAccountTest2
{

    public static void main(String[] args)
    {
        BankAccount first = new BankAccount("1111111", 20000);
        BankAccount second = new BankAccount("2222222", 30000);

        System.out.printf("Account #%s has initial balance of $%.2f%n",
                first.getAccount(), first.getBalance());

        System.out.printf("Account #%s has initial balance of $%.2f%n",
                second.getAccount(), second.getBalance());

        first.transferFundsA(second, 5000);

        System.out.println("\nAfter \"first.transferFunds(second, 5000)\" ...");
        System.out.printf("Account #%s has new balance of $%.2f%n",
                first.getAccount(), first.getBalance());

        System.out.printf("Account #%s has new balance of $%.2f%n",
                second.getAccount(), second.getBalance());

        second.transferFundsB(first, 10000);

        System.out.println("\nAfter \"second.transferFunds(first,10000)\" ...");
        System.out.printf("Account #%s has new balance of $%.2f%n",
                first.getAccount(), first.getBalance());

        System.out.printf("Account #%s has new balance of $%.2f%n",
                second.getAccount(), second.getBalance());
    }
}





/**************************** OR ***********************************/


public class AccountTesting implements Runnable {
        private Account acct = new Account();
        public static void main(String[] args) {
                AccountTesting r = new AccountTesting();
                Thread one = new Thread(r);
                Thread two = new Thread(r);
                one.setName("Ranjeet");
                two.setName("Reema");
                one.start();
                two.start();
        }
        @Override
        public void run() {
                for (int x = 0; x < 5; x++) {
                        makeWithdrawal(10);
                        if (acct.getBalance() < 0) {
                                System.out.println("account is overdrawn!");
                        }
                }
        }
        private void makeWithdrawal(int amt) {
                if (acct.getBalance() >= amt) {
                        System.out.println(Thread.currentThread().getName() + " is going to withdraw");
                        try {
                                Thread.sleep(100);
                        } catch (InterruptedException ex) {
                        }
                        acct.withdraw(amt);
                        System.out.println(Thread.currentThread().getName() + " completes the withdrawal");
                } else {
                        System.out.println("Not enough in account for " + Thread.currentThread().getName() + " to withdraw " + acct.getBalance());
                }
        }
}

class Account {
        private int balance = 50;
        public int getBalance() {
        return balance;
        }
        public void withdraw(int amount) {
        balance = balance - amount;
        }
}