Question

Design a class named BankAccount containing the following data field and methods.
• One double data field named balance with default
values 0.0 to denote the balance of the account.
• A no-arg constructor that creates a default bank
account.
• A constructor that creates a bank account with the
specified balance.
 throw an IllegalArgumentException when
constructing an account with a negative balance
• The accessor method for the data field.
• A method named deposit(double amount) that deposits
money into the bank account.
 throw an IllegalArgumentException when deposit a
negative amount into an account
• A method named withdraw(double amount) that withdraws
the money from the bank account.
 throw an IllegalArgumentException when
withdrawing a negative amount from an account
 define the exception class
InsufficientFundsException
 throw an InsufficientFundsException
when the balance is less than the
withdrawal amount.
• A method transfer(double amount, BankAccount other)
that transfer money from the bank account to another
account.
• A method named toString() that returns a string
description for the account.
Design two classes CheckingAccount and SavingAccount which are derived from the
class BankAccount.
• CheckingAccount will charge transaction fees. Each month there are 5 free
transactions. $3 will be deducted from the checking account for every extra
transaction. (Hint: You need to add a method to deduct the fees from the
checking account if there are more than 5 tractions in a month. You need to
modify the deposit and withdrawal method as well, and you need to add an
instance field to remember the number of transactions. You may need to define
two constants, one for number of allowed free transactions and the other for fee
per extra transaction.)
• SavingAccount will earn income at fixed interest rate. (Hint: You need to add a
method to add interest each month. Also you need to add an instance field for
interest rate.)

Write your test program to create objects and test all the methods. Your test program
should cause all three exceptions to occur and catches them all.

Answer 1

//driver class
public class Driver{

     public static void main(String []args){
     
         //declare req variables

         //create a savings acct object
         try
         {
             BankAccount accounts1=new BankAccount();
           
              System.out.print("\n********Bank Account********");
             accounts1=new BankAccount();
             //uncomment this step for throwing negatuve amount exception
             //accounts1.deposit(-1);
             accounts1.deposit(1234);
              System.out.println(accounts1);
               System.out.println("******************************");
            
               System.out.print("\n*********Savings Account*******");
              //create a sacings account object
             SavingsAccount accounts2 =new SavingsAccount (60000,21);
              System.out.println(accounts2);
              accounts2.deposit(21000);
              //uncomment this step to throw insuffieict funds exception
             // accounts2.withdraw(1000000);
               System.out.println("Balance before interest cal:" +accounts2.getBalance());
              accounts2.postInterest();
              System.out.println("Balance after interest cal:" +accounts2.getBalance());
              System.out.println("*********************************");
           
              System.out.print("\n*********Checking Account*******");
             //create a checking account obejct
             CheckingAccount accounts3 =new CheckingAccount (60000,2);
              accounts3.deposit(1000);
              accounts3.deposit(1000);
              accounts3.withdraw(1000);
             //unccooment to get negaive amount withdrawn
             // accounts3.withdraw(-12);
             System.out.println(accounts3);
              System.out.println("Balance :" +accounts3.getBalance());
               accounts3.withdraw(1000);
                System.out.println("After crosing 5 transactions");
                System.out.println("Balance :" +accounts3.getBalance());
             System.out.println("**********************************");

         }
         catch(IllegalArgumentException e)
         {
             System.out.println(e);
         }
         catch(InsufficientFundsException e)
         {
             System.out.println(e);
         }
         catch(Exception e)
         {
             System.out.println(e);
         }
     }
}

class InsufficientFundsException extends Exception{
InsufficientFundsException(String s){
super(s);
}
}
class BankAccount
{
    double balance;
  
    public BankAccount()
    {
        balance=0;
    }

    public BankAccount(double balance)throws IllegalArgumentException
    {
        // set name and balance  
        // make sure balance is not negative
        // throw exception if balance is negative
        if(balance<0)
        throw new IllegalArgumentException ("Balance cant'e be negative");
        else
        this.balance=balance;
    }

    // update balance by adding deposit amount
    // make sure deposit amount is not negative
    // throw exception if deposit is negative
    public void deposit(double amount) throws IllegalArgumentException
    {
        if(amount<0)
        throw new IllegalArgumentException ("Negative amount can't be deposited");
        else
        balance+=amount;
    }

    // update balance by subtracting withdrawal amount
    // throw exception if funds are not sufficient
    // make sure withdrawal amount is not negative
    // throw NegativeAmountException if amount is negative
    // throw InsufficientFundsException if balance < amount
    public void withdraw(double amount)   throws InsufficientFundsException, IllegalArgumentException
    {
        if(amount<0)
        throw new IllegalArgumentException ("Negative amount can't be withdrawn");
        else
        if(amount>balance)
        throw new InsufficientFundsException("No sufficient funds");
        else
        balance-=amount;
    }

    // return current balance
     public double getBalance()
     {
         return balance;
     }
   
     //transfer
     public void transfer(double amount, BankAccount other) throws InsufficientFundsException, IllegalArgumentException
     {
         this.withdraw(amount);
         other.deposit(amount);
     }

     // print bank statement including customer name
     // and current account balance
     public String toString()
     {
         return "\nBalance: "+balance;
     }
}

class CheckingAccount extends BankAccount
{
    int noOfTransactions;
    final int FREETRANS=5;
    final int FEE=3;
  
   public CheckingAccount(double balance,int noOfTransactions) throws IllegalArgumentException
    {
        // set name and balance  
        // throw exception if balance is negative
        super(balance);
        this.noOfTransactions=noOfTransactions;
    }

    public CheckingAccount()
    {
        // set name and balance  
        // throw exception if balance is negative
        super(0);
        this.noOfTransactions=0;
    }
  
    public void deductFee()
    {
        if(noOfTransactions>FREETRANS)
        balance-=5;
    }
  
    // update balance by adding deposit amount
    // make sure deposit amount is not negative
    // throw exception if deposit is negative
    public void deposit(double amount) throws IllegalArgumentException
    {
        if(amount<0)
        throw new IllegalArgumentException ("Negative amount can't be deposited");
        else
        balance+=amount;
        noOfTransactions++;
        deductFee();
    }

    // update balance by subtracting withdrawal amount
    // throw exception if funds are not sufficient
    // make sure withdrawal amount is not negative
    // throw NegativeAmountException if amount is negative
    // throw InsufficientFundsException if balance < amount
    public void withdraw(double amount)   throws InsufficientFundsException, IllegalArgumentException
    {
        if(amount<0)
        throw new IllegalArgumentException ("Negative amount can't be withdrawn");
        else
        if(amount>balance)
        throw new InsufficientFundsException("No sufficient funds");
        else
        balance-=amount;
        noOfTransactions++;
        deductFee();
    }
  
  
    // print bank statement including customer name
    // and current account balance (use printStatement from
    // the BankAccount superclass)
    // following this also print current interest rate
    public String toString()
    {
        return super.toString()+"\nNo Of Transactions: "+noOfTransactions;
    }
}
class SavingsAccount extends BankAccount
{
    double interestRate;

    public SavingsAccount(double balance,double interestRate) throws IllegalArgumentException
    {
        // set name and balance  
        // throw exception if balance is negative
        super(balance);
        this.interestRate=interestRate;
    }
  
     public SavingsAccount()
    {
        // set name and balance  
        // throw exception if balance is negative
        super(0);
        this.interestRate=0;
    }

    // post monthly interest by multiplying current balance
    // by current interest rate divided by 12 and then adding
    // result to balance by making deposit
    public void postInterest()
    {
        balance+=(getBalance()*interestRate)/12;
    }

    // print bank statement including customer name
    // and current account balance (use printStatement from
    // the BankAccount superclass)
    // following this also print current interest rate
    public String toString()
    {
        return super.toString()+"\nInterest Rate: "+interestRate;
    }
}