Question

Java - In NetBeans IDE:

•Design an abstract class called BankAccount which stores the balance.

–Implement a constructor that takes the balance (float).

–Provide abstract methods deposit(amount) and withdraw(amount)

•Design a class called SavingsAccount which extends BankAccount.

–Implement a constructor that takes the balance as input.

–It should store a boolean flag active. If the balance at any point falls below $25, it sets the active flag to false. It should NOT allow the balance to fall below $0.

–If the active flag is false, no more withdraws can be made until deposits are made to bring the account back up to $25. An error message should be printed when withdraws fail.

–Implement the deposit and withdraw methods. They should print at the end the amount deposited/withdrew and the new balance.

•Write a main method that asks the user for the starting balance and creates a SavingsAccount object. It asks the user whether they want to deposit or withdraw until they choose to exit. Use D, W, and E for the menu options to choose deposit withdraw or exit.

Answer 1

//BankAccount.java

public abstract class BankAccount {
  
   private float balance;
  
   // constructor
   public BankAccount(float balance)
   {
       this.balance = balance;
   }
  
   // return the balance of the account
   public float getBalance()
   {
       return balance;
   }
  
   // set the balance of the account
   public void setBalance(float balance)
   {
       this.balance = balance;
   }
  
   // abstract methods
   public abstract void deposit(float amount);
   public abstract void withdraw(float amount);

}

//end of BankAccount.java

// SavingsAccount.java

public class SavingsAccount extends BankAccount{
  
   private boolean active;
  
   // constructor
   public SavingsAccount(float balance)
   {
       super(balance); // call BankAccount's constructor
       if(balance < 25)
           active = false;
       else
           active = true;
   }

   // method to deposit an amount
   @Override
   public void deposit(float amount) {
       System.out.printf("Amount to deposit: $%.2f",amount);
       if(amount > 0) // amount is valid
       {
           setBalance(getBalance()+amount);
          
           if(!active && getBalance() > 25)
               active = true;
       }else // invalid amount
           System.out.print("\nAmount to deposit > 0");
       System.out.printf("\nUpdated balance: $%.2f",getBalance());
   }

   // method to withdraw amount
   @Override
   public void withdraw(float amount) {
      
       System.out.printf("Amount to withdraw: %.2f",amount);
       if(active) // check if account is active
       {
           // check if withdrawal can be made
           if(amount > getBalance())
           {
               System.out.print("\nInsufficient funds in the account");
           }else
           {
               setBalance(getBalance()-amount); // withdraw the amount
               if(getBalance() < 25) // set active to false if balance < 25
                   active = false;
           }
       }else // inactive account
           System.out.print("\nCannot withdraw from an inactive account. Deposit amount to bring the account back up to $25 and activate it");
       System.out.printf("\nUpdated balance: $%.2f",getBalance());
   }
  
}

//end of SavingsAccount.java

//BankAccountDriver.java

public class BankAccountDriver{
  
   public static void main(String[] args)
   {
       float balance, amount;
       String choice;
       Scanner scan = new Scanner(System.in);
       SavingsAccount account;
       // input of starting balance
       System.out.print("Enter the starting balance: ");
       balance = scan.nextFloat();
       // validate balance and re-prompt until valid
       while(balance < 0)
       {
           System.out.print("Balance cannot be negative. Re-enter: ");
           balance = scan.nextFloat();
       }
      
       account = new SavingsAccount(balance); // create an account
      
       scan.nextLine();
       // loop that continues till the user wants
       do
       {
           // display the menu
           System.out.println("\nD - Deposit\nW - Withdraw\nE- Exit");
           System.out.print("Select an option(D/W/E): ");
           choice = scan.nextLine(); // input the menu choice
          
           // validate menu choice and re-prompt until valid
           while(!choice.equalsIgnoreCase("D") && !choice.equalsIgnoreCase("W") && !choice.equalsIgnoreCase("E"))
           {
               System.out.print("Invalid option. Re-enter: ");
               choice = scan.nextLine();
           }
          
           // deposit an amount
           if(choice.equalsIgnoreCase("D"))
           {
               System.out.print("Enter the amount to deposit: ");
               amount = scan.nextFloat();
               account.deposit(amount);
               scan.nextLine();
           }
           else if(choice.equalsIgnoreCase("W")) // withdraw an amount
           {
               System.out.print("Enter the amount to withdraw: ");
               amount = scan.nextFloat();
               account.withdraw(amount);
               scan.nextLine();
           }
       System.out.println();
          
       }while(!choice.equalsIgnoreCase("E"));
      
       scan.close();
      
   }
}

//end of BankAccountDriver.java

Output: