Phase III

-   Added:
    -   AccountInterface
    -   CheckingAccount
    -   SavingsAccount
-   Converted Account to abstract class
-   All instance variables are validated via exception handling

src/bankAcctApp/CheckingAccount.java

@@ -0,0 +1,42 @@
+/* Phase III */
+
+package bankAcctApp;
+
+// Class representing checking accounts
+public class CheckingAccount extends Account {
+
+    // Overridden method for withdrawals in checking accounts
+    @Override
+    public void withdrawal(double amount) {
+        double newBalance = getBalance() - amount - getSvcFee(); // Deduct amount and service fee
+        if (newBalance < 0) { // Check for overdraft
+            newBalance -= getOverDraftFee(); // Apply overdraft fee if balance is negative
+        }
+        setBalance(newBalance); // Update balance
+    }
+
+    // Overridden method for deposits in checking accounts
+    @Override
+    public void deposit(double amount) {
+        setBalance(getBalance() + amount - getSvcFee()); // Add amount and deduct service fee
+    }
+
+    // Overridden method for applying accrued interest in checking accounts
+    @Override
+    public double applyAccruedInterest(String transactionDate) {
+        double interest = 0.0;
+    	if (getBalance() <= 0.0) { // Ensure balance is positive for interest accrual
+            System.out.println("This account has an insufficient balance for interest to apply.");
+        } else {
+	        interest = getBalance() * (getInterestRate() / 100); // Calculate interest
+	        setBalance(getBalance() + interest); // Add interest to the balance
+	        logTransaction(transactionDate, "INT", interest); // Log the interest transaction
+        }
+    	return interest;
+    }
+    // Implementation of balance() method from AccountInterface
+    @Override
+    public double balance() {
+        return getBalance(); // Return the current balance
+    }
+}