feat: implement BusinessCheckingAccount and MoneyOrder classes

Author: ethanhillman

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BusinessCheckingAccount.java

@@ -0,0 +1,29 @@
+package com.codedifferently.lesson17.bank;
+import java.util.Set;
+
+public class BusinessCheckingAccount extends CheckingAccount {
+
+    public BusinessCheckingAccount(String accountNumber, Set<Customer> owners) {
+        super(accountNumber, owners);
+        validateBusinessOwners();
+    }
+
+    public BusinessCheckingAccount(String accountNumber, Set<Customer> owners, double initialBalance) {
+        super(accountNumber, owners, initialBalance);
+        validateBusinessOwners();
+    }
+
+    private void validateBusinessOwners() {
+        boolean hasBusinessOwner = getOwners().stream()
+            .anyMatch(Customer::isBusiness);
+
+        if(!hasBusinessOwner) { 
+            throw new IllegalArgumentException("At least one owner must be a business.");
+        }
+    }
+
+
+    public String getAccountType() {
+        return "Business Checking Account";
+    }
+}

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/MoneyOrder.java

@@ -0,0 +1,47 @@
+package com.codedifferently.lesson17.bank;
+
+public class MoneyOrder {
+    private final String moneyOrderNumber;
+    private final String payee;
+    private final String sourceAccountNumber;
+    private final Double amount;
+    private Boolean deposited = false;
+
+    public MoneyOrder(String moneyOrderNumber, String payee, String sourceAccountNumber, Double amount) { 
+        if (amount <= 0) {
+            throw new IllegalArgumentException("Invalid amount");
+        }
+        this.moneyOrderNumber = moneyOrderNumber;
+        this.payee = payee;
+        this.sourceAccountNumber = sourceAccountNumber;
+        this.amount = amount;
+    }
+
+    public void depositFunds(CheckingAccount account) {
+        if (deposited) {
+            throw new IllegalStateException("Money order " + moneyOrderNumber + " has already been deposited.");
+        }
+        account.deposit(amount);
+        deposited = true;
+    }
+
+    public String getMoneyOrderNumber() {
+        return moneyOrderNumber;
+    }
+
+    public String getPayee() {
+        return payee;
+    }
+
+    public String getSourceAccountNumber() {
+        return sourceAccountNumber;
+    }
+
+    public Double getAmount() {
+        return amount;
+    }
+
+    public Boolean getDeposited() {
+        return deposited;
+    }
+}