Double Entry Accounting

Account.java

@@ -0,0 +1,69 @@
+package accounting;
+
+import agents.Agent;
+import actions.Action;
+import contracts.Contract;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+
+class Account {
+
+    private Account(String name, AccountType accountType, Double startingBalance) {
+        this.name = name;
+        this.accountType = accountType;
+        this.balance = startingBalance;
+    }
+
+    Account(String name, AccountType accountType) {
+        this(name,accountType,0.0);
+    }
+
+    private double balance;
+
+    static void doubleEntry(Account debitAccount, Account creditAccount, double amount) {
+        debitAccount.debit(amount);
+        creditAccount.credit(amount);
+    }
+
+//    private Collateral collateralType;
+    private AccountType accountType;
+    private String name;
+
+
+    /**
+     * A Debit is a positive change for ASSET and EXPENSES accounts, and negative for the rest.
+     * @param amount the amount to debit
+     */
+    private void debit(double amount) {
+        if ((accountType==AccountType.ASSET) || (accountType==AccountType.EXPENSES)) {
+            balance += amount;
+        } else {
+            balance -= amount;
+        }
+    }
+
+    /**
+     * A Credit is a negative change for ASSET and EXPENSES accounts, and positive for the rest.
+     * @param amount the amount to credit
+     */
+    private void credit(double amount) {
+        if ((accountType==AccountType.ASSET) || (accountType==AccountType.EXPENSES)) {
+            balance -= amount;
+        } else {
+            balance += amount;
+        }
+    }
+
+    AccountType getAccountType() {
+        return accountType;
+    }
+
+    double getBalance() {
+        return balance;
+    }
+
+    String getName() {
+        return name;
+    }
+}

AccountType.java

@@ -0,0 +1,9 @@
+package accounting;
+
+public enum AccountType {
+    ASSET,
+    LIABILITY,
+    EQUITY,
+    INCOME,
+    EXPENSES
+}