Multi Currency Money [springframeworkguru#25. Implementing Currency inside abstract class Money]

Author: gechulim

src/test/java/guru/springframework/Dollar.java

@@ -1,11 +1,11 @@
 package guru.springframework;
 
-public class Dollar extends Money{
-    public Dollar(int amount) {
-        this.amount = amount;
+public class Dollar extends Money {
+    public Dollar(int amount, String currency) {
+        super(amount, currency);
     }
 
     public Money times(int multiplier) {
-        return new Dollar(this.amount * multiplier);
+        return Money.dollar(this.amount * multiplier);
     }
 }

src/test/java/guru/springframework/Franc.java

@@ -1,12 +1,12 @@
 package guru.springframework;
 
 public class Franc extends Money {
-    public Franc(int amount) {
-        this.amount = amount;
+    public Franc(int amount, String currency) {
+        super(amount, currency);
     }
 
     public Money times(int multiplier) {
-        return new Franc(this.amount * multiplier);
+        return Money.franc(this.amount * multiplier);
     }
 
 }

src/test/java/guru/springframework/Money.java

@@ -2,15 +2,26 @@
 
 public abstract class Money {
     protected int amount;
+    protected String currency;
+
+
+    public Money(int amount, String currency) {
+        this.amount = amount;
+        this.currency = currency;
+    }
+
+    protected String currency() {
+        return currency;
+    }
 
     public abstract Money times(int multiplier);
 
     public static Money dollar(int amount) {
-        return new Dollar(amount);
+        return new Dollar(amount, "USD");
     }
 
     public static Money franc(int amount) {
-        return new Franc(amount);
+        return new Franc(amount, "CHF");
     }
 
     public boolean equals(Object o) {

src/test/java/guru/springframework/MoneyTest.java

@@ -33,4 +33,10 @@ void testEqualityFranc() {
         assertNotEquals(Money.franc(5), Money.franc(8));
         assertNotEquals(Money.franc(5), Money.dollar(5));
     }
+
+    @Test
+    void testCurrency() {
+        assertEquals("USD", Money.dollar(1).currency());
+        assertEquals("CHF", Money.franc(1).currency());
+    }
 }