OnCore-NV · Copilot · Aug 27, 2025 · Aug 27, 2025 · Aug 27, 2025
diff --git a/java/pom.xml b/java/pom.xml
@@ -45,8 +45,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.8.0</version>
                 <configuration>
-                    <source>22</source>
-                    <target>22</target>
+                    <source>17</source>
+                    <target>17</target>
                 </configuration>
             </plugin>
         </plugins>

diff --git a/java/src/main/java/dojo/supermarket/BaseReceiptPrinter.java b/java/src/main/java/dojo/supermarket/BaseReceiptPrinter.java
@@ -0,0 +1,27 @@
+package dojo.supermarket;
+
+import dojo.supermarket.model.*;
+
+import java.util.Locale;
+
+public abstract class BaseReceiptPrinter {
+
+    public abstract String printReceipt(Receipt receipt);
+
+    protected abstract String formatReceiptItem(ReceiptItem item);
+
+    protected abstract String formatDiscount(Discount discount);
+
+    protected abstract String formatTotal(Receipt receipt);
+
+    // Shared data formatting methods - keep these identical across implementations
+    protected static String presentPrice(double price) {
+        return String.format(Locale.UK, "%.2f", price);
+    }
+
+    protected static String presentQuantity(ReceiptItem item) {
+        return ProductUnit.EACH.equals(item.getProduct().getUnit())
+                ? String.format("%d", (int)item.getQuantity())
+                : String.format(Locale.UK, "%.3f", item.getQuantity());
+    }
+}
diff --git a/java/src/main/java/dojo/supermarket/HtmlReceiptDemo.java b/java/src/main/java/dojo/supermarket/HtmlReceiptDemo.java
@@ -0,0 +1,53 @@
+package dojo.supermarket;
+
+import dojo.supermarket.model.*;
+
+import java.io.FileWriter;
+import java.io.IOException;
+
+public class HtmlReceiptDemo {
+    public static void main(String[] args) throws IOException {
+        // Set up sample data with multiple items and discounts
+        SupermarketCatalog catalog = new ReceiptDemo.FakeCatalog();
+
+        Product apples = new Product("apples", ProductUnit.KILO);
+        Product toothbrush = new Product("toothbrush", ProductUnit.EACH);
+        Product toothpaste = new Product("toothpaste", ProductUnit.EACH);
+        Product cherryTomatoes = new Product("cherry tomatoes", ProductUnit.EACH);
+
+        catalog.addProduct(apples, 1.99);
+        catalog.addProduct(toothbrush, 0.99);
+        catalog.addProduct(toothpaste, 1.79);
+        catalog.addProduct(cherryTomatoes, 0.69);
+
+        Teller teller = new Teller(catalog);
+        teller.addSpecialOffer(SpecialOfferType.TEN_PERCENT_DISCOUNT, toothbrush, 10.0);
+        teller.addSpecialOffer(SpecialOfferType.TWO_FOR_AMOUNT, cherryTomatoes, 0.99);
+
+        ShoppingCart cart = new ShoppingCart();
+        cart.addItemQuantity(apples, 2.5);
+        cart.addItemQuantity(toothbrush, 3);
+        cart.addItemQuantity(toothpaste, 2);
+        cart.addItemQuantity(cherryTomatoes, 2); // Buy 2 for 0.99 deal
+
+        Receipt receipt = teller.checksOutArticlesFrom(cart);
+
+        // Generate HTML receipt
+        HtmlReceiptPrinter htmlPrinter = new HtmlReceiptPrinter();
+        String htmlReceipt = htmlPrinter.printReceipt(receipt);
+
+        // Write to file
+        try (FileWriter writer = new FileWriter("/tmp/sample_receipt.html")) {
+            writer.write(htmlReceipt);
+            System.out.println("HTML receipt written to /tmp/sample_receipt.html");
+        }
+
+        // Also show comparison
+        ReceiptPrinter textPrinter = new ReceiptPrinter();
+        System.out.println("\n=== TEXT RECEIPT ===");
+        System.out.println(textPrinter.printReceipt(receipt));
+
+        System.out.println("\n=== HTML RECEIPT ===");
+        System.out.println(htmlReceipt);
+    }
+}
diff --git a/java/src/main/java/dojo/supermarket/HtmlReceiptPrinter.java b/java/src/main/java/dojo/supermarket/HtmlReceiptPrinter.java
@@ -0,0 +1,82 @@
+package dojo.supermarket;
+
+import dojo.supermarket.model.*;
+
+public class HtmlReceiptPrinter extends BaseReceiptPrinter {
+
+    @Override
+    public String printReceipt(Receipt receipt) {
+        StringBuilder result = new StringBuilder();
+
+        result.append("<html>\n");
+        result.append("<body>\n");
+        result.append("<h1>Receipt</h1>\n");
+        result.append("<table>\n");
+
+        for (ReceiptItem item : receipt.getItems()) {
+            result.append(formatReceiptItem(item));
+        }
+
+        for (Discount discount : receipt.getDiscounts()) {
+            result.append(formatDiscount(discount));
+        }
+
+        result.append(formatTotal(receipt));
+        result.append("</table>\n");
+        result.append("</body>\n");
+        result.append("</html>\n");
+
+        return result.toString();
+    }
+
+    @Override
+    protected String formatReceiptItem(ReceiptItem item) {
+        StringBuilder result = new StringBuilder();
+        String totalPricePresentation = presentPrice(item.getTotalPrice());
+        String name = item.getProduct().getName();
+
+        result.append("<tr>");
+        result.append("<td>").append(name).append("</td>");
+        result.append("<td>").append(totalPricePresentation).append("</td>");
+        result.append("</tr>\n");
+
+        if (item.getQuantity() != 1) {
+            result.append("<tr>");
+            result.append("<td colspan='2'>");
+            result.append("  ").append(presentPrice(item.getPrice()));
+            result.append(" * ").append(presentQuantity(item));
+            result.append("</td>");
+            result.append("</tr>\n");
+        }
+
+        return result.toString();
+    }
+
+    @Override
+    protected String formatDiscount(Discount discount) {
+        String name = discount.getDescription() + "(" + discount.getProduct().getName() + ")";
+        String value = presentPrice(discount.getDiscountAmount());
+
+        StringBuilder result = new StringBuilder();
+        result.append("<tr>");
+        result.append("<td>").append(name).append("</td>");
+        result.append("<td>").append(value).append("</td>");
+        result.append("</tr>\n");
+
+        return result.toString();
+    }
+
+    @Override
+    protected String formatTotal(Receipt receipt) {
+        String name = "Total: ";
+        String value = presentPrice(receipt.getTotalPrice());
+
+        StringBuilder result = new StringBuilder();
+        result.append("<tr>");
+        result.append("<td><strong>").append(name).append("</strong></td>");
+        result.append("<td><strong>").append(value).append("</strong></td>");
+        result.append("</tr>\n");
+
+        return result.toString();
+    }
+}
diff --git a/java/src/main/java/dojo/supermarket/ReceiptDemo.java b/java/src/main/java/dojo/supermarket/ReceiptDemo.java
@@ -0,0 +1,54 @@
+package dojo.supermarket;
+
+import dojo.supermarket.model.*;
+
+public class ReceiptDemo {
+
+    static class FakeCatalog implements SupermarketCatalog {
+        private java.util.Map<String, Product> products = new java.util.HashMap<>();
+        private java.util.Map<String, Double> prices = new java.util.HashMap<>();
+
+        @Override
+        public void addProduct(Product product, double price) {
+            this.products.put(product.getName(), product);
+            this.prices.put(product.getName(), price);
+        }
+
+        @Override
+        public double getUnitPrice(Product p) {
+            return this.prices.get(p.getName());
+        }
+    }
+
+    public static void main(String[] args) {
+        // Set up sample data
+        SupermarketCatalog catalog = new FakeCatalog();
+        Product apples = new Product("apples", ProductUnit.KILO);
+        Product toothbrush = new Product("toothbrush", ProductUnit.EACH);
+        Product toothpaste = new Product("toothpaste", ProductUnit.EACH);
+
+        catalog.addProduct(apples, 1.99);
+        catalog.addProduct(toothbrush, 0.99);
+        catalog.addProduct(toothpaste, 1.79);
+
+        Teller teller = new Teller(catalog);
+        teller.addSpecialOffer(SpecialOfferType.TEN_PERCENT_DISCOUNT, toothbrush, 10.0);
+
+        ShoppingCart cart = new ShoppingCart();
+        cart.addItemQuantity(apples, 2.5);
+        cart.addItemQuantity(toothbrush, 2);
+        cart.addItemQuantity(toothpaste, 1);
+
+        Receipt receipt = teller.checksOutArticlesFrom(cart);
+
+        // Print text receipt
+        ReceiptPrinter textPrinter = new ReceiptPrinter();
+        System.out.println("=== TEXT RECEIPT ===");
+        System.out.println(textPrinter.printReceipt(receipt));
+
+        // Print HTML receipt
+        HtmlReceiptPrinter htmlPrinter = new HtmlReceiptPrinter();
+        System.out.println("\n=== HTML RECEIPT ===");
+        System.out.println(htmlPrinter.printReceipt(receipt));
+    }
+}
diff --git a/...java/dojo/supermarket/ReceiptPrinter.java → ...java/dojo/supermarket/ReceiptPrinter.java b/...java/dojo/supermarket/ReceiptPrinter.java → ...java/dojo/supermarket/ReceiptPrinter.java
@@ -4,7 +4,7 @@
 
 import java.util.Locale;
 
-public class ReceiptPrinter {
+public class ReceiptPrinter extends BaseReceiptPrinter {
 
     private final int columns;
 
@@ -16,22 +16,38 @@ public ReceiptPrinter(int columns) {
         this.columns = columns;
     }
 
+    @Override
     public String printReceipt(Receipt receipt) {
         StringBuilder result = new StringBuilder();
         for (ReceiptItem item : receipt.getItems()) {
-            String receiptItem = presentReceiptItem(item);
+            String receiptItem = formatReceiptItem(item);
             result.append(receiptItem);
         }
         for (Discount discount : receipt.getDiscounts()) {
-            String discountPresentation = presentDiscount(discount);
+            String discountPresentation = formatDiscount(discount);
             result.append(discountPresentation);
         }
 
         result.append("\n");
-        result.append(presentTotal(receipt));
+        result.append(formatTotal(receipt));
         return result.toString();
     }
 
+    @Override
+    protected String formatReceiptItem(ReceiptItem item) {
+        return presentReceiptItem(item);
+    }
+
+    @Override
+    protected String formatDiscount(Discount discount) {
+        return presentDiscount(discount);
+    }
+
+    @Override
+    protected String formatTotal(Receipt receipt) {
+        return presentTotal(receipt);
+    }
+
     private String presentReceiptItem(ReceiptItem item) {
         String totalPricePresentation = presentPrice(item.getTotalPrice());
         String name = item.getProduct().getName();
@@ -69,13 +85,11 @@ private String formatLineWithWhitespace(String name, String value) {
         return line.toString();
     }
 
-    private static String presentPrice(double price) {
-        return String.format(Locale.UK, "%.2f", price);
+    protected static String presentPrice(double price) {
+        return BaseReceiptPrinter.presentPrice(price);
     }
 
-    private static String presentQuantity(ReceiptItem item) {
-        return ProductUnit.EACH.equals(item.getProduct().getUnit())
-                ? String.format("%d", (int)item.getQuantity())
-                : String.format(Locale.UK, "%.3f", item.getQuantity());
+    protected static String presentQuantity(ReceiptItem item) {
+        return BaseReceiptPrinter.presentQuantity(item);
     }
 }