Merge data transfer object examples (#1635)

* #1617 merge dto pattern examples

* #1617 update license headers

Co-authored-by: Subhrodip Mohanta <subhrodipmohanta@gmail.com>

data-transfer-object/src/main/java/com/iluwatar/datatransfer/App.java

@@ -23,7 +23,13 @@
 
 package com.iluwatar.datatransfer;
 
+import com.iluwatar.datatransfer.customer.CustomerDto;
+import com.iluwatar.datatransfer.customer.CustomerResource;
+import com.iluwatar.datatransfer.product.Product;
+import com.iluwatar.datatransfer.product.ProductDto;
+import com.iluwatar.datatransfer.product.ProductResource;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -32,11 +38,17 @@ import org.slf4j.LoggerFactory;
  * The Data Transfer Object pattern is a design pattern in which an data transfer object is used to
  * serve related information together to avoid multiple call for each piece of information.
  *
- * <p>In this example, ({@link App}) as as customer details consumer i.e. client to
- * request for customer details to server.
+ * <p>In the first example, {@link App} is a customer details consumer i.e. client to
+ * request for customer details to server. {@link CustomerResource} act as server to serve customer
+ * information. {@link CustomerDto} is data transfer object to share customer information.
+ *
+ * <p>In the second example, {@link App} is a product details consumer i.e. client to
+ * request for product details to server. {@link ProductResource} acts as server to serve
+ * product information. {@link ProductDto} is data transfer object to share product information.
+ *
+ * <p>The pattern implementation is a bit different in each of the examples. The first can be
+ * thought as a traditional example and the second is an enum based implementation.
  *
- * <p>CustomerResource ({@link CustomerResource}) act as server to serve customer information. And
- * The CustomerDto ({@link CustomerDto} is data transfer object to share customer information.
  */
 public class App {
 
@@ -48,6 +60,8 @@ public class App {
    * @param args program argument.
    */
   public static void main(String[] args) {
+
+    // Example 1: Customer DTO
     var customerOne = new CustomerDto("1", "Kelly", "Brown");
     var customerTwo = new CustomerDto("2", "Alfonso", "Bass");
     var customers = new ArrayList<>(List.of(customerOne, customerTwo));
@@ -72,6 +86,53 @@ public class App {
     customerResource.save(customerThree);
     allCustomers = customerResource.getAllCustomers();
     printCustomerDetails(allCustomers);
+
+    // Example 2: Product DTO
+    Product tv =
+        new Product().setId(1L).setName("TV").setSupplier("Sony").setPrice(1000D).setCost(1090D);
+    Product microwave =
+        new Product()
+            .setId(2L)
+            .setName("microwave")
+            .setSupplier("Delonghi")
+            .setPrice(1000D)
+            .setCost(1090D);
+    Product refrigerator =
+        new Product()
+            .setId(3L)
+            .setName("refrigerator")
+            .setSupplier("Botsch")
+            .setPrice(1000D)
+            .setCost(1090D);
+    Product airConditioner =
+        new Product()
+            .setId(4L)
+            .setName("airConditioner")
+            .setSupplier("LG")
+            .setPrice(1000D)
+            .setCost(1090D);
+    List<Product> products =
+        new ArrayList<>(Arrays.asList(tv, microwave, refrigerator, airConditioner));
+    ProductResource productResource = new ProductResource(products);
+
+    LOGGER.info(
+        "####### List of products including sensitive data just for admins: \n {}",
+        Arrays.toString(productResource.getAllProductsForAdmin().toArray()));
+    LOGGER.info(
+        "####### List of products for customers: \n {}",
+        Arrays.toString(productResource.getAllProductsForCustomer().toArray()));
+
+    LOGGER.info("####### Going to save Sony PS5 ...");
+    ProductDto.Request.Create createProductRequestDto =
+        new ProductDto.Request.Create()
+            .setName("PS5")
+            .setCost(1000D)
+            .setPrice(1220D)
+            .setSupplier("Sony");
+    productResource.save(createProductRequestDto);
+    LOGGER.info(
+        "####### List of products after adding PS5: {}",
+        Arrays.toString(productResource.getProducts().toArray()));
   }
 
   private static void printCustomerDetails(List<CustomerDto> allCustomers) {