docs: data transfer object + refactor

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

@@ -67,15 +67,15 @@ public class App {
 
     var customerResource = new CustomerResource(customers);
 
-    LOGGER.info("All customers:-");
-    var allCustomers = customerResource.getAllCustomers();
+    LOGGER.info("All customers:");
+    var allCustomers = customerResource.customers();
     printCustomerDetails(allCustomers);
 
     LOGGER.info("----------------------------------------------------------");
 
     LOGGER.info("Deleting customer with id {1}");
-    customerResource.delete(customerOne.getId());
-    allCustomers = customerResource.getAllCustomers();
+    customerResource.delete(customerOne.id());
+    allCustomers = customerResource.customers();
     printCustomerDetails(allCustomers);
 
     LOGGER.info("----------------------------------------------------------");
@@ -83,7 +83,7 @@ public class App {
     LOGGER.info("Adding customer three}");
     var customerThree = new CustomerDto("3", "Lynda", "Blair");
     customerResource.save(customerThree);
-    allCustomers = customerResource.getAllCustomers();
+    allCustomers = customerResource.customers();
     printCustomerDetails(allCustomers);
 
     // Example 2: Product DTO
@@ -131,10 +131,10 @@ public class App {
     productResource.save(createProductRequestDto);
     LOGGER.info(
         "####### List of products after adding PS5: {}",
-        Arrays.toString(productResource.getProducts().toArray()));
+        Arrays.toString(productResource.products().toArray()));
   }
 
   private static void printCustomerDetails(List<CustomerDto> allCustomers) {
-    allCustomers.forEach(customer -> LOGGER.info(customer.getFirstName()));
+    allCustomers.forEach(customer -> LOGGER.info(customer.firstName()));
   }
 }

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

@@ -33,11 +33,4 @@ import lombok.RequiredArgsConstructor;
  *
  * <p>Dto will not have any business logic in it.
  */
-@Getter
-@RequiredArgsConstructor
-public class CustomerDto {
-  private final String id;
-  private final String firstName;
-  private final String lastName;
-
-}
+public record CustomerDto(String id, String firstName, String lastName) {}

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

@@ -25,25 +25,14 @@
 package com.iluwatar.datatransfer.customer;
 
 import java.util.List;
+import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 
 /**
  * The resource class which serves customer information. This class act as server in the demo. Which
  * has all customer details.
  */
-@RequiredArgsConstructor
-public class CustomerResource {
-  private final List<CustomerDto> customers;
-
-  /**
-   * Get all customers.
-   *
-   * @return : all customers in list.
-   */
-  public List<CustomerDto> getAllCustomers() {
-    return customers;
-  }
-
+public record CustomerResource(List<CustomerDto> customers) {
   /**
    * Save new customer.
    *
@@ -59,6 +48,6 @@ public class CustomerResource {
    * @param customerId delete customer with id {@code customerId}
    */
   public void delete(String customerId) {
-    customers.removeIf(customer -> customer.getId().equals(customerId));
+    customers.removeIf(customer -> customer.id().equals(customerId));
   }
-}
+}

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

@@ -30,16 +30,13 @@ import java.util.List;
  * The resource class which serves product information. This class act as server in the demo. Which
  * has all product details.
  */
-public class ProductResource {
-  private final List<Product> products;
-
+public record ProductResource(List<Product> products) {
   /**
    * Initialise resource with existing products.
    *
    * @param products initialize resource with existing products. Act as database.
    */
-  public ProductResource(final List<Product> products) {
-    this.products = products;
+  public ProductResource {
   }
 
   /**
@@ -49,11 +46,11 @@ public class ProductResource {
    */
   public List<ProductDto.Response.Private> getAllProductsForAdmin() {
     return products
-            .stream()
-            .map(p -> new ProductDto.Response.Private().setId(p.getId()).setName(p.getName())
-                    .setCost(p.getCost())
-                    .setPrice(p.getPrice()))
-            .toList();
+        .stream()
+        .map(p -> new ProductDto.Response.Private().setId(p.getId()).setName(p.getName())
+            .setCost(p.getCost())
+            .setPrice(p.getPrice()))
+        .toList();
   }
 
   /**
@@ -63,10 +60,10 @@ public class ProductResource {
    */
   public List<ProductDto.Response.Public> getAllProductsForCustomer() {
     return products
-            .stream()
-            .map(p -> new ProductDto.Response.Public().setId(p.getId()).setName(p.getName())
-                    .setPrice(p.getPrice()))
-            .toList();
+        .stream()
+        .map(p -> new ProductDto.Response.Public().setId(p.getId()).setName(p.getName())
+            .setPrice(p.getPrice()))
+        .toList();
   }
 
   /**
@@ -76,12 +73,12 @@ public class ProductResource {
    */
   public void save(ProductDto.Request.Create createProductDto) {
     products.add(Product.builder()
-            .id((long) (products.size() + 1))
-            .name(createProductDto.getName())
-            .supplier(createProductDto.getSupplier())
-            .price(createProductDto.getPrice())
-            .cost(createProductDto.getCost())
-            .build());
+        .id((long) (products.size() + 1))
+        .name(createProductDto.getName())
+        .supplier(createProductDto.getSupplier())
+        .price(createProductDto.getPrice())
+        .cost(createProductDto.getCost())
+        .build());
   }
 
   /**
@@ -89,7 +86,8 @@ public class ProductResource {
    *
    * @return : all the products entity that stored in the products list
    */
-  public List<Product> getProducts() {
+  @Override
+  public List<Product> products() {
     return products;
   }
 }