Reapply "fix: Refactor Layered Architecture pattern iluwatar#2936"

This reverts commit 54aee49.

layers/src/main/java/com/iluwatar/layers/Runner.java

@@ -32,6 +32,10 @@
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.domain.EntityScan;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
 import org.springframework.stereotype.Component;
 import service.CakeBakingService;
 import view.CakeViewImpl;
@@ -44,6 +48,8 @@
  * It uses the CakeBakingService to save new layers and toppings and to bake new cakes.
  * It also handles exceptions that might occur during the cake baking process.</p>
  */
+@EntityScan(basePackages = "entity")
+@ComponentScan(basePackages = {"com.iluwatar.layers", "service", "dto", "exception", "view", "dao"})
 @Component
 @Slf4j
 public class Runner implements CommandLineRunner {
@@ -64,6 +70,10 @@ public void run(String... args) {
     cakeView.render();
   }
 
+  public static void main(String[] args) {
+    SpringApplication.run(Runner.class, args);
+  }
+
   /**
    * Initializes the example data.
    */

layers/src/main/java/dto/CakeInfo.java

@@ -26,22 +26,21 @@
 package dto;
 
 import java.util.List;
-import java.util.Optional;
 
 /**
  * DTO for cakes.
  */
 public class CakeInfo {
 
-  public final Optional<Long> id;
+  public final Long id;
   public final CakeToppingInfo cakeToppingInfo;
   public final List<CakeLayerInfo> cakeLayerInfos;
 
   /**
    * Constructor.
    */
   public CakeInfo(Long id, CakeToppingInfo cakeToppingInfo, List<CakeLayerInfo> cakeLayerInfos) {
-    this.id = Optional.of(id);
+    this.id = id;
     this.cakeToppingInfo = cakeToppingInfo;
     this.cakeLayerInfos = cakeLayerInfos;
   }
@@ -50,7 +49,7 @@ public CakeInfo(Long id, CakeToppingInfo cakeToppingInfo, List<CakeLayerInfo> ca
    * Constructor.
    */
   public CakeInfo(CakeToppingInfo cakeToppingInfo, List<CakeLayerInfo> cakeLayerInfos) {
-    this.id = Optional.empty();
+    this.id = null;
     this.cakeToppingInfo = cakeToppingInfo;
     this.cakeLayerInfos = cakeLayerInfos;
   }
@@ -66,7 +65,7 @@ public int calculateTotalCalories() {
 
   @Override
   public String toString() {
-    return String.format("CakeInfo id=%d topping=%s layers=%s totalCalories=%d", id.orElse(-1L),
+    return String.format("CakeInfo id=%d topping=%s layers=%s totalCalories=%d", id,
         cakeToppingInfo, cakeLayerInfos, calculateTotalCalories());
   }
 }

layers/src/main/java/dto/CakeLayerInfo.java

@@ -25,22 +25,20 @@
 
 package dto;
 
-import java.util.Optional;
-
 /**
  * DTO for cake layers.
  */
 public class CakeLayerInfo {
 
-  public final Optional<Long> id;
+  public final Long id;
   public final String name;
   public final int calories;
 
   /**
    * Constructor.
    */
   public CakeLayerInfo(Long id, String name, int calories) {
-    this.id = Optional.of(id);
+    this.id = id;
     this.name = name;
     this.calories = calories;
   }
@@ -49,13 +47,13 @@ public CakeLayerInfo(Long id, String name, int calories) {
    * Constructor.
    */
   public CakeLayerInfo(String name, int calories) {
-    this.id = Optional.empty();
+    this.id = null;
     this.name = name;
     this.calories = calories;
   }
 
   @Override
   public String toString() {
-    return String.format("CakeLayerInfo id=%d name=%s calories=%d", id.orElse(-1L), name, calories);
+    return String.format("CakeLayerInfo id=%d name=%s calories=%d", id, name, calories);
   }
 }

layers/src/main/java/dto/CakeToppingInfo.java

@@ -25,23 +25,20 @@
 
 package dto;
 
-
-import java.util.Optional;
-
 /**
  * DTO for cake toppings.
  */
 public class CakeToppingInfo {
 
-  public final Optional<Long> id;
+  public final Long id;
   public final String name;
   public final int calories;
 
   /**
    * Constructor.
    */
   public CakeToppingInfo(Long id, String name, int calories) {
-    this.id = Optional.of(id);
+    this.id = id;
     this.name = name;
     this.calories = calories;
   }
@@ -50,14 +47,14 @@ public CakeToppingInfo(Long id, String name, int calories) {
    * Constructor.
    */
   public CakeToppingInfo(String name, int calories) {
-    this.id = Optional.empty();
+    this.id = null;
     this.name = name;
     this.calories = calories;
   }
 
   @Override
   public String toString() {
-    return String.format("CakeToppingInfo id=%d name=%s calories=%d", id.orElse(-1L), name,
+    return String.format("CakeToppingInfo id=%d name=%s calories=%d", id, name,
         calories);
   }
 }