Added "controllers" and repository classes to communicate with database to maintain code cleanliness

Author: Mohaned Atef

Monolithic-Ecommerce/src/main/java/com/iluwatar/monolithic/controller/OrderCon.java

@@ -0,0 +1,44 @@
+package com.iluwatar.monolithic.controller;
+
+import com.iluwatar.monolithic.model.User;
+import com.iluwatar.monolithic.model.Orders;
+import com.iluwatar.monolithic.model.Products;
+import com.iluwatar.monolithic.repository.OrderRepo;
+import com.iluwatar.monolithic.repository.ProductRepo;
+import com.iluwatar.monolithic.repository.UserRepo;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class OrderCon {
+    @Autowired
+    private OrderRepo orderRepository;
+
+    @Autowired
+    private UserRepo userRepository;
+
+    @Autowired
+    private ProductRepo productRepository;
+
+    public Orders placeOrder(Long userId, Long productId, Integer quantity) {
+        User user = userRepository.findById(userId).orElse(null);
+        if (user == null) {
+            throw new RuntimeException("User not found");
+        }
+
+        Products product = productRepository.findById(productId).orElse(null);
+        if (product == null) {
+            throw new RuntimeException("Product not found");
+}
+
+        if (product.getStock() < quantity) {
+            throw new RuntimeException("Not enough stock");
+        }
+
+        product.setStock(product.getStock() - quantity);
+        productRepository.save(product);
+
+        Orders order = new Orders(null, user, product, quantity, product.getPrice() * quantity);
+        return orderRepository.save(order);
+    }
+}

Monolithic-Ecommerce/src/main/java/com/iluwatar/monolithic/controller/ProductCon.java

@@ -0,0 +1,22 @@
+package com.iluwatar.monolithic.controller;
+
+import com.iluwatar.monolithic.model.Products;
+import com.iluwatar.monolithic.repository.ProductRepo;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+public class ProductCon {
+    @Autowired
+    private ProductRepo productRepository;
+
+    public Products addProduct(Products product) {
+        return productRepository.save(product);
+    }
+
+    public List<Products> getAllProducts() {
+        return productRepository.findAll();
+    }
+}

Monolithic-Ecommerce/src/main/java/com/iluwatar/monolithic/controller/UserCon.java

@@ -0,0 +1,16 @@
+package com.iluwatar.monolithic.controller;
+
+import com.iluwatar.monolithic.model.User;
+import com.iluwatar.monolithic.repository.UserRepo;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class UserCon {
+    @Autowired
+    private UserRepo userRepository;
+
+    public User registerUser(User user) {
+        return userRepository.save(user);
+    }
+}

Monolithic-Ecommerce/src/main/java/com/iluwatar/monolithic/model/Orders.java

@@ -6,21 +6,26 @@
 import jakarta.persistence.Id;
 import jakarta.persistence.ManyToOne;
 import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.AllArgsConstructor;
+
 
 /**
  * Represents a Database in which Orders are stored.
  */
 @Entity
 @Data
+@NoArgsConstructor
+@AllArgsConstructor
 public class Orders {
     @Id
-    @GeneratedValue(strategy = GenerationType.IDENTITY) // Auto-increment ID
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
 
-    @ManyToOne // Relationship with User
+    @ManyToOne
     private User user;
 
-    @ManyToOne // Relationship with Product
+    @ManyToOne
     private Products product;
 
     private Integer quantity;

Monolithic-Ecommerce/src/main/java/com/iluwatar/monolithic/model/Products.java

@@ -4,16 +4,21 @@
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
+
 import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.AllArgsConstructor;
 
 /**
- * Represents a databse of products .
+ * Represents a database of products.
  */
 @Entity
 @Data
+@NoArgsConstructor
+@AllArgsConstructor
 public class Products {
     @Id
-    @GeneratedValue(strategy = GenerationType.IDENTITY) // Generated Auto-increment ID
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
 
     private String name;
@@ -24,3 +29,4 @@ public class Products {
 
     private Integer stock;
 }
+

Monolithic-Ecommerce/src/main/java/com/iluwatar/monolithic/model/User.java

@@ -5,22 +5,28 @@
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
+
 import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.AllArgsConstructor;
 
 /**
- * Represents a User entity for the database to interact with the rest of the project.
+ * Represents a Product entity for the database.
  */
+
 @Entity
 @Data
+@NoArgsConstructor
+@AllArgsConstructor
 public class User {
     @Id
-    @GeneratedValue(strategy = GenerationType.IDENTITY) // Generated Auto-increment ID
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
 
     private String name;
 
-    @Column(unique = true) // Ensures unique emails
+    @Column(unique = true)
     private String email;
 
     private String password;
-}
+}

Monolithic-Ecommerce/src/main/java/com/iluwatar/monolithic/repository/OrderRepo.java

@@ -0,0 +1,7 @@
+package com.iluwatar.monolithic.repository;
+
+import com.iluwatar.monolithic.model.Orders;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface OrderRepo extends JpaRepository<Orders, Long> {
+}

Monolithic-Ecommerce/src/main/java/com/iluwatar/monolithic/repository/ProductRepo.java

@@ -0,0 +1,7 @@
+package com.iluwatar.monolithic.repository;
+
+import com.iluwatar.monolithic.model.Products;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface ProductRepo extends JpaRepository<Products, Long> {
+}

Monolithic-Ecommerce/src/main/java/com/iluwatar/monolithic/repository/UserRepo.java

@@ -0,0 +1,8 @@
+package com.iluwatar.monolithic.repository;
+
+import com.iluwatar.monolithic.model.User;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface UserRepo extends JpaRepository<User, Long> {
+    User findByEmail(String email);
+}