Третья лабораторная работа. Создана сущность CountProduct для подсчета товаров в корзине вместо обозначения связи многие ко многим через collectionTable.

backend/lab/build.gradle

@@ -17,9 +17,10 @@ dependencies {
 
 	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
 	implementation 'com.h2database:h2:2.1.210'
+	implementation 'org.springframework.boot:spring-boot-starter-validation'
 
 	implementation group: 'org.springdoc', name: 'springdoc-openapi-ui', version: '1.6.5'
-
+	implementation 'org.hibernate.validator:hibernate-validator'
 	testImplementation 'org.springframework.boot:spring-boot-starter-test'
 }
 

backend/lab/src/main/java/com/example/lab/DataBaseLab3/Models/Cart.java

@@ -1,7 +1,6 @@
 package com.example.lab.DataBaseLab3.Models;
 
 import jakarta.persistence.*;
-import jakarta.persistence.criteria.CriteriaBuilder;
 
 import java.util.*;
 
@@ -12,79 +11,37 @@ public class Cart {
     @GeneratedValue(strategy = GenerationType.AUTO)
     private Long id;
 
+    @OneToMany
+    private List<CountProduct> countProducts;
 
     @OneToOne
     private Customer customer;
-    @ManyToMany(fetch = FetchType.EAGER, mappedBy = "carts", cascade = CascadeType.ALL )
-    private List<Product> products; //can't count there because of "integer not @entity"
-    @ElementCollection(fetch = FetchType.EAGER)
-    @CollectionTable(name = "cart_products_count",
-            joinColumns = {@JoinColumn(name = "cart_id", referencedColumnName = "id")})
-    @MapKeyColumn(name = "product")
-    @Column(name = "amount")
-    private Map<Product, Integer>  countProducts; //count amount of products
 
     public Cart(){}
 
     public Cart(Customer customer) {
-        this.countProducts = new HashMap<>();
+        this.countProducts = new ArrayList<>();
         this.customer = customer;
     }
 
-    public List<Product> getProducts() {
-        return products;
-    }
-
-    public Map<Product,Integer> getCountProducts(){
-        return countProducts;
-    }
-
-    //изменяет ее значение если есть такой товар на +1
-    public void addProduct(Product product){
-        if(!countProducts.containsKey(product) || !products.contains(product)){
-            this.countProducts.put(product, 1);
-            this.products.add(product);
-        }
-        else{
-            countProducts.put(product, countProducts.get(product) + 1);
-        }
-        if (!product.getCarts().contains(this)){
-            product.addCart(this);
-        }
-    }
-
-    public void deleteProduct(Product product){
-            products.remove(product);
-            if (product.getCarts().contains(this)) {
-                product.removeCart(this);
-            }
-            countProducts.remove(product);
-    }
-
-    public void reduceProduct(Product product){
-        if (!countProducts.containsKey(product)) return;
-        if(countProducts.get(product)==1){
-            //delete the last one
-            deleteProduct(product);
-        }
-        else{
-            countProducts.put(product, countProducts.get(product) - 1);
-        }
-    }
     @PreRemove
     public void deleteThis(){
-        deleteAllProducts();
+        //deleteAllProducts();
         this.getCustomer().setCart(null);
     }
 
 
-    public void deleteAllProducts(){
+    public void addCountProduct(CountProduct countProduct){
-        ArrayList<Product> products = new ArrayList<>(this.products);
+        countProducts.add(countProduct);
-        this.countProducts.clear();
+        if (countProduct.getCart() != this) {
-        this.products.clear();
+            countProduct.setCart(this);
-        for (var product:
+        }
-                products) {
+    }
-            if (product.getCarts().contains(this)) product.removeCart(this);
+
+    public void deleteCountProduct(CountProduct countProduct){
+        countProducts.remove(countProduct);
+        if (countProduct.getCart() == this) {
+            countProduct.setCart(null);
         }
     }
 

backend/lab/src/main/java/com/example/lab/DataBaseLab3/Models/CountProduct.java

@@ -0,0 +1,87 @@
+package com.example.lab.DataBaseLab3.Models;
+import jakarta.persistence.*;
+
+import java.util.*;
+
+@Entity
+public class CountProduct {
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private Long id;
+
+    @Column
+    private Integer amount;
+
+    @ManyToOne(fetch = FetchType.EAGER)
+    @JoinColumn(name="cart_fk")
+    private Cart cart;
+
+    @ManyToOne(fetch = FetchType.EAGER)
+    @JoinColumn(name="product_fk")
+    private Product product;
+
+    public CountProduct(){}
+
+    public CountProduct(Cart cart, Product product) {
+        this.cart = cart;
+        this.product = product;
+        this.amount = 0;
+        this.cart.addCountProduct(this);
+        this.product.addCountProduct(this);
+    }
+
+    public void setProduct(Product product) {
+        this.product = product;
+        if (product != null && !product.getCountProducts().contains(this)){
+            product.addCountProduct(this);
+        }
+    }
+
+    public Cart getCart() {
+        return cart;
+    }
+
+    public void setCart(Cart cart) {
+        this.cart = cart;
+    }
+
+    public Product getProduct() {
+        return product;
+    }
+
+    public int getAmount() {
+        return amount;
+    }
+
+    public void setAmount(int amount) {
+        this.amount = amount;
+    }
+
+    public void incrementAmount(){
+        this.amount++;
+    }
+
+    public void decrementAmount(){
+        this.amount--;
+    }
+
+    @PreRemove
+    public void deleteThis(){
+        if(this.product !=null) this.product.deleteCountProduct(this);
+        if(this.cart !=null) this.cart.deleteCountProduct(this);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+        if (obj == null || getClass() != obj.getClass()) return false;
+        CountProduct countProducts = (CountProduct) obj;
+        return Objects.equals(id, countProducts.id);
+    }
+
+    @Override
+    public int hashCode(){
+        return Objects.hashCode(id);
+    }
+}
+

backend/lab/src/main/java/com/example/lab/DataBaseLab3/Models/Product.java

@@ -3,7 +3,6 @@ package com.example.lab.DataBaseLab3.Models;
 import jakarta.persistence.*;
 
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Objects;
 
@@ -15,12 +14,9 @@ public class Product {
     private String name;
     private float price;
 
+    @OneToMany
+    private List<CountProduct> countProducts;
 
-    @ManyToMany(fetch = FetchType.EAGER)
-    @JoinTable(name = "products_carts",
-            joinColumns = @JoinColumn(name = "product_fk"),
-            inverseJoinColumns = @JoinColumn(name = "cart_fk"))
-    private List<Cart> carts;
     @ManyToOne(fetch = FetchType.EAGER)
     @JoinColumn(name = "productCategory_fk")
     private ProductCategory productCategory;
@@ -31,6 +27,7 @@ public class Product {
         this.name = name;
         this.price = price;
         this.productCategory = productCategory;
+        this.countProducts = new ArrayList<>();
     }
 
     public ProductCategory getProductCategory() {
@@ -67,40 +64,31 @@ public class Product {
         return price;
     }
 
-
-    public void addCart(Cart cart) {
-        carts.add(cart);
-        if (!cart.getProducts().contains(this)) {
-            cart.addProduct(this);
-        }
-
-    }
     @PreRemove
     public void deleteThis(){
-        deleteAllCarts();
+        //deleteAllCarts();
         this.productCategory.getProducts().remove(this);
     }
 
-    public void deleteAllCarts(){
+
-        ArrayList<Cart> carts = new ArrayList<>(this.carts);
+    public List<CountProduct> getCountProducts(){
-        this.carts.clear();
+        return countProducts;
-        for (var cart:
+    }
-                carts) {
+
-            cart.deleteProduct(this);
+    public void addCountProduct(CountProduct countProduct){
+        countProducts.add(countProduct);
+        if (countProduct.getProduct() != this) {
+            countProduct.setProduct(this);
         }
     }
 
-    public void removeCart(Cart cart) {
+    public void deleteCountProduct(CountProduct countProduct){
-        carts.remove(cart);
+        countProducts.remove(countProduct);
-        if (cart.getProducts().contains(this)) {
+        if (countProduct.getProduct() == this) {
-            cart.deleteAllProducts();
+            countProduct.setProduct(null);
         }
     }
 
-    public List<Cart> getCarts() {
-        return carts;
-    }
-
     @Override
     public boolean equals(Object obj) {
         if (this == obj) return true;

backend/lab/src/main/java/com/example/lab/DataBaseLab3/Services/CartService.java

@@ -2,10 +2,10 @@ package com.example.lab.DataBaseLab3.Services;
 
 import com.example.lab.DataBaseLab3.Models.Customer;
 import com.example.lab.DataBaseLab3.Models.Product;
+import com.example.lab.DataBaseLab3.Models.CountProduct;
 import jakarta.persistence.*;
 import jakarta.transaction.Transactional;
 import org.springframework.stereotype.Service;
-import org.springframework.util.StringUtils;
 import com.example.lab.DataBaseLab3.Models.Cart;
 import java.util.List;
 
@@ -15,9 +15,11 @@ public class CartService {
     private EntityManager em;
 
     private final ProductService productService;
+    private final CountProductService countProductService;
 
-    public CartService(ProductService productService){
+    public CartService(ProductService productService, CountProductService countProductService){
         this.productService = productService;
+        this.countProductService = countProductService;
     }
 
     @Transactional
@@ -61,7 +63,9 @@ public class CartService {
     public Product addProduct(Long cartId, Long productId){
         Product product = productService.getProduct(productId);
         Cart cart = getCart(cartId);
-        cart.addProduct(product);
+        var countProduct = countProductService.getCountProduct(productId, cartId);
+        if(countProduct == null) countProduct = countProductService.addCountProduct(product, cart);
+        countProduct.incrementAmount();
         em.persist(cart);
         return product;
     }
@@ -70,7 +74,9 @@ public class CartService {
     public Product deleteProduct(Long cartId, Long productId){
         Product product = productService.getProduct(productId);
         Cart cart = getCart(cartId);
-        cart.deleteProduct(product);
+        var countProduct = countProductService.getCountProduct(productId, cartId);
+        if(countProduct == null) return null;
+        countProductService.deleteCountProduct(productId,cartId);
         em.persist(cart);
         return product;
     }
@@ -79,7 +85,10 @@ public class CartService {
     public Product reduceProduct(Long cartId, Long productId){
         Product product = productService.getProduct(productId);
         Cart cart = getCart(cartId);
-        cart.reduceProduct(product);
+        var countProduct = countProductService.getCountProduct(productId, cartId);
+        if(countProduct == null) return null;
+        countProduct.decrementAmount();
+        em.persist(countProduct);
         return product;
     }
 }

backend/lab/src/main/java/com/example/lab/DataBaseLab3/Services/CountProductService.java

@@ -0,0 +1,68 @@
+package com.example.lab.DataBaseLab3.Services;
+
+import com.example.lab.DataBaseLab3.Models.*;
+import jakarta.persistence.*;
+import jakarta.transaction.Transactional;
+import org.springframework.stereotype.Service;
+import com.example.lab.DataBaseLab3.Models.Product;
+
+import java.util.List;
+
+@Service
+public class CountProductService {
+    @PersistenceContext
+    private EntityManager em;
+
+    @Transactional
+    public CountProduct addCountProduct(Product product,
+                                         Cart cart){
+        CountProduct countProduct = new CountProduct(cart, product);
+        em.persist(countProduct);
+        return countProduct;
+    }
+
+    @Transactional
+    public CountProduct getCountProduct(long productId, long cartId){
+        var count = getAllCountProducts();
+        var countProduct = count.stream().filter(x -> x.getProduct().getId() == productId
+                && x.getCart().getId() == cartId ).findFirst();
+        if(countProduct.isEmpty()) return null;
+        else return countProduct.get();
+    }
+
+    @Transactional
+    public CountProduct incrementProduct (long productId, long cartId){
+        CountProduct countProduct = getCountProduct(productId, cartId);
+        countProduct.incrementAmount();
+        return em.merge(countProduct);
+    }
+
+    @Transactional
+    public CountProduct decrementProduct (long productId, long cartId){
+        CountProduct countProduct = getCountProduct(productId, cartId);
+        countProduct.decrementAmount();
+        return em.merge(countProduct);
+    }
+
+    @Transactional
+    public CountProduct deleteCountProduct(long productId, long cartId){
+        final CountProduct countProduct = getCountProduct(productId, cartId);
+        em.remove(countProduct);
+        return countProduct;
+    }
+
+    @Transactional
+    public void deleteAll(){
+        var list = getAllCountProducts();
+        for (var cp:
+             list) {
+            cp.deleteThis();
+            em.remove(cp);
+        }
+    }
+
+    @Transactional
+    public List<CountProduct> getAllCountProducts(){
+        return em.createQuery("from CountProduct", CountProduct.class).getResultList();
+    }
+}

backend/lab/src/test/java/com/example/lab/DBTests.java

@@ -1,13 +1,11 @@
 package com.example.lab;
 
-import com.example.lab.DataBaseLab3.Models.Cart;
+import com.example.lab.DataBaseLab3.Models.*;
-import com.example.lab.DataBaseLab3.Models.Customer;
-import com.example.lab.DataBaseLab3.Models.Product;
-import com.example.lab.DataBaseLab3.Models.ProductCategory;
 import com.example.lab.DataBaseLab3.Services.CartService;
 import com.example.lab.DataBaseLab3.Services.CustomerService;
 import com.example.lab.DataBaseLab3.Services.ProductCategoryService;
 import com.example.lab.DataBaseLab3.Services.ProductService;
+import com.example.lab.DataBaseLab3.Services.CountProductService;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -23,6 +21,9 @@ public class DBTests {
     ProductCategoryService productCategoryService;
     @Autowired
     ProductService productService;
+    @Autowired
+    CountProductService countProductService;
+
 
     @Test
     void testProductCategory(){
@@ -63,10 +64,8 @@ public class DBTests {
     @Test
     void testCustomer(){
         cleanAll();
-
         Customer customer = customerService.addCustomer("Ivan",
                 "Ivanov", "cityExample");
-        Cart cart = cartService.addCart(customer);
                 Assertions.assertEquals("Ivan", customerService
                 .getCustomer(customer.getId()).getFirstName());
         Assertions.assertEquals("Ivanov", customerService
@@ -101,7 +100,6 @@ public class DBTests {
         Cart cart = cartService.addCart(customer);
 
         Assertions.assertEquals(product,cartService.addProduct(cart.getId(), product.getId()));
-
         Assertions.assertEquals(cart,cartService.getCart(cart.getId()));
         Assertions.assertEquals(product, cartService.reduceProduct(cart.getId(),product.getId()));
         Assertions.assertEquals(product, cartService.deleteProduct(cart.getId(),product.getId()));
@@ -110,6 +108,7 @@ public class DBTests {
     }
 
     public void cleanAll(){
+        countProductService.deleteAll();
         productService.deleteAllProducts();
         cartService.deleteAllCarts();
         customerService.deleteAllCustomers();