Четвертая лабораторная работа. Созданы DTO, репозитории,ошибки, переделана часть сервисов.

backend/lab/src/main/java/com/example/lab/DataBase/DTOs/CartDTO.java

@@ -0,0 +1,19 @@
+package com.example.lab.DataBase.DTOs;
+import java.util.List;
+import com.example.lab.DataBase.Models.Cart;
+
+public class CartDTO {
+    public Long id;;
+
+    public CartDTO(Cart cart){
+        this.id = cart.getId();
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id){
+        this.id = id;
+    }
+}

backend/lab/src/main/java/com/example/lab/DataBase/DTOs/CountProductDTO.java

@@ -0,0 +1,30 @@
+package com.example.lab.DataBase.DTOs;
+import com.example.lab.DataBase.Models.CountProduct;
+
+import jakarta.persistence.Column;
+
+public class CountProductDTO {
+    private Long id;
+    public Integer amount;
+
+    public CountProductDTO(CountProduct countProduct){
+        this.id = countProduct.getId();
+        this.amount = countProduct.getAmount();
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id){
+        this.id = id;
+    }
+
+    public Integer getAmount() {
+        return amount;
+    }
+
+    public void setAmount(Integer amount){
+        this.amount = amount;
+    }
+}

backend/lab/src/main/java/com/example/lab/DataBase/DTOs/CustomerDTO.java

@@ -0,0 +1,49 @@
+package com.example.lab.DataBase.DTOs;
+import com.example.lab.DataBase.Models.Customer;
+import jakarta.persistence.Column;
+
+public class CustomerDTO {
+    public Long id;
+    public String firstName;
+    public String lastName;
+    public String customerAddress;
+
+    public CustomerDTO(Customer customer){
+        this.id = customer.getId();
+        this.lastName = customer.getLastName();
+        this.firstName = customer.getFirstName();
+        this.customerAddress = customer.getCustomerAddress();
+    }
+
+    public Long getId(){
+        return id;
+    }
+
+    public String getFirstName(){
+        return firstName;
+    }
+
+    public String getLastName(){
+        return lastName;
+    }
+
+    public String getCustomerAddress(){
+        return customerAddress;
+    }
+
+    public void setId(Long id){
+        this.id = id;
+    }
+
+    public void setFirstName(String firstName){
+        this.firstName = firstName;
+    }
+
+    public void setLastName(String lastName){
+        this.lastName = lastName;
+    }
+
+    public void setCustomerAddress(String customerAddress){
+        this.customerAddress = customerAddress;
+    }
+}

backend/lab/src/main/java/com/example/lab/DataBase/DTOs/ProductCategoryDTO.java

@@ -0,0 +1,29 @@
+package com.example.lab.DataBase.DTOs;
+import com.example.lab.DataBase.Models.Product;
+import com.example.lab.DataBase.Models.ProductCategory;
+
+public class ProductCategoryDTO {
+    public Long id;
+    public String name;
+
+    public ProductCategoryDTO(ProductCategory productCategory){
+        this.id = productCategory.getId();
+        this.name = productCategory.getName();
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id){
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name){
+        this.name = name;
+    }
+}

backend/lab/src/main/java/com/example/lab/DataBase/DTOs/ProductDTO.java

@@ -0,0 +1,38 @@
+package com.example.lab.DataBase.DTOs;
+import com.example.lab.DataBase.Models.Product;
+
+public class ProductDTO {
+    public Long id;
+    public String name;
+    public float price;
+
+    public ProductDTO(Product product){
+        this.id = product.getId();
+        this.name = product.getName();
+        this.price = product.getPrice();
+    }
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id){
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name){
+        this.name = name;
+    }
+
+    public float getPrice() {
+        return price;
+    }
+
+    public void setPrice(float price){
+        this.price = price;
+    }
+
+}

backend/lab/src/main/java/com/example/lab/DataBase/Exceptions/CartNotFoundException.java

@@ -0,0 +1,7 @@
+package com.example.lab.DataBase.Exceptions;
+
+public class CartNotFoundException extends RuntimeException{
+    public CartNotFoundException(Long id){
+        super(String.format("Cart with id: %s hasn't been found", id));
+    }
+}

backend/lab/src/main/java/com/example/lab/DataBase/Exceptions/CountProductNotFoundException.java

@@ -0,0 +1,7 @@
+package com.example.lab.DataBase.Exceptions;
+
+public class CountProductNotFoundException extends RuntimeException{
+    public CountProductNotFoundException(int count){
+        super(String.format("Product with count: %s hasn't been found", count));
+    }
+}

backend/lab/src/main/java/com/example/lab/DataBase/Exceptions/CustomerNotFoundException.java

@@ -0,0 +1,7 @@
+package com.example.lab.DataBase.Exceptions;
+
+public class CustomerNotFoundException extends RuntimeException{
+    public CustomerNotFoundException(Long id){
+        super(String.format("Customer with id: %s hasn't been found", id));
+    }
+}

backend/lab/src/main/java/com/example/lab/DataBase/Exceptions/ProductCategoryNotFoundException.java

@@ -0,0 +1,7 @@
+package com.example.lab.DataBase.Exceptions;
+
+public class ProductCategoryNotFoundException extends RuntimeException{
+    public ProductCategoryNotFoundException(Long id){
+        super(String.format("Product category with id: %s hasn't been found", id));
+    }
+}

backend/lab/src/main/java/com/example/lab/DataBase/Exceptions/ProductNotFoundException.java

@@ -0,0 +1,7 @@
+package com.example.lab.DataBase.Exceptions;
+
+public class ProductNotFoundException extends RuntimeException{
+    public ProductNotFoundException(Long id){
+        super(String.format("Product with id: %s hasn't been found", id));
+    }
+}

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

@@ -1,5 +1,6 @@
 package com.example.lab.DataBase.Models;
 import jakarta.persistence.*;
+import jakarta.validation.constraints.NotBlank;
 
 import java.util.*;
 
@@ -10,6 +11,7 @@ public class CountProduct {
     private Long id;
 
     @Column
+    @NotBlank(message = "Amount can't be empty, only 0")
     private Integer amount;
 
     @ManyToOne(fetch = FetchType.EAGER)
@@ -37,6 +39,14 @@ public class CountProduct {
         }
     }
 
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id){
+        this.id = id;
+    }
+
     public Cart getCart() {
         return cart;
     }

backend/lab/src/main/java/com/example/lab/DataBase/Models/Customer.java

@@ -1,6 +1,8 @@
 package com.example.lab.DataBase.Models;
 
 import jakarta.persistence.*;
+import jakarta.validation.constraints.NotBlank;
+
 import java.util.Objects;
 
 @Entity
@@ -9,10 +11,13 @@ public class Customer {
     @GeneratedValue(strategy = GenerationType.AUTO)
     private Long id;
     @Column
+    @NotBlank(message = "Customer's first name can't be empty")
     private String firstName;
     @Column
+    @NotBlank(message = "Customer's last name can't be empty")
     private String lastName;
     @Column
+    @NotBlank(message = "Customer's address can't be empty")
     private String customerAddress;
 
     @OneToOne(fetch = FetchType.EAGER, mappedBy = "customer", cascade = CascadeType.ALL)

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

@@ -1,6 +1,7 @@
 package com.example.lab.DataBase.Models;
 
 import jakarta.persistence.*;
+import jakarta.validation.constraints.NotBlank;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -11,7 +12,12 @@ public class Product {
     @Id
     @GeneratedValue(strategy = GenerationType.AUTO)
     private Long id;
+
+    @Column
+    @NotBlank(message = "Product's name can't be empty")
     private String name;
+    @Column
+    @NotBlank(message = "Price can't be empty")
     private float price;
 
     @OneToMany

backend/lab/src/main/java/com/example/lab/DataBase/Models/ProductCategory.java

@@ -1,6 +1,8 @@
 package com.example.lab.DataBase.Models;
 
 import jakarta.persistence.*;
+import jakarta.validation.constraints.NotBlank;
+
 import java.util.*;
 
 @Entity
@@ -8,6 +10,8 @@ public class ProductCategory {
     @Id
     @GeneratedValue(strategy = GenerationType.AUTO)
     private Long id;
+    @Column
+    @NotBlank(message = "Product category name can't be empty")
     private String name;
     @OneToMany(fetch = FetchType.EAGER, mappedBy = "productCategory", cascade = CascadeType.ALL)
     private List<Product> products;

backend/lab/src/main/java/com/example/lab/DataBase/Repositories/CartRepository.java

@@ -0,0 +1,7 @@
+package com.example.lab.DataBase.Repositories;
+
+import com.example.lab.DataBase.Models.Cart;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface CartRepository extends JpaRepository<Cart, Long> {
+}

backend/lab/src/main/java/com/example/lab/DataBase/Repositories/CountProductRepository.java

@@ -0,0 +1,7 @@
+package com.example.lab.DataBase.Repositories;
+
+import com.example.lab.DataBase.Models.CountProduct;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface CountProductRepository extends JpaRepository<CountProduct, Integer> {
+}

backend/lab/src/main/java/com/example/lab/DataBase/Repositories/CustomerRepository.java

@@ -0,0 +1,7 @@
+package com.example.lab.DataBase.Repositories;
+
+import com.example.lab.DataBase.Models.Customer;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface CustomerRepository extends JpaRepository<Customer, Long> {
+}

backend/lab/src/main/java/com/example/lab/DataBase/Repositories/ProductCategoryRepository.java

@@ -0,0 +1,7 @@
+package com.example.lab.DataBase.Repositories;
+
+import com.example.lab.DataBase.Models.ProductCategory;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface ProductCategoryRepository extends JpaRepository<ProductCategory, Long> {
+}

backend/lab/src/main/java/com/example/lab/DataBase/Repositories/ProductRepository.java

@@ -0,0 +1,7 @@
+package com.example.lab.DataBase.Repositories;
+
+import com.example.lab.DataBase.Models.Product;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface ProductRepository extends JpaRepository<Product, Long> {
+}

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

@@ -1,61 +1,61 @@
 package com.example.lab.DataBase.Services;
 
+import com.example.lab.DataBase.Exceptions.CustomerNotFoundException;
 import com.example.lab.DataBase.Models.Customer;
 import com.example.lab.DataBase.Models.Product;
+import com.example.lab.DataBase.Repositories.CustomerRepository;
 import jakarta.persistence.*;
 import jakarta.transaction.Transactional;
 import org.springframework.stereotype.Service;
 import com.example.lab.DataBase.Models.Cart;
+import com.example.lab.DataBase.Repositories.CartRepository;
+import com.example.lab.DataBase.Exceptions.CartNotFoundException;
+import com.example.lab.DataBase.util.Validation.ValidatorUtil;
+import com.example.lab.DataBase.util.Validation.ValidationException;
 import java.util.List;
 
 @Service
 public class CartService {
-    @PersistenceContext
-    private EntityManager em;
 
     private final ProductService productService;
     private final CountProductService countProductService;
+    private final CartRepository cartRepository;
+    private final ValidatorUtil validatorUtil;
 
-    public CartService(ProductService productService, CountProductService countProductService){
+    public CartService(ProductService productService, CountProductService countProductService,
+                       CartRepository cartRepository, ValidatorUtil validatorUtil){
         this.productService = productService;
         this.countProductService = countProductService;
+        this.cartRepository = cartRepository;
+        this.validatorUtil = validatorUtil;
     }
 
     @Transactional
     public Cart addCart(Customer customer){
         Cart cart = new Cart(customer);
-        cart.getCustomer().setCart(cart);
-        em.persist(cart);
-        return cart;
+        validatorUtil.validate(cart);
+        return cartRepository.save(cart);
     }
 
     @Transactional()
     public Cart getCart(Long id){
-        Cart cart = em.find(Cart.class, id);
-        if (cart == null){
-            throw new EntityNotFoundException(String.format("Error: Cart id %s not found", id));
-        }
-        return cart;
+        return cartRepository.findById(id).orElseThrow(() -> new CartNotFoundException(id));
     }
 
     @Transactional
     public List<Cart> getAllCarts(){
-        return em.createQuery("from Cart", Cart.class).getResultList();
+        return cartRepository.findAll();
     }
 
     @Transactional
     public Cart deleteCart(Long id){
-        final Cart cart = getCart(id);
-        em.remove(cart);
+        Cart cart = getCart(id);
+        cartRepository.delete(cart);
         return cart;
     }
     @Transactional
     public void deleteAllCarts(){
-        for (var cart:
-             getAllCarts()) {
-            cart.deleteThis();
-            em.remove(cart);
-        }
+        cartRepository.deleteAll();
     }
 
     @Transactional

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

@@ -1,7 +1,9 @@
 package com.example.lab.DataBase.Services;
 
+import com.example.lab.DataBase.Exceptions.CustomerNotFoundException;
 import com.example.lab.DataBase.Models.*;
-import jakarta.persistence.*;
+import com.example.lab.DataBase.Repositories.CountProductRepository;
+import com.example.lab.DataBase.util.Validation.ValidatorUtil;
 import jakarta.transaction.Transactional;
 import org.springframework.stereotype.Service;
 import com.example.lab.DataBase.Models.Product;
@@ -10,24 +12,26 @@ import java.util.List;
 
 @Service
 public class CountProductService {
-    @PersistenceContext
-    private EntityManager em;
+    private final CountProductRepository countProductRepository;
+    private final ValidatorUtil validatorUtil;
+
+    public CountProductService(CountProductRepository countProductRepository,
+                           ValidatorUtil validatorUtil){
+        this.countProductRepository= countProductRepository;
+        this.validatorUtil = validatorUtil;
+    }
 
     @Transactional
     public CountProduct addCountProduct(Product product,
                                          Cart cart){
         CountProduct countProduct = new CountProduct(cart, product);
-        em.persist(countProduct);
-        return countProduct;
+        validatorUtil.validate(countProduct);
+        return countProductRepository.save(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();
+        return countProductRepository.findById(productId, cartId).orElseThrow(() -> new CustomerNotFoundException(id));
     }
 
     @Transactional
@@ -46,23 +50,18 @@ public class CountProductService {
 
     @Transactional
     public CountProduct deleteCountProduct(long productId, long cartId){
-        final CountProduct countProduct = getCountProduct(productId, cartId);
-        em.remove(countProduct);
+        CountProduct countProduct = getCountProduct(productId,cartId);
+        countProductRepository.delete(countProduct);
         return countProduct;
     }
 
     @Transactional
     public void deleteAll(){
-        var list = getAllCountProducts();
-        for (var cp:
-             list) {
-            cp.deleteThis();
-            em.remove(cp);
-        }
+        countProductRepository.deleteAll();
     }
 
     @Transactional
     public List<CountProduct> getAllCountProducts(){
-        return em.createQuery("from CountProduct", CountProduct.class).getResultList();
+        return countProductRepository.findAll();
     }
 }

backend/lab/src/main/java/com/example/lab/DataBase/Services/CustomerService.java

@@ -1,66 +1,61 @@
 package com.example.lab.DataBase.Services;
-import jakarta.persistence.*;
+import com.example.lab.DataBase.Exceptions.CustomerNotFoundException;
 import jakarta.transaction.Transactional;
 import org.springframework.stereotype.Service;
 import org.springframework.util.StringUtils;
 import com.example.lab.DataBase.Models.Customer;
+import com.example.lab.DataBase.Repositories.CustomerRepository;
+import com.example.lab.DataBase.Exceptions.CustomerNotFoundException;
+import com.example.lab.DataBase.util.Validation.ValidatorUtil;
+import com.example.lab.DataBase.util.Validation.ValidationException;
 import java.util.List;
 
 @Service
 public class CustomerService {
-    @PersistenceContext
-    private EntityManager em;
+    private final CustomerRepository customerRepository;
+    private final ValidatorUtil validatorUtil;
+
+    public CustomerService(CustomerRepository customerRepository,
+                           ValidatorUtil validatorUtil){
+        this.customerRepository = customerRepository;
+        this.validatorUtil = validatorUtil;
+    }
 
     @Transactional
     public Customer addCustomer(String customerFirstName, String customerLastName, String customerAddress){
-        if (!StringUtils.hasText(customerFirstName) || !StringUtils.hasText(customerLastName)){
-            throw new IllegalArgumentException("Customer first and last names can't be null");
-        }
-        else if(!StringUtils.hasText(customerAddress)){
-            throw new IllegalArgumentException("Customer address can't be null");
-        }
         Customer customer = new Customer(customerLastName, customerFirstName, customerAddress);
-        em.persist(customer);
-        return customer;
+        validatorUtil.validate(customer);
+        return customerRepository.save(customer);
     }
 
     @Transactional()
     public Customer getCustomer(Long id){
-        Customer customer = em.find(Customer.class, id);
-        if (customer == null){
-            throw new EntityNotFoundException(String.format("Error: Customer id %s not found", id));
-        }
-        return customer;
+        return customerRepository.findById(id).orElseThrow(() -> new CustomerNotFoundException(id));
     }
 
     @Transactional
     public List<Customer> getAllCustomers(){
-        return em.createQuery("get c from Customer c", Customer.class).getResultList();
+        return customerRepository.findAll();
     }
 
     @Transactional
     public Customer updateCustomer(Long id, String customerLastName, String customerFirstName, String customerAddress){
-        if (!StringUtils.hasText(customerLastName) || !StringUtils.hasText(customerFirstName)){
-            throw new IllegalArgumentException("Customer last or/and first name is null");
-        }
-        if (!StringUtils.hasText(customerAddress)){
-            throw new IllegalArgumentException("Customer address can't be null");
-        }
         final Customer customer = getCustomer(id);
         customer.setLastName(customerLastName);
         customer.setFirstName(customerFirstName);
         customer.setCustomerAddress(customerAddress);
-        return em.merge(customer);
+        validatorUtil.validate(customer);
+        return customerRepository.save(customer);
     }
 
     @Transactional
     public Customer deleteCustomer(Long id){
-        final Customer customer = getCustomer(id);
-        em.remove(customer);
+        Customer customer = getCustomer(id);
+        customerRepository.delete(customer);
         return customer;
     }
     @Transactional
     public void deleteAllCustomers(){
-        em.createQuery("Delete from Customer").executeUpdate();
+        customerRepository.deleteAll();
     }
 }

backend/lab/src/main/java/com/example/lab/DataBase/Services/ProductCategoryService.java

@@ -1,6 +1,8 @@
 package com.example.lab.DataBase.Services;
 
-import jakarta.persistence.*;
+import com.example.lab.DataBase.Exceptions.ProductCategoryNotFoundException;
+import com.example.lab.DataBase.Repositories.ProductCategoryRepository;
+import com.example.lab.DataBase.util.Validation.ValidatorUtil;
 import jakarta.transaction.Transactional;
 import org.springframework.stereotype.Service;
 import org.springframework.util.StringUtils;
@@ -9,51 +11,48 @@ import java.util.List;
 
 @Service
 public class ProductCategoryService {
-    @PersistenceContext
-    private EntityManager em;
+    private final ProductCategoryRepository productCategoryRepository;
+    private final ValidatorUtil validatorUtil;
+
+    public ProductCategoryService(ProductCategoryRepository productCategoryRepository,
+                       ValidatorUtil validatorUtil){
+        this.productCategoryRepository = productCategoryRepository;
+        this.validatorUtil = validatorUtil;
+    }
 
     @Transactional
     public ProductCategory addProductCategory(String name){
-        if (!StringUtils.hasText(name)){
-            throw new IllegalArgumentException("ProductCategory name can't be null");
-        }
         ProductCategory productCategory = new ProductCategory(name);
-        em.persist(productCategory);
-        return productCategory;
+        validatorUtil.validate(productCategory);
+        return productCategoryRepository.save(productCategory);
     }
 
     @Transactional()
     public ProductCategory getProductCategory(Long id){
-        ProductCategory productCategory = em.find(ProductCategory.class, id);
-        if (productCategory == null){
-            throw new EntityNotFoundException(String.format("Error: ProductCategory id %s not found", id));
-        }
-        return productCategory;
+        return productCategoryRepository.findById(id).orElseThrow(() -> new ProductCategoryNotFoundException(id));
     }
 
     @Transactional
     public List<ProductCategory> getAllProductCategorys(){
-        return em.createQuery("get c from ProductCategory c", ProductCategory.class).getResultList();
+        return productCategoryRepository.findAll();
     }
 
     @Transactional
     public ProductCategory updateProductCategory(Long id, String productCategoryName){
-        if (!StringUtils.hasText(productCategoryName)){
-            throw new IllegalArgumentException("ProductCategory name is null");
-        }
         final ProductCategory productCategory = getProductCategory(id);
         productCategory.setName(productCategoryName);
-        return em.merge(productCategory);
+        validatorUtil.validate(productCategory);
+        return productCategoryRepository.save(productCategory);
     }
 
     @Transactional
     public ProductCategory deleteProductCategory(Long id){
         final ProductCategory productCategory = getProductCategory(id);
-        em.remove(productCategory);
+        productCategoryRepository.delete(productCategory);
         return productCategory;
     }
     @Transactional
     public void deleteAllProductCategories(){
-        em.createQuery("Delete from ProductCategory").executeUpdate();
+        productCategoryRepository.deleteAll();
     }
 }

backend/lab/src/main/java/com/example/lab/DataBase/Services/ProductService.java

@@ -1,7 +1,9 @@
 package com.example.lab.DataBase.Services;
 
+import com.example.lab.DataBase.Exceptions.ProductNotFoundException;
 import com.example.lab.DataBase.Models.ProductCategory;
-import jakarta.persistence.*;
+import com.example.lab.DataBase.Repositories.ProductRepository;
+import com.example.lab.DataBase.util.Validation.ValidatorUtil;
 import jakarta.transaction.Transactional;
 import org.springframework.stereotype.Service;
 import org.springframework.util.StringUtils;
@@ -10,30 +12,26 @@ import java.util.List;
 
 @Service
 public class ProductService {
-    @PersistenceContext
-    private EntityManager em;
+
+    private final ProductRepository productRepository;
+    private final ValidatorUtil validatorUtil;
+
+    public ProductService(ProductRepository productRepository,
+                                  ValidatorUtil validatorUtil){
+        this.productRepository = productRepository;
+        this.validatorUtil = validatorUtil;
+    }
 
     @Transactional
     public Product addProduct(String name, float price, ProductCategory productCategory){
-        if (!StringUtils.hasText(name)){
-            throw new IllegalArgumentException("Product first and last names can't be null");
-        }
-        else if(price <= 0){
-            throw new IllegalArgumentException("Product price cant be under 0");
-        }
         Product product = new Product(name, price, productCategory);
-        product.getProductCategory().AddProduct(product);
-        em.persist(product);
-        return product;
+        validatorUtil.validate(product);
+        return productRepository.save(product);
     }
 
     @Transactional()
     public Product getProduct(Long id){
-        Product product = em.find(Product.class, id);
-        if (product == null){
-            throw new EntityNotFoundException(String.format("Error: Product id %s not found", id));
-        }
-        return product;
+        return productRepository.findById(id).orElseThrow(() -> new ProductNotFoundException(id));
     }
 
     @Transactional

backend/lab/src/main/java/com/example/lab/DataBase/util/Error/AdviceController.java

@@ -0,0 +1,44 @@
+package com.example.lab.DataBase.util.Error;
+
+import java.util.stream.Collectors;
+import com.example.lab.DataBase.Exceptions.CountProductNotFoundException;
+import com.example.lab.DataBase.Exceptions.ProductCategoryNotFoundException;
+import com.example.lab.DataBase.Exceptions.CustomerNotFoundException;
+import com.example.lab.DataBase.Exceptions.ProductNotFoundException;
+import com.example.lab.DataBase.Exceptions.CartNotFoundException;
+import com.example.lab.DataBase.util.Validation.ValidationException;
+import org.springframework.context.support.DefaultMessageSourceResolvable;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+
+
+@ControllerAdvice
+public class AdviceController {
+    @ExceptionHandler({
+            CustomerNotFoundException.class,
+            ProductCategoryNotFoundException.class,
+            ProductNotFoundException.class,
+            CountProductNotFoundException.class,
+            CartNotFoundException.class,
+    })
+    public ResponseEntity<Object> handleException(Throwable e){
+        return new ResponseEntity<>(e.getMessage(), HttpStatus.BAD_REQUEST);
+    }
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ResponseEntity<Object> handleBindException(MethodArgumentNotValidException e) {
+        final ValidationException validationException = new ValidationException(
+                e.getBindingResult().getAllErrors().stream()
+                        .map(DefaultMessageSourceResolvable::getDefaultMessage)
+                        .collect(Collectors.toSet()));
+        return handleException(validationException);
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<Object> handleUnknownException(Throwable e) {
+        e.printStackTrace();
+        return new ResponseEntity<>(e.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);
+    }
+}

backend/lab/src/main/java/com/example/lab/DataBase/util/Validation/ValidationException.java

@@ -0,0 +1,9 @@
+package com.example.lab.DataBase.util.Validation;
+
+import java.util.Set;
+
+public class ValidationException extends RuntimeException{
+    public ValidationException(Set<String> errors){
+        super(String.join("\n", errors));
+    }
+}

backend/lab/src/main/java/com/example/lab/DataBase/util/Validation/ValidatorUtil.java

@@ -0,0 +1,30 @@
+package com.example.lab.DataBase.util.Validation;
+
+import jakarta.validation.ConstraintViolation;
+import jakarta.validation.Validation;
+import jakarta.validation.Validator;
+import jakarta.validation.ValidatorFactory;
+import org.springframework.stereotype.Component;
+
+import java.util.Set;
+import java.util.stream.Collectors;
+
+@Component
+public class ValidatorUtil {
+    private final Validator validator;
+
+    public ValidatorUtil(){
+        try (ValidatorFactory factory = Validation.buildDefaultValidatorFactory()){
+            this.validator = factory.getValidator();
+        }
+    }
+
+    public <T> void validate(T object) {
+        final Set<ConstraintViolation<T>> errors = validator.validate(object);
+        if (!errors.isEmpty()) {
+            throw new ValidationException(errors.stream()
+                    .map(ConstraintViolation::getMessage)
+                    .collect(Collectors.toSet()));
+        }
+    }
+}