Простая реализация электронной коммерции с помощью Spring

    org.springframework.boot
    spring-boot-starter-data-jpa
    2.2.2.RELEASE


    org.springframework.boot
    spring-boot-starter-web
    2.2.2.RELEASE

    com.h2database
    h2
    1.4.197
    runtime

    com.fasterxml.jackson.datatype
    jackson-datatype-jsr310
    2.9.6

spring.datasource.name=ecommercedb
spring.jpa.show-sql=true

#H2 settings
spring.h2.console.enabled=true
spring.h2.console.path=/h2-console

├───pom.xml            
├───src
    ├───main
    │   ├───frontend
    │   ├───java
    │   │   └───com
    │   │       └───baeldung
    │   │           └───ecommerce
    │   │               │   EcommerceApplication.java
    │   │               ├───controller 
    │   │               ├───dto  
    │   │               ├───exception
    │   │               ├───model
    │   │               ├───repository
    │   │               └───service
    │   │                       
    │   └───resources
    │       │   application.properties
    │       ├───static
    │       └───templates
    └───test
        └───java
            └───com
                └───baeldung
                    └───ecommerce
                            EcommerceApplicationIntegrationTest.java

@RestControllerAdvice
public class ApiExceptionHandler {

    @SuppressWarnings("rawtypes")
    @ExceptionHandler(ConstraintViolationException.class)
    public ResponseEntity handle(ConstraintViolationException e) {
        ErrorResponse errors = new ErrorResponse();
        for (ConstraintViolation violation : e.getConstraintViolations()) {
            ErrorItem error = new ErrorItem();
            error.setCode(violation.getMessageTemplate());
            error.setMessage(violation.getMessage());
            errors.addError(error);
        }
        return new ResponseEntity<>(errors, HttpStatus.BAD_REQUEST);
    }

    @SuppressWarnings("rawtypes")
    @ExceptionHandler(ResourceNotFoundException.class)
    public ResponseEntity handle(ResourceNotFoundException e) {
        ErrorItem error = new ErrorItem();
        error.setMessage(e.getMessage());

        return new ResponseEntity<>(error, HttpStatus.NOT_FOUND);
    }
}

@Entity
public class Product {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @NotNull(message = "Product name is required.")
    @Basic(optional = false)
    private String name;

    private Double price;

    private String pictureUrl;

    // all arguments contructor 
    // standard getters and setters
}

@Service
@Transactional
public class ProductServiceImpl implements ProductService {

    // productRepository constructor injection

    @Override
    public Iterable getAllProducts() {
        return productRepository.findAll();
    }

    @Override
    public Product getProduct(long id) {
        return productRepository
          .findById(id)
          .orElseThrow(() -> new ResourceNotFoundException("Product not found"));
    }

    @Override
    public Product save(Product product) {
        return productRepository.save(product);
    }
}

@RestController
@RequestMapping("/api/products")
public class ProductController {

    // productService constructor injection

    @GetMapping(value = { "", "/" })
    public @NotNull Iterable getProducts() {
        return productService.getAllProducts();
    }
}

@Bean
CommandLineRunner runner(ProductService productService) {
    return args -> {
        productService.save(...);
        // more products
}

@Entity
@Table(name = "orders")
public class Order {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @JsonFormat(pattern = "dd/MM/yyyy")
    private LocalDate dateCreated;

    private String status;

    @JsonManagedReference
    @OneToMany(mappedBy = "pk.order")
    @Valid
    private List orderProducts = new ArrayList<>();

    @Transient
    public Double getTotalOrderPrice() {
        double sum = 0D;
        List orderProducts = getOrderProducts();
        for (OrderProduct op : orderProducts) {
            sum += op.getTotalPrice();
        }
        return sum;
    }

    @Transient
    public int getNumberOfProducts() {
        return this.orderProducts.size();
    }

    // standard getters and setters
}

@Entity
public class OrderProduct {

    @EmbeddedId
    @JsonIgnore
    private OrderProductPK pk;

    @Column(nullable = false)
	private Integer quantity;

    // default constructor

    public OrderProduct(Order order, Product product, Integer quantity) {
        pk = new OrderProductPK();
        pk.setOrder(order);
        pk.setProduct(product);
        this.quantity = quantity;
    }

    @Transient
    public Product getProduct() {
        return this.pk.getProduct();
    }

    @Transient
    public Double getTotalPrice() {
        return getProduct().getPrice() * getQuantity();
    }

    // standard getters and setters

    // hashcode() and equals() methods
}

@Embeddable
public class OrderProductPK implements Serializable {

    @JsonBackReference
    @ManyToOne(optional = false, fetch = FetchType.LAZY)
    @JoinColumn(name = "order_id")
    private Order order;

    @ManyToOne(optional = false, fetch = FetchType.LAZY)
    @JoinColumn(name = "product_id")
    private Product product;

    // standard getters and setters

    // hashcode() and equals() methods
}

@Service
@Transactional
public class OrderServiceImpl implements OrderService {

    // orderRepository constructor injection

    @Override
    public Iterable getAllOrders() {
        return this.orderRepository.findAll();
    }
	
    @Override
    public Order create(Order order) {
        order.setDateCreated(LocalDate.now());
        return this.orderRepository.save(order);
    }

    @Override
    public void update(Order order) {
        this.orderRepository.save(order);
    }
}

@PostMapping
public ResponseEntity create(@RequestBody OrderForm form) {
    List formDtos = form.getProductOrders();
    validateProductsExistence(formDtos);
    // create order logic
    // populate order with products

    order.setOrderProducts(orderProducts);
    this.orderService.update(order);

    String uri = ServletUriComponentsBuilder
      .fromCurrentServletMapping()
      .path("/orders/{id}")
      .buildAndExpand(order.getId())
      .toString();
    HttpHeaders headers = new HttpHeaders();
    headers.add("Location", uri);

    return new ResponseEntity<>(order, headers, HttpStatus.CREATED);
}

ng new frontend

npm install --save bootstrap

ng g c ecommerce

ng g c /ecommerce/products
ng g c /ecommerce/orders
ng g c /ecommerce/shopping-cart

export class Product {
    id: number;
    name: string;
    price: number;
    pictureUrl: string;

    // all arguments constructor
}

export class ProductOrder {
    product: Product;
    quantity: number;

    // all arguments constructor
}

export class ProductOrders {
    productOrders: ProductOrder[] = [];
}

.container {
    padding-top: 65px;
}

@Component({
    selector: 'app-ecommerce',
    templateUrl: './ecommerce.component.html',
    styleUrls: ['./ecommerce.component.css']
})
export class EcommerceComponent implements OnInit {
    private collapsed = true;
    orderFinished = false;

    @ViewChild('productsC')
    productsC: ProductsComponent;

    @ViewChild('shoppingCartC')
    shoppingCartC: ShoppingCartComponent;

    @ViewChild('ordersC')
    ordersC: OrdersComponent;

    toggleCollapsed(): void {
        this.collapsed = !this.collapsed;
    }

    finishOrder(orderFinished: boolean) {
        this.orderFinished = orderFinished;
    }

    reset() {
        this.orderFinished = false;
        this.productsC.reset();
        this.shoppingCartC.reset();
        this.ordersC.paid = false;
    }
}

@Injectable()
export class EcommerceService {
    private productsUrl = "/api/products";
    private ordersUrl = "/api/orders";

    private productOrder: ProductOrder;
    private orders: ProductOrders = new ProductOrders();

    private productOrderSubject = new Subject();
    private ordersSubject = new Subject();
    private totalSubject = new Subject();

    private total: number;

    ProductOrderChanged = this.productOrderSubject.asObservable();
    OrdersChanged = this.ordersSubject.asObservable();
    TotalChanged = this.totalSubject.asObservable();

    constructor(private http: HttpClient) {
    }

    getAllProducts() {
        return this.http.get(this.productsUrl);
    }

    saveOrder(order: ProductOrders) {
        return this.http.post(this.ordersUrl, order);
    }

    // getters and setters for shared fields
}

{
    "/api": {
        "target": "http://localhost:8080",
        "secure": false
    }
}

"scripts": {
    ...
    "start": "ng serve --proxy-config proxy-conf.json",
    ...
  }

export class ProductsComponent implements OnInit {
    productOrders: ProductOrder[] = [];
    products: Product[] = [];
    selectedProductOrder: ProductOrder;
    private shoppingCartOrders: ProductOrders;
    sub: Subscription;
    productSelected: boolean = false;

    constructor(private ecommerceService: EcommerceService) {}

    ngOnInit() {
        this.productOrders = [];
        this.loadProducts();
        this.loadOrders();
    }

    loadProducts() {
        this.ecommerceService.getAllProducts()
            .subscribe(
                (products: any[]) => {
                    this.products = products;
                    this.products.forEach(product => {
                        this.productOrders.push(new ProductOrder(product, 0));
                    })
                },
                (error) => console.log(error)
            );
    }

    loadOrders() {
        this.sub = this.ecommerceService.OrdersChanged.subscribe(() => {
            this.shoppingCartOrders = this.ecommerceService.ProductOrders;
        });
    }
}

addToCart(order: ProductOrder) {
    this.ecommerceService.SelectedProductOrder = order;
    this.selectedProductOrder = this.ecommerceService.SelectedProductOrder;
    this.productSelected = true;
}

removeFromCart(productOrder: ProductOrder) {
    let index = this.getProductIndex(productOrder.product);
    if (index > -1) {
        this.shoppingCartOrders.productOrders.splice(
            this.getProductIndex(productOrder.product), 1);
    }
    this.ecommerceService.ProductOrders = this.shoppingCartOrders;
    this.shoppingCartOrders = this.ecommerceService.ProductOrders;
    this.productSelected = false;
}

reset() {
    this.productOrders = [];
    this.loadProducts();
    this.ecommerceService.ProductOrders.productOrders = [];
    this.loadOrders();
    this.productSelected = false;
}

    

        

            

                
{{order.product.name}}
            
            

                
                
${{order.product.price}}
                

                    

                        
                    
                    

                        Add To Cart
                        
                    
                    

                        Remove From Cart
                        
                    
                
            
        
    

.padding-0 {
    padding-right: 0;
    padding-left: 1;
}

export class ShoppingCartComponent implements OnInit, OnDestroy {
    orderFinished: boolean;
    orders: ProductOrders;
    total: number;
    sub: Subscription;

    @Output() onOrderFinished: EventEmitter;

    constructor(private ecommerceService: EcommerceService) {
        this.total = 0;
        this.orderFinished = false;
        this.onOrderFinished = new EventEmitter();
    }

    ngOnInit() {
        this.orders = new ProductOrders();
        this.loadCart();
        this.loadTotal();
    }

    loadTotal() {
        this.sub = this.ecommerceService.OrdersChanged.subscribe(() => {
            this.total = this.calculateTotal(this.orders.productOrders);
        });
    }

    loadCart() {
        this.sub = this.ecommerceService.ProductOrderChanged.subscribe(() => {
            let productOrder = this.ecommerceService.SelectedProductOrder;
            if (productOrder) {
                this.orders.productOrders.push(new ProductOrder(
                    productOrder.product, productOrder.quantity));
            }
            this.ecommerceService.ProductOrders = this.orders;
            this.orders = this.ecommerceService.ProductOrders;
            this.total = this.calculateTotal(this.orders.productOrders);
        });
    }

    ngOnDestroy() {
        this.sub.unsubscribe();
    }
}

finishOrder() {
    this.orderFinished = true;
    this.ecommerceService.Total = this.total;
    this.onOrderFinished.emit(this.orderFinished);
}

reset() {
    this.orderFinished = false;
    this.orders = new ProductOrders();
    this.orders.productOrders = []
    this.loadTotal();
    this.total = 0;
}

    
Shopping Cart
    

        
Total: ${{total}}
        

        
Items bought:

        

            

                {{ order.product.name }} - {{ order.quantity}} pcs.
            
        

        Checkout
        
    

export class OrdersComponent implements OnInit {
    orders: ProductOrders;
    total: number;
    paid: boolean;
    sub: Subscription;

    constructor(private ecommerceService: EcommerceService) {
        this.orders = this.ecommerceService.ProductOrders;
    }

    ngOnInit() {
        this.paid = false;
        this.sub = this.ecommerceService.OrdersChanged.subscribe(() => {
            this.orders = this.ecommerceService.ProductOrders;
        });
        this.loadTotal();
    }

    pay() {
        this.paid = true;
        this.ecommerceService.saveOrder(this.orders).subscribe();
    }
}

ORDER

    

        {{ order.product.name }} - ${{ order.product.price }} x {{ order.quantity}} pcs.
    

Total amount: ${{ total }}

Pay

    Congratulation! You successfully made the order.

"postbuild": "npm run deploy",
"predeploy": "rimraf ../resources/static/ && mkdirp ../resources/static",
"deploy": "copyfiles -f dist/** ../resources/static",

npm install --save-dev rimraf
npm install --save-dev mkdirp
npm install --save-dev copyfiles