Koszyk

PC30-SklepSpring/src/main/java/sklep/basket/Basket.java

+package sklep.basket;
+
+import java.math.BigDecimal;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import sklep.model.Product;
+
+public class Basket {
+	private final Map<Integer, ProductInBasket> elementy = new HashMap<>();
+	
+	public synchronized void addProduct(Product product, int quantity) {
+		if(elementy.containsKey(product.getProductId())) {
+			// jeśli w słowniku jest już taki element, to tylko zwiększamy ilość
+			elementy.get(product.getProductId()).increaseQuantity(quantity);
+		} else {
+			// jeśli jeszcze nie ma, to tworzymy
+			elementy.put(product.getProductId(),
+					new ProductInBasket(product.getProductId(), product.getProductName(), product.getPrice(), quantity));
+		}
+	}
+
+	public synchronized void addProduct(Product product) {
+		// "domyślną ilością, o którą zwiększamy, jest 1"
+		addProduct(product, 1);
+	}
+
+	
+	public synchronized Collection<ProductInBasket> getElements() {
+		return Collections.unmodifiableCollection(elementy.values());
+	}
+
+	public synchronized BigDecimal getTotalValue() {
+		return getElements().stream()
+				.map(ProductInBasket::getValue)
+				.reduce(BigDecimal.ZERO, BigDecimal::add);
+	}
+	
+	@Override
+	public synchronized String toString() {
+		return "Koszyk o rozmiarze " + getElements().size()
+				+ " i wartości " + getTotalValue();
+	}
+	
+}

PC30-SklepSpring/src/main/java/sklep/basket/BasketConfiguration.java

+package sklep.basket;
+
+import javax.servlet.http.HttpSession;
+import javax.servlet.http.HttpSessionEvent;
+import javax.servlet.http.HttpSessionListener;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class BasketConfiguration {
+
+	// Spring utworzy obiekt klasy BasketConfiguration i wykona metodę listenerSesji.
+	// Uzyskany w ten sposób obiekt HttpSessionListener zostanie zarejestrowany jako listener sesji,
+	// a zatem metoda sessionCreated będzie wykonywana za każdym razem, gdy w aplikacji będzie powstawać nowa sesja
+	// (gdy nowy klient wejdzie na stronę).
+	@Bean
+	public HttpSessionListener listenerSesji() {
+		return new HttpSessionListener() {
+			@Override
+			public void sessionCreated(HttpSessionEvent se) {
+				HttpSession session = se.getSession();
+				session.setAttribute("basket", new Basket());
+			}
+			
+			@Override
+			public void sessionDestroyed(HttpSessionEvent se) {
+			}
+		};
+	}
+	
+}

PC30-SklepSpring/src/main/java/sklep/basket/ProductInBasket.java

+package sklep.basket;
+
+import java.math.BigDecimal;
+import java.util.Objects;
+
+public class ProductInBasket {
+    private int productId;
+    private String productName;
+    private BigDecimal price;
+    private int quantity;
+    
+	public ProductInBasket(int productId, String productName, BigDecimal price, int quantity) {
+		this.productId = productId;
+		this.productName = productName;
+		this.price = price;
+		this.quantity = quantity;
+	}
+
+	public BigDecimal getPrice() {
+		return price;
+	}
+
+	public void setPrice(BigDecimal price) {
+		this.price = price;
+	}
+
+	public int getQuantity() {
+		return quantity;
+	}
+
+	public void setQuantity(int quantity) {
+		this.quantity = quantity;
+	}
+
+	public int getProductId() {
+		return productId;
+	}
+
+	public String getProductName() {
+		return productName;
+	}
+
+	@Override
+	public String toString() {
+		return "ElementKoszyka [productId=" + productId + ", productName=" + productName + ", price=" + price
+				+ ", quantity=" + quantity + "]";
+	}
+	
+	@Override
+	public int hashCode() {
+		return Objects.hash(price, productId, productName, quantity);
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		ProductInBasket other = (ProductInBasket) obj;
+		return Objects.equals(price, other.price) && productId == other.productId
+				&& Objects.equals(productName, other.productName) && quantity == other.quantity;
+	}
+
+	public BigDecimal getValue() {
+		return price.multiply(BigDecimal.valueOf(quantity));
+	}
+
+	public void increaseQuantity(int change) {
+		quantity += change;
+	}
+    
+}

PC30-SklepSpring/src/main/java/sklep/controller/ProductController.java

@@ -13,7 +13,10 @@ import org.springframework.validation.BindingResult;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.SessionAttribute;
 
+import sklep.basket.Basket;
 import sklep.model.Product;
 import sklep.repository.ProductRepository;
 import sklep.utils.ExceptionUtils;
@@ -95,5 +98,17 @@ public class ProductController {
 			return "product_form";
 		}
 	}
+	
+	@GetMapping("/products/{id}/add-to-basket")
+	public String addToBasket(
+			@SessionAttribute Basket basket,
+			@PathVariable("id") int productId,
+			@RequestHeader(name="Referer", defaultValue="/products") String adresPowrotu) {
+		Optional<Product> product = productRepository.findById(productId);
+		if(product.isPresent()) {
+			basket.addProduct(product.get());
+		}
+		return "redirect:" + adresPowrotu;
+	}
 
 }

PC30-SklepSpring/src/main/webapp/WEB-INF/templates/product.jsp

@@ -17,6 +17,7 @@
 <p>Stawka VAT: <span class="product-price">${product.vat * 100}%</span></p>
 <p class="product-description">${product.description}</p>
 <div class="action"><a href="/products/${product.productId}/edit">Edytuj</a></div>
+<div class="action"><a href="/products/${product.productId}/add-to-basket">Dodaj do koszyka</a></div>
 </div>
 
 <p><a href="/products">Przejdź do listy produktów</a></p>

PC30-SklepSpring/src/main/webapp/WEB-INF/templates/products.jsp

@@ -8,6 +8,19 @@
 <link rel="stylesheet" type="text/css" href="/styl.css"/>
 </head>
 <body>
+
+<c:if test="${not empty basket and not empty basket.elements}">
+	<div class="basket">
+	<h4>Koszyk</h4>
+	<ul>
+	<c:forEach var="p" items="${basket.elements}">
+		<li>${p.productName}: ${p.quantity} × ${p.price} = <b>${p.value}</b></li>
+	</c:forEach>
+	</ul>
+	<p>Wartość koszyka: ${basket.totalValue}</p>
+	</div>
+</c:if>
+
 <h1>Wszystkie produkty</h1>
 
 <c:forEach var="product" items="${products}">
@@ -16,6 +29,7 @@
 		<p>Cena: <span class="product-price">${product.price}</span></p>
 		<p class="product-description">${product.description}</p>
 	    <div class="action"><a href="/products/${product.productId}/edit">Edytuj</a></div>
+	    <div class="action"><a href="/products/${product.productId}/add-to-basket">Dodaj do koszyka</a></div>
     </div>
 </c:forEach>