Feature lecture 3

src/main/java/com/es/phoneshop/model/product/DAO.java → src/main/java/com/es/phoneshop/model/DAO.java

@@ -1,4 +1,4 @@
-package com.es.phoneshop.model.product;
+package com.es.phoneshop.model;
 
 import java.util.List;
 import java.util.Optional;

src/main/java/com/es/phoneshop/model/cart/entity/Cart.java

@@ -0,0 +1,33 @@
+package com.es.phoneshop.model.cart.entity;
+
+import com.es.phoneshop.model.product.entity.Product;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Cart {
+    //LinkedHashMap would be better?
+    //Can Entity-Bean contain some business-logic?
+    private List<CartItem> cartItems;
+
+    public Cart() {
+        this.cartItems = new ArrayList<>();
+    }
+
+    public List<CartItem> getItems() {
+        return this.cartItems;
+    }
+
+    public void add(Product product, int quantity) {
+        cartItems.add(new CartItem(product, quantity));
+    }
+
+    public void add(CartItem cartItem){
+        cartItems.add(cartItem);
+    }
+
+    @Override
+    public String toString() {
+        return "Cart[" + cartItems + ']';
+    }
+}

src/main/java/com/es/phoneshop/model/cart/entity/CartItem.java

@@ -0,0 +1,30 @@
+package com.es.phoneshop.model.cart.entity;
+
+import com.es.phoneshop.model.product.entity.Product;
+
+public class CartItem {
+    private Product product;
+
+    private int quantity;
+
+    public CartItem(Product product, int quantity) {
+        this.product = product;
+        this.quantity = quantity;
+    }
+
+    public Product getProduct() {
+        return product;
+    }
+
+    public int getQuantity() {
+        return quantity;
+    }
+
+    public void setQuantity(int quantity) {
+        this.quantity = quantity;
+    }
+
+    public void increaseQuantity(int quantity){
+        this.quantity+=quantity;
+    }
+}

src/main/java/com/es/phoneshop/model/cart/service/CartService.java

@@ -0,0 +1,12 @@
+package com.es.phoneshop.model.cart.service;
+
+import com.es.phoneshop.model.cart.entity.Cart;
+import com.es.phoneshop.web.exceptions.OutOfStockException;
+
+public interface CartService<SessionResource> {
+
+    Cart getCart(SessionResource sessionResource);
+
+    void add(Cart cart, Long productId, int quantity) throws OutOfStockException;
+
+}

src/main/java/com/es/phoneshop/model/cart/service/HttpServletCartService.java

@@ -0,0 +1,67 @@
+package com.es.phoneshop.model.cart.service;
+
+import com.es.phoneshop.model.cart.entity.Cart;
+import com.es.phoneshop.model.cart.entity.CartItem;
+import com.es.phoneshop.model.product.dao.ArrayListProductDao;
+import com.es.phoneshop.model.product.dao.ProductDao;
+import com.es.phoneshop.model.product.entity.Product;
+import com.es.phoneshop.web.exceptions.OutOfStockException;
+
+import javax.servlet.http.HttpServletRequest;
+import java.util.NoSuchElementException;
+import java.util.Optional;
+
+public enum HttpServletCartService implements CartService<HttpServletRequest> {
+    INSTANCE;
+
+    private static final String CART_SESSION_ATTRIBUTE = HttpServletCartService.class.getName() + ".cart";
+
+    private final ProductDao productDao = ArrayListProductDao.getInstance();
+
+    @Override
+    public Cart getCart(HttpServletRequest request) {
+        //i heard about AtomicReference solution of thread safety problem but it seems to be next level of knowledge
+        synchronized (request.getSession()) {
+            Cart cart = (Cart) request.getSession().getAttribute(CART_SESSION_ATTRIBUTE);
+            if (cart == null) {
+                request.getSession().setAttribute(CART_SESSION_ATTRIBUTE, cart = new Cart());
+            }
+            return cart;
+        }
+    }
+
+    @Override
+    public void add(Cart cart, Long productId, int quantity) throws OutOfStockException {
+        //some valid-checking should be here
+        synchronized (cart) {
+            try {
+                Product product = productDao.get(productId).get();
+
+                if (quantity > product.getStock()) {
+                    throw new OutOfStockException();
+                }
+
+                Optional<CartItem> optionalCartItem = findItemInCart(cart, productId);
+                if (optionalCartItem.isPresent()) {
+                    var cartItem = optionalCartItem.get();
+                    if (product.getStock() >= cartItem.getQuantity() + quantity) {
+                        cartItem.increaseQuantity(quantity);
+                    } else {
+                        throw new OutOfStockException();
+                    }
+                } else {
+                    cart.add(product, quantity);
+                }
+            } catch (NoSuchElementException e) {
+                throw new NoSuchElementException(String.valueOf(productId));
+            }
+        }
+    }
+
+    private Optional<CartItem> findItemInCart(Cart cart, Long productId) {
+        return cart.getItems()
+                .stream()
+                .filter(existingCartItem -> existingCartItem.getProduct().getId().equals(productId))
+                .findFirst();
+    }
+}

src/test/java/com/es/phoneshop/model/product/ArrayListProductDaoTest.java

@@ -1,5 +1,8 @@
 package com.es.phoneshop.model.product;
 
+import com.es.phoneshop.model.product.dao.ArrayListProductDao;
+import com.es.phoneshop.model.product.dao.TestableSingletonProductDao;
+import com.es.phoneshop.model.product.entity.Product;
 import org.junit.Before;
 import org.junit.Test;
 

src/test/java/com/es/phoneshop/model/product/ProductServiceImplTest.java

@@ -1,6 +1,13 @@
 package com.es.phoneshop.model.product;
 
 import static org.junit.Assert.*;
+
+import com.es.phoneshop.model.product.dao.ArrayListProductDao;
+import com.es.phoneshop.model.product.dao.TestableSingletonProductDao;
+import com.es.phoneshop.model.product.entity.Product;
+import com.es.phoneshop.model.product.service.ProductServiceImpl;
+import com.es.phoneshop.model.product.sortEnums.SortField;
+import com.es.phoneshop.model.product.sortEnums.SortOrder;
 import org.junit.Before;
 import org.junit.Test;
 

src/test/java/com/es/phoneshop/web/ProductDemoDataServletContextListenerTest.java

@@ -1,10 +1,8 @@
 package com.es.phoneshop.web;
 
-import com.es.phoneshop.model.product.ArrayListProductDao;
-import com.es.phoneshop.model.product.Product;
-import com.es.phoneshop.model.product.ProductDao;
-import com.es.phoneshop.model.product.TestableSingletonProductDao;
-import org.junit.After;
+import com.es.phoneshop.model.product.dao.ArrayListProductDao;
+import com.es.phoneshop.model.product.entity.Product;
+import com.es.phoneshop.model.product.dao.TestableSingletonProductDao;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;

src/test/java/com/es/phoneshop/web/ProductDetailsPageServletTest.java

@@ -1,9 +1,8 @@
 package com.es.phoneshop.web;
 
-import com.es.phoneshop.model.product.ArrayListProductDao;
-import com.es.phoneshop.model.product.Product;
-import com.es.phoneshop.model.product.TestableSingletonProductDao;
-import org.junit.After;
+import com.es.phoneshop.model.product.dao.ArrayListProductDao;
+import com.es.phoneshop.model.product.entity.Product;
+import com.es.phoneshop.model.product.dao.TestableSingletonProductDao;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -13,7 +12,6 @@
 import javax.servlet.*;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-import java.awt.image.AreaAveragingScaleFilter;
 import java.io.IOException;
 import java.math.BigDecimal;
 import java.util.Currency;