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| author | Sven Eisenhauer <sven@sven-eisenhauer.net> | 2023-11-10 15:11:48 +0100 |
|---|---|---|
| committer | Sven Eisenhauer <sven@sven-eisenhauer.net> | 2023-11-10 15:11:48 +0100 |
| commit | 33613a85afc4b1481367fbe92a17ee59c240250b (patch) | |
| tree | 670b842326116b376b505ec2263878912fca97e2 /Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/impl/session/CartBean.java | |
| download | Studium-master.tar.gz Studium-master.tar.bz2 | |
Diffstat (limited to 'Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/impl/session/CartBean.java')
| -rw-r--r-- | Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/impl/session/CartBean.java | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/impl/session/CartBean.java b/Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/impl/session/CartBean.java new file mode 100644 index 0000000..d5e2b1b --- /dev/null +++ b/Master/Reference Architectures and Patterns/EJB 3.0 Code/Gerald Examples/src/examples/shop/impl/session/CartBean.java @@ -0,0 +1,320 @@ +package examples.shop.impl.session;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import javax.ejb.Remote;
+import javax.ejb.Remove;
+import javax.ejb.Stateful;
+import javax.jms.Connection;
+import javax.jms.ConnectionFactory;
+import javax.jms.Destination;
+import javax.jms.JMSException;
+import javax.jms.MessageProducer;
+import javax.jms.Session;
+import javax.jms.TextMessage;
+import javax.naming.Context;
+import javax.naming.InitialContext;
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+
+import examples.shop.impl.entity.Customer;
+import examples.shop.impl.entity.LineItem;
+import examples.shop.impl.entity.Order;
+import examples.shop.impl.entity.Product;
+import examples.shop.logic.Cart;
+
+/**
+ * This stateful session bean represents a cart which a customer is
+ * working on. A cart is a set of products that the customer is
+ * interested in, but has not committed to buying yet.
+ *
+ * A cart consists of a series of line items. Each line item
+ * represents one particular product the customer wants, as well as a
+ * quantity and discount for that product.
+ *
+ * The distinction between a cart and an order is that a quote is only
+ * temporary and in-memory (hence a stateful session bean), whereas an
+ * order is a persistent record (hence an entity). The cart bean
+ * knows how to transform itself into an order (via the purchase()
+ * method).
+ */
+
+@Stateful
+@Remote(Cart.class)
+public class CartBean implements Cart {
+
+ /**
+ * The shopping cart owner
+ */
+ private String owner;
+
+ /**
+ * The shopping cart contents - a vector of LineItems
+ */
+ private List<LineItem> contents = new ArrayList();
+
+ /**
+ * The subtotal (price before taxes) of the goods
+ */
+ private double subTotal;
+
+ /**
+ * The taxes on the goods
+ */
+ private double taxes;
+
+ @PersistenceContext
+ private EntityManager manager;
+
+ public CartBean() {
+ }
+
+ /**
+ * Get method for the shopping cart owner's name
+ *
+ * @return shopping cart owner
+ */
+ public String getOwner() {
+ return owner;
+ }
+
+ /**
+ * Set method for the shopping cart owner's name
+ *
+ * @param shopping
+ * cart owner
+ */
+ public void setOwner(String owner) {
+ this.owner = owner;
+ }
+
+ /**
+ * Adds an item to the shopping cart
+ *
+ * @param shopping
+ * cart lineitem
+ */
+ public void add(LineItem lineItem) {
+ /*
+ * Search for an exiting line item in the cart that match
+ * the productID passed in.
+ */
+ for (Iterator<LineItem> iter = contents.iterator(); iter.hasNext();) {
+ LineItem item = iter.next();
+ Product product = item.getProduct();
+
+ if (product != null
+ && product.getProductID().equals(
+ lineItem.getProduct().getProductID())) {
+ // found one, modify that line item's quantity and return
+ item.setQuantity(item.getQuantity() + lineItem.getQuantity());
+ return;
+ }
+ }
+
+ /*
+ * Did not find a match, so add the line item as new.
+ */
+ contents.add(lineItem);
+ }
+
+ /**
+ * Changes the quantities of contents in the shopping cart
+ *
+ * @param product
+ * Id
+ * @param number
+ * of items.
+ */
+ public void modify(String productID, int quantity) throws Exception {
+ System.out.println("CartBean.modify()");
+
+ /*
+ * Search for a lineitem in the cart that match the productID passed in.
+ * If found, modify that lineitem.
+ */
+ for (Iterator<LineItem> iter = contents.iterator(); iter.hasNext();) {
+ LineItem item = iter.next();
+ Product product = item.getProduct();
+ if (product != null && product.getProductID().equals(productID)) {
+ item.setQuantity(quantity);
+ if (quantity == 0) {
+ iter.remove();
+ }
+ return;
+ }
+ }
+ throw new Exception("CartBean.modify() error: Could not find product "
+ + productID);
+ }
+
+ /**
+ * Returns all the shopping cart line items
+ *
+ * @return A collection of Cart LineItems
+ */
+ public List<LineItem> getAll() {
+ return contents;
+ }
+
+ /**
+ * @return the subtotal price which has been previously set by
+ * setSubtotal().
+ */
+ public double getSubtotal() {
+ return subTotal;
+ }
+
+ /**
+ * Sets the subtotal price.
+ * @param subTotal the subtotal price
+ */
+ public void setSubtotal(double subTotal) {
+ this.subTotal = subTotal;
+ }
+
+ /**
+ * @return the taxes computed for this Cart.
+ */
+ public double getTaxes() {
+ return taxes;
+ }
+
+ /**
+ * Sets the taxes for this Cart.
+ */
+ public void setTaxes(double taxes) {
+ System.out.println("CartBean.setTaxes(): " + taxes);
+ this.taxes = taxes;
+ }
+
+ /**
+ * Get the total price. The total Price is computed from:
+ * <ol>
+ * <li>Subtotal price
+ * <li>Tax
+ * </ol>
+ * @return the total price.
+ */
+ public double getTotalPrice() {
+ return subTotal + taxes;
+ }
+
+ /**
+ * Empties the shopping cart
+ */
+ public void clear() {
+ contents.clear();
+ }
+
+ /**
+ * Purchases this cart. The cart will create an order in the database
+ * and return the order ID as a confirmation number.
+ *
+ * @return The Order confirmation number
+ */
+ public String purchase() {
+ System.out.println("CartBean.purchase()");
+ Customer customer = manager.find(Customer.class, owner);
+
+ /*
+ * Create the order entity
+ */
+ Order order = new Order();
+ String orderID = makeUniqueID();
+ order.init(orderID, customer, Order.Status.Unverified, subTotal, taxes);
+ order.setLineItems(prepareContents());
+ manager.persist(order);
+
+ /*
+ * Sends the JMS message to the topic
+ */
+ try {
+ sendMessage(orderID);
+ } catch (Exception e) {
+ // TODO Auto-generated catch block
+ e.printStackTrace();
+ }
+
+ /*
+ * Return the order ID
+ */
+ return orderID;
+ }
+
+ /**
+ * Sends a JMS message to a destination (Queue or Topic)
+ *
+ * @param a
+ * message string, in this case orderId
+ */
+ private void sendMessage(String text) throws Exception {
+ Connection connection = null;
+ MessageProducer producer = null;
+ Session session = null;
+
+ try {
+ Context jndiContext = new InitialContext();
+ ConnectionFactory connectionFactory = (ConnectionFactory) jndiContext
+ .lookup("jms/QueueConnectionFactory");
+ Destination destination = (Destination) jndiContext
+ .lookup("jms/OrderQueue");
+ connection = connectionFactory.createConnection();
+ session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
+ producer = session.createProducer(destination);
+
+ connection.start();
+ TextMessage msg = session.createTextMessage();
+ msg.setText(text);
+ producer.send(msg);
+ } catch (Exception ex) {
+ throw ex;
+ } finally {
+ if (connection != null) {
+ try {
+ producer.close();
+ connection.close();
+ session.close();
+ } catch (JMSException e) {
+ // ignore
+ }
+ }
+ }
+ }
+
+ /**
+ * Generates primary keys for line items and loads the products
+ * into the persistence context.
+ */
+
+ private List<LineItem> prepareContents() {
+ for (Iterator<LineItem> iter = contents.iterator(); iter.hasNext();) {
+ LineItem lineItem = iter.next();
+ Product p = manager.find(Product.class, lineItem.getProduct()
+ .getProductID());
+ lineItem.setProduct(p);
+ lineItem.setId(makeUniqueID());
+ }
+ return contents;
+ }
+
+ /**
+ * Returns a unique Id based on current time. Can be removed
+ * when AUTO key generation works in Glassfish *
+ */
+ private String makeUniqueID() {
+ String id = new Long(System.nanoTime()).toString();
+ System.out.println("makeUniqueID: " + id);
+ return id;
+ }
+
+ /**
+ * Removes this quote, and hence all client-
+ * specific state.
+ */
+ @Remove
+ public void remove() {
+ }
+}
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