[JAVAWEB learning notes] online mall Practice 3: shopping module and order module, javaweb learning notes

[JAVAWEB learning notes] online mall Practice 3: shopping module and order module, javaweb learning notes
Online mall Practice 3

Today's task

• Complete the functions of the shopping module
• Complete the order module function

1.1 shopping module: 1.1.1 function Demonstration:

Product details:

 

Shopping Cart module:

 

1.1.2 code implementation:

1. Click [add to shopping cart] link on the product details page and.

2. Submit to Servlet:

* Quantity of purchased items.

* ID of the purchased item.

3. Store the shopping information to the session.

* Store the information of the shopping cart to the session.

* Encapsulation of shopping item objects (information of each purchased item in the shopping cart)

* Product objects:

* Quantity

* Subtotal

* Encapsulation of Shopping Cart objects (information about all purchased items)

* Collection of shopping items

* Total

4. obtain the information about the shopping cart on the page.

* Displayed on the page.

 

[Encapsulation of shopping items: CartItem]

Public class CartItem {private Product product Product; // private int count of the purchased Product; // Number of purchased private double subtotal; // subtotal public product getProduct () of the purchased Product () {return product;} public void setProduct (Product product) {this. product = product;} public int getCount () {return count;} public void setCount (int count) {this. count = count;} public double getSubtotal () {return count * product. getShop_price ();}/* public void setSubtotal (double subtotal) {this. subtotal = subtotal ;}*/}

 

[Shopping Cart entity: Cart]

Public class Cart {// defines the attributes of a collection of shopping items: the set uses Map, because it is convenient to remove shopping items. use the item id as the Map key // use the shopping item as the Map value. private Map <String, CartItem> map = new LinkedHashMap <String, CartItem> (); // defines the total in the cart: private double total; public Map <String, CartItem> getMap () {return map;} public double getTotal () {return total;} // method: add the shopping item to the shopping cart public void addCart (CartItem cartItem) {// determine whether the shopping item already exists in the shopping cart. string id = cartItem. getProduct (). getPid (); if (map. containsKey (id) {// if it already exists: + the new Quantity Based on the original quantity. total changed. // obtain CartItem _ cartItem = map for the original shopping item in the shopping cart. get (id); _ cartItem. setCount (_ cartItem. getCount () + cartItem. getCount ();} else {// if not, add a new shopping item to the collection. total changed. map. put (id, cartItem);} total + = cartItem. getSubtotal () ;}// method: remove the shopping item public void removeCart (String id) from the shopping cart {// remove the selected element from the map. // CartItem cartItem = map. get (id); CartItem cartItem = map. remove (id); // total-remove the subtotal of the shopping item total-= cartItem. getSubtotal () ;}// method: Clear the public void clearCart () {// clear the map set. map. clear (); // set the summary to 0. total = 0 ;}}

 

 

 

[Click the link to add to the shopping cart on the shopping details page]

Public String addCart (HttpServletRequest req, HttpServletResponse resp) {// receiving parameter: String pid = req. getParameter ("pid"); int count = Integer. parseInt (req. getParameter ("count"); try {// encapsulate shopping items: CartItem cartItem = new CartItem (); // item object: Query items by item ID. productService productService = (ProductService) BeanFactory. getBean ("productService"); Product product = productService. findById (pid); cartItem. setProduct (product); cartItem. setCount (count); // call the method to add to the shopping Cart in the shopping cart: // Cart = new cart (); cart Cart = getCart (req); cart. addCart (cartItem); resp. sendRedirect (req. getContextPath () + "/jsp/cart. jsp ");} catch (Exception e) {e. printStackTrace (); throw new RuntimeException ();} return null ;}

Click "clear shopping cart" on the shopping cart page]

Public String clearCart (HttpServletRequest req, HttpServletResponse resp) {// get the cart object. cart cart = getCart (req); // call the method in the shopping cart: Cart. clearCart (); try {resp. sendRedirect (req. getContextPath () + "/jsp/cart. jsp ");} catch (Exception e) {e. printStackTrace (); throw new RuntimeException ();} return null ;}

 

Click Delete link on the shopping cart page]

Public String removeCart (HttpServletRequest req, HttpServletResponse resp) {try {// receiving parameter: String pid = req. getParameter ("pid"); // get the Cart: cart = getCart (req); Cart. removeCart (pid); // page Jump resp. sendRedirect (req. getContextPath () + "/jsp/cart. jsp ");} catch (Exception e) {e. printStackTrace (); throw new RuntimeException ();} return null ;}

 

1.2 Order module: 1.2.1 function Demonstration:

 

 

1.2.2 code implementation: 1.2.2.1 create tables and entities:

CREATE TABLE `orders` (  `oid` varchar(32) NOT NULL,  `ordertime` datetime DEFAULT NULL,  `total` double DEFAULT NULL,  `state` int(11) DEFAULT NULL,  `address` varchar(30) DEFAULT NULL,  `name` varchar(20) DEFAULT NULL,  `telephone` varchar(20) DEFAULT NULL,  `uid` varchar(32) DEFAULT NULL,  PRIMARY KEY (`oid`)) ENGINE=InnoDB DEFAULT CHARSET=utf8; CREATE TABLE `orderitem` (  `itemid` varchar(32) NOT NULL,  `count` int(11) DEFAULT NULL,  `subtotal` double DEFAULT NULL,  `pid` varchar(32) DEFAULT NULL,  `oid` varchar(32) DEFAULT NULL,  PRIMARY KEY (`itemid`),  KEY `fk_0001` (`pid`),  KEY `fk_0002` (`oid`),  CONSTRAINT `fk_0001` FOREIGN KEY (`pid`) REFERENCES `product` (`pid`),  CONSTRAINT `fk_0002` FOREIGN KEY (`oid`) REFERENCES `orders` (`oid`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;

 

 

1.2.2.2 generate an order:

Click Submit order on the shopping cart page]

Submit to Servlet:

* Encapsulate order and order items.

* Call the Business Layer

* Clear the shopping cart

* Page Jump