一個購物車的demo，數(shù)據(jù)時死的笔诵。用mvc結(jié)構(gòu)寫
QQ截圖20170627220828.png
上面的是購物車中的結(jié)構(gòu)目錄
首先建立數(shù)據(jù)源 用死數(shù)據(jù)進行模擬
/**
* 模擬數(shù)據(jù)庫的數(shù)據(jù)
*/
public class MyDb {
private static Map<String, Book> map=new LinkedHashMap();
static{
map.put("1", new Book("1","javaweb開發(fā)","老張",20,"一本經(jīng)典的書"));
map.put("2", new Book("2","jdbc開發(fā)","李勇",30,"一本jdbc的書"));
map.put("3", new Book("3","spring開發(fā)","老黎",50,"一本相當(dāng)經(jīng)典的書"));
map.put("4", new Book("4","hibernate開發(fā)","老佟",56,"一本佟佟的書"));
map.put("5", new Book("5","struts開發(fā)","老畢",40,"一本經(jīng)典的書"));
map.put("6", new Book("6","ajax開發(fā)","老張",50,"一本老張的書"));
}
/**
* 得到所有的書本的信息
* @return
*/
public static Map<String, Book> getAll() {
return map;
}
}
書本的實體類
/**
* 書的實體類
*/
public class Book {
private String id;
private String name;
private String author;
private double price;
private String description;
public Book() {
// TODO Auto-generated constructor stub
}
public Book(String id, String name, String author, double price, String description) {
super();
this.id = id;
this.name = name;
this.author = author;
this.price = price;
this.description = description;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
接下來是 Dao
/**
* 根據(jù) 需求來和 數(shù)據(jù)庫 打交道
*/
public class BookDao {
/**
* 根據(jù)book的id來獲取書
*/
public Book find(String id){
return MyDb.getAll().get(id);
}
/**
* 獲取所有的書本信息 以map的方式給你
*/
public Map getAll(){
return MyDb.getAll();
}
}
業(yè)務(wù)處理類
/**
* 書本業(yè)務(wù)的邏輯 用于和 dao層 和 view進行交互數(shù)據(jù)
*/
public class BusinessService {
BookDao bookDao=new BookDao();
/**
* 得到所有的書本信息
* @return
*/
public Map getAll(){
return bookDao.getAll();
}
/**
* 買書
*/
public void buybook(String bookid, Cart cart) {
Book book = bookDao.find(bookid);
cart.add(book);
}
/**
* 清空購物車
* @param cart
* @throws CartNotFoundException
*/
public void clear(Cart cart) throws CartNotFoundException{
if (cart ==null) {
throw new CartNotFoundException();
}
cart.clear();
}
/**
* 刪除購物車中的商品
* @param cart
* @param bookid
* @throws CartNotFoundException
*/
public void delete(Cart cart,String bookid) throws CartNotFoundException{
if(cart==null){
throw new CartNotFoundException();
}
cart.getMap().remove(bookid);
}
/**
* 將 商品的數(shù)量進行改變
* @param cart
* @param bookid
* @param quantity
*/
public void updateCart(Cart cart,String bookid,int quantity) throws CartNotFoundException{
if(cart==null){
throw new CartNotFoundException();
}
CartItem cartItem=cart.getMap().get(bookid);
cartItem.setQuantity(quantity);
}
}
展示書本列表的 servlet
/**
* 書本的列表頁
*/
public class ListBookServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//將數(shù)據(jù)中的書本信息取出 給request 域中 方便jsp中調(diào)用顯示
BusinessService businessService=new BusinessService();
Map<String, Book> map=businessService.getAll();
request.setAttribute("map", map);
request.getRequestDispatcher("/WEB-INF/jsp/listbook.jsp").forward(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
展示書本的jsp
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>書本的列表</title>
</head>
<body style="text-align: center;">
<br/>
<h2>書籍列表</h2>
<br/><br/>
<table border="1" width="80%">
<tr>
<td>書籍編號</td>
<td>書名</td>
<td>作者</td>
<td>售價</td>
<td>描述</td>
<td>操作</td>
</tr>
<%-- Set<Map.Entry<String,Book>> 每次循環(huán)出來的就是這個--%>
<c:forEach var="me" items="${map}">
<tr>
<td>${me.key}</td>
<td>${me.value.name}</td>
<td>${me.value.author}</td>
<td>${me.value.price}</td>
<td>${me.value.description}</td>
<td>
<a href="${pageContext.request.contextPath}/BuyServlet?bookid=${me.key}">購買</a>
</td>
</tr>
</c:forEach>
</table>
</body>
</html>
購買書本后的servlet
/**
* 點擊購買按鈕調(diào)到此界面進行處理
*/
public class BuyServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String bookid=request.getParameter("bookid");
Cart cart=(Cart) request.getSession().getAttribute("cart");
if (cart==null) {
cart=new Cart();
request.getSession().setAttribute("cart", cart);
}
//將商品加入購物車中
BusinessService businessService=new BusinessService();
businessService.buybook(bookid, cart);
//展示購買過的商品
request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
展示購買的商品的 servlet
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>購買過的商品</title>
<script type="text/javascript">
/* 清空購物車 */
function clearcart() {
var isClear=window.confirm("您確定要清空購物車嗎眉踱？诞吱？");
if(isClear){
window.location.href="${pageContext.request.contextPath}/ClearCartServlet";
}
}
/*更新 顯示的數(shù)據(jù)*/
function updateCart(input, id){
// input 輸入的內(nèi)容 id 是更新的是哪個 商品
var quantity=input.value;
var b = window.confirm("請確認(rèn)改為：" + quantity);
if(b) {
/* 將修改 的構(gòu)成車中商品的id和修改成的數(shù)量給servlet */
window.location.href="${pageContext.request.contextPath}/UpdateCartServlet?bookid="+id + "&quantity=" + quantity;
}
}
</script>
</head>
<body style="text-align: center;">
<br/>
<h2>購物車列表</h2>
<br/><br/>
<!-- 當(dāng)購物車不是空 -->
<c:if test="${!empty(cart.map)}">
<table border="1" width="80%">
<tr>
<td>書名</td>
<td>作者</td>
<td>單價</td>
<td>數(shù)量</td>
<td>小計</td>
<td>操作</td>
</tr>
<!-- Set<Map.Entry<String,CarItem>> 每次循環(huán)出來的就是這個 -->
<c:forEach var="me" items="${cart.map }">
<tr>
<td>${me.value.book.name} </td>
<td>${me.value.book.author} </td>
<td>${me.value.book.price} </td>
<td>
<input type="text" name="quantity" value="${me.value.quantity}" style="width: 60px" onchange="updateCart(this,${me.value.book.id })">
</td>
<td>${me.value.quantity} </td>
<td>${me.value.price }</td>
<td>
<a href="${pageContext.request.contextPath}/DeleteServlet?bookid=${me.value.book.id}">刪除</a>
</td>
</tr>
</c:forEach>
<tr>
<td colspan="2">
<a href="javascript:clearcart()">清空購物車</a>
</td>
<td colspan="2">合計</td>
<td colspan="2">${cart.price}</td>
</tr>
</table>
</c:if>
<c:if test="${empty(cart.map)}">
對不起慈参，您還沒有購買任何商品
</c:if>
</body>
</html>
清空購物車的 servlet
/**
* 清空購物車哦
*/
public class ClearCartServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Cart cart= (Cart) request.getSession().getAttribute("cart");
BusinessService businessService=new BusinessService();
try {
businessService.clear(cart);
request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response);
} catch (CartNotFoundException e) {
request.setAttribute("message","對不起，您還沒有購買任何商品!!!");
request.getRequestDispatcher("/message.jsp").forward(request, response);
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
刪除 商品的 sevlet
/**
* 刪除 購物列表中的數(shù)據(jù)
*/
public class DeleteServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String bookid=request.getParameter("bookid");
//將次數(shù)的id從購物車進行刪除
Cart cart=(Cart) request.getSession().getAttribute("cart");
BusinessService businessService=new BusinessService();
try {
businessService.delete(cart, bookid);
request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response);
} catch (CartNotFoundException e) {
request.setAttribute("message","對不起备绽，您還沒有購買任何商品!!!");
request.getRequestDispatcher("/message.jsp").forward(request, response);
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
當(dāng)在購買過的商品中進行修改商品的數(shù)量的時候
/**
* 當(dāng)修改購買商品的數(shù)量 進行操作的 servlet
*/
public class UpdateCartServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String bookid=request.getParameter("bookid");
String quantity=request.getParameter("quantity");
BusinessService businessService=new BusinessService();
Cart cart=(Cart)request.getSession().getAttribute("cart");
int q=Integer.parseInt(quantity);
try {
businessService.updateCart(cart, bookid, q);
request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response);
} catch (CartNotFoundException e) {
request.setAttribute("message","對不起，您還沒有購買任何商品!!!");
request.getRequestDispatcher("/message.jsp").forward(request, response);
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
購物車的實體
/**
* 購物車
*/
public class Cart {
/**
* 用于存儲 購車車中的信息 key--- id value -- 書的信息
*/
private Map<String,CartItem> map = new LinkedHashMap();
private double price; //購車中總的價格
/**
* 向購物車中添加 書本
* @param book
*/
public void add(Book book)
{
//根據(jù)書本的id 知道 購物車中是否已經(jīng)存入該商品
CartItem cartItem= map.get(book.getId());
if (cartItem!=null) {
//已經(jīng)有該商品了
cartItem.setQuantity(cartItem.getQuantity()+1);
}else{
//該商品還沒有 需要進行創(chuàng)建
cartItem=new CartItem();
cartItem.setBook(book);
cartItem.setQuantity(1);
map.put(book.getId(), cartItem);
}
}
/**
* 獲取購物車
* @return
*/
public Map<String, CartItem> getMap(){
return map;
}
public void setMap(Map<String, CartItem> map) {
this.map = map;
}
/**
* 得到總價格
* @return
*/
public double getPrice(){
double totalprice =0;
for(Map.Entry<String, CartItem> me:map.entrySet()){
CartItem cartItem=me.getValue();
totalprice+=cartItem.getPrice();
}
return totalprice;
}
/**
* 清空數(shù)據(jù)
*/
public void clear(){
getMap().clear();
}
}
public class CartItem {
private Book book;
private int quantity;//購買的數(shù)量
private double price;
public Book getBook() {
return book;
}
public void setBook(Book book) {
this.book = book;
}
public int getQuantity() {
return quantity;
}
public void setQuantity(int quantity) {
this.quantity = quantity;
}
public double getPrice() {
return this.book.getPrice()*this.quantity;
}
public void setPrice(double price) {
this.price = price;
}
}
