jsp电子商务购物车之四 数据库存储篇
2024-09-24 05:04:33
为了方便用户下次登录，仍然可以看到自己的购物车内容，所以，需要在数据库存储相应的购物车项目，本处增加购物车项表;uid和bid是复合主键。
package com.cart.entity;
//购物车的单项;
public class CartItem {
int uid;
int bid; //外键;理解为商品id，这样可以任意;
int count;
String bookname;//方便存储
double price; //单项价格;
private String image;
public int getUid() {
return uid;
}
public void setUid(int uid) {
this.uid = uid;
}
public int getBid() {
return bid;
}
public void setBid(int bid) {
this.bid = bid;
}
public int getCount() {
return count;
}
public void setCount(int count) {
this.count = count;
}
public String getBookname() {
return bookname;
}
public void setBookname(String bookname) {
this.bookname = bookname;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
//有一个方法，获得总价;
public double getTotalPrice(){
return price*count;
}
public void setImage(String image) {
this.image = image;
}
public String getImage() {
return image;
}
}
//增加购物项
public interface CartDao {
public int addCartItem(CartItem cartItem);
public boolean isExists(int uid,int bid);
public int updateCartItemCount(CartItem cartItem);
public Map<Integer,CartItem> getCartItem(int uid);
public CartItem findCartItemById(int uid,int bid);
}
package com.cart.dao.impl;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;
import com.cart.dao.CartDao;
import com.cart.entity.Book;
import com.cart.entity.CartItem;
import com.cart.util.DaoFactory;
public class CartDaoImpl implements CartDao {
Connection con = null;
PreparedStatement pstmt = null;
ResultSet rs=null;
public int addCartItem(CartItem cartItem) {
String sql="insert cartitem values(?,?,?,?,?,?)";
int result=-1;
try {
con=DaoFactory.getConnection();
Object[]params={cartItem.getUid(),cartItem.getBid(),cartItem.getBookname(),cartItem.getPrice(),cartItem.getCount(),cartItem.getImage()};
pstmt=con.prepareStatement(sql);
DaoFactory.setParams(pstmt, params);
result=DaoFactory.executeUpdate(sql, params);
} catch (Exception e) {
e.printStackTrace();
}finally{
DaoFactory.closeAll(null, pstmt, con);
}
return result;
}
/* 根据uid和bid进行判断是否已经有物品存在于否则，有则返回true，不用再插入了;
* @see com.cart.dao.CartDao#isExists(int, int)
*/
public boolean isExists(int uid,int bid) {
String sql="select uid,bid from cartitem where uid=? and bid=?";
boolean result=false;
try {
con=DaoFactory.getConnection();
pstmt=con.prepareStatement(sql);
Object[] params={uid,bid};
DaoFactory.setParams(pstmt, params);
rs=pstmt.executeQuery();
if(rs.next()){
return true;
}
} catch (Exception e) {
e.printStackTrace();
}finally{
DaoFactory.closeAll(null, pstmt, con);
}
return result;
}
public int updateCartItemCount(CartItem cartItem) {
String sql="update cartitem set count=? where uid=? and bid=?";
int result=-1;
try {
con=DaoFactory.getConnection();
pstmt=con.prepareStatement(sql);
Object[] params={cartItem.getCount(),cartItem.getUid(),cartItem.getBid()};
DaoFactory.setParams(pstmt, params);
result=pstmt.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
}finally{
DaoFactory.closeAll(null, pstmt, con);
}
return result;
}
public Map<Integer, CartItem> getCartItem(int uid) {
String sql="select * from cartitem where uid=?";
Map<Integer,CartItem>cartItems=new HashMap<Integer,CartItem>();
try {
con=DaoFactory.getConnection();
pstmt=con.prepareStatement(sql);
Object[] params={uid};
DaoFactory.setParams(pstmt, params);
rs=pstmt.executeQuery();
while(rs.next()){
CartItem item=new CartItem();
item.setUid(uid);
int bid=rs.getInt("bid");
item.setBid(bid);
item.setBookname(rs.getString("bookname"));
item.setCount(rs.getInt("count"));
item.setPrice(rs.getDouble("price"));
item.setImage(rs.getString("image"));
cartItems.put(bid,item);//bid，后面是对应的item;
}
} catch (Exception e) {
e.printStackTrace();
}finally{
DaoFactory.closeAll(null, pstmt, con);
}
return cartItems;
}
public CartItem findCartItemById(int uid,int bid) {
String sql = "select * from cartitem where uid=? and bid=?";
ResultSet rs = null;
CartItem item = null;
try {
con=DaoFactory.getConnection();
pstmt=con.prepareStatement(sql);
Object[] params={uid,bid};
DaoFactory.setParams(pstmt, params);
rs=pstmt.executeQuery();
if(rs.next()){
item = new CartItem();
item.setUid(rs.getInt("uid"));
item.setBookname(rs.getString("bookname"));
item.setBid(rs.getInt("bid"));
item.setCount(rs.getInt("count"));
item.setPrice(rs.getDouble("price"));
item.setImage(rs.getString("image"));
}
} catch (Exception e) {
e.printStackTrace();
}
finally{
DaoFactory.closeAll(rs, pstmt, con);
}
return item;
}
}
package com.cart.web;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import com.cart.entity.Book;
import com.cart.entity.Cart;
import com.cart.entity.CartItem;
import com.cart.entity.Userinfo;
import com.cart.service.BookService;
import com.cart.service.CartService;
public class BuyServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
resp.setContentType("text/html;charset=utf-8");
HttpSession session=req.getSession();
Userinfo userinfo =(Userinfo)req.getSession().getAttribute("userinfo");
int bid=Integer.parseInt(req.getParameter("id"));//这个就是bid
//通过Service来获得book对象;
BookService bookService=new BookService();
Book book=bookService.getBookById(bid);
//下一步，点击购物的时候，获得bid，+uid;1 1，则调出自己的购物车列表;
CartService cartService=new CartService();
int uid=userinfo.getId();
Map<Integer,CartItem> cart=(Map<Integer,CartItem>)session.getAttribute("cart");
//1.是已经存在于数据库的;
if(cartService.isExists(uid, bid));//如果没有登录，已经过滤了;
{
//如果已经存在相当的数据，则应该读取出来到CartItem
cart=cartService.getCartItem(uid);
}
//2.没有买过的；也没有登录过的；则新创建;
//cart = (Map<Integer,CartItem>)session.getAttribute("cart");
if(cart==null){
cart=new HashMap<Integer,CartItem>();//id以及CartItem对象,这样购物车想可以是任意商品
session.setAttribute("cart",cart);
}
//3.利用session登录，加入购物车了；但是没有到数据库的;
//
CartItem cartItem=cart.get(bid); //有4，但是数据库没有;
if (cartItem == null) {
cartItem=new CartItem();
cartItem.setUid(userinfo.getId());
cartItem.setBid(bid);// 此id为book的id;
cartItem.setPrice(book.getPrice()); // 设置购物车项，图书的价格,升级要考虑会员的vip
cartItem.setBookname(book.getBookname());
cartItem.setCount(1); // 购物项完毕之后，需要将购物项放到一个购物车篮子中;
cartItem.setImage(book.getImage());
} else {
// 判断是否已经是最后一本书;数量大于获得数量,其他的不能再加数量了
if(book.getStock()>cartItem.getCount()){
cartItem.setCount(cartItem.getCount()+1);
}
}
//目前的问题是如果已经存在于数据库了，没有把cart的值给获取过来;
cart.put(bid, cartItem);// 将购物车选项加进来!!!
//同时设置购物车项进数据库，方便下次客户进来判断;
//思路有问题f
cartService.addCartItem(cartItem);
//是否可以直接将cart插入到数据库中，对应某个该用户的id;
session.setAttribute("cart", cart); //加入session用jstl读取；
resp.sendRedirect("show_cart.jsp");
//需要将购物车项加入到数据库中;
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
this.doGet(req, resp);
}
}
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'cart.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<link rel="stylesheet" href="css/style.css" type="text/css"></link>
<script type="text/javascript" src="js/jquery-1.7.2.min.js"></script>
<script type="text/javascript">
function jian(id){
if($("#count"+id).val()==1){
//采用淘宝模式，如果低于1，则不用提示，直接不可用;
$("#count"+id).prev().attribute("disabled","disabled");
return;
}
$.ajax({
url:'ChangeCartCountServlet',
type:'post',
dataType:'text',
data:{
bookid:id,
count:parseInt($("#count"+id).val())-1 // -1
},
success:function(data){
var price = $("#price"+id).html();
$("#count"+id).val(parseInt($("#count"+id).val())-1);
$("#sum"+id).val("￥"+price*$("#count"+id).val());
calcTotal();
}
});
}
function add(id){
$.ajax({
url:'ChangeCartCountServlet',
type:'post',
dataType:'text',
data:{
bookid:id,
count:parseInt($("#count"+id).val())+1
},
success:function(data){
if(data=="false"){
alert("库存不足!!!!");
}
else{
var price = $("#price"+id).html();
$("#count"+id).val(parseInt($("#count"+id).val())+1);
$("#sum"+id).val("￥"+price*$("#count"+id).val());
calcTotal();
}
}
});
}
function calcTotal(){
// input...
var counts = $("input[id^=count]").toArray();
var prices = $("div[id^=price]").toArray();
var total = 0;
for(var i=0;i<prices.length;i++){
total += prices[i].innerHTML*counts[i].value;
}
$("#total").val("￥"+total);
}
</script>
</head>
<body>
<div id="header" class="wrap">
<div id="banner"></div>
<div id="navbar">
<div class="userMenu">
<ul>
<li class="current"><font color="BLACK">欢迎您，<strong>andy</strong></font> </li>
<li><a href="index.jsp">首页</a></li>
<li><a href="orderlist.html">我的订单</a></li>
<li><a href="show_cart.jsp">购物车</a></li>
<li><a href="logout.jsp">注销</a></li>
</ul>
</div>
</div>
</div>
<div id="content" class="wrap">
<div class="list bookList">
<form method="post" name="shoping" action="">
<table>
<tr class="title">
<th class="view">图片预览</th>
<th>书名</th>
<th class="nums">数量</th>
<th class="price">价格</th>
<th class="nums">合计</th>
<th class="nums">操作</th>
</tr>
<c:set var="total" value="0"></c:set>
<c:forEach items="${cart}" var="book">
<tr>
<td class="thumb">
<img src="images/book/${book.value.image}" /></td>
<td class="title">${book.value.bookname}</td>
<td>
<img src="images/edit_jian.png" width="12" height="12"
onclick="jian(${book.value.bid})"/>
<input id="count${book.value.bid}" readonly="readonly"
value="${book.value.count}" size="2"/>
<img src="images/edit_add.png" width="12" height="12"
onclick="add(${book.value.bid})"/>
</td>
<td>￥
<div id="price${book.value.bid}" >${book.value.price}</div>
</td>
<td>
<input id="sum${book.value.bid}"
value='<fmt:formatNumber
value="${book.value.count*book.value.price}"
type="currency"></fmt:formatNumber>'
/>
<c:set var="total"
value=
"${total+book.value.count*book.value.price}"></c:set>
<input type="hidden" name="items" value="10:2:31.6"/>
</td>
<td>
<a href="DeleteCartItemServlet?bookid=${book.value.bid}">删除</a>
</td>
</tr>
</c:forEach>
<tr><td colspan="5">
<div class="button">
<h4>总价：
<input id="total"
value='<fmt:formatNumber value="${total}" type="currency"></fmt:formatNumber>'
/>
元</h4>
<input type="hidden" id="hidden_total_price" name="hidden_total_price"/>
<input class="input-chart" type="submit" name="submit" value="" />
</div>
</td></tr>
</table>
</form>
</div>
</div>
</body>
<div id="footer" class="wrap">
网上书城 © 版权所有
</div>
</html>
</html>
package com.news.util;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
//Dao工厂类
public class DaoFactory {
private static String driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
private static String url = "jdbc:sqlserver://localhost:1433;DatabaseName=News";
private static String user = "sa";
private static String pwd = "123@qwe";
// private static String driver="com.mysql.jdbc.Driver";
// private static String url="jdbc:mysql://localhost:3306/news";
// private static String user = "root" ;
// private static String pwd = "admin" ;
// 1.公共方法是获得数据库链接对象
public static Connection getConnection() {
Connection con = null;
try {
Class.forName(driver);// 加,连
con = DriverManager.getConnection(url, user, pwd);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return con;// 非void都需要return
}
// 2.关闭所有方法;有3个参数!,省代码了!!!
public static void closeAll(ResultSet rs, Statement stmt, Connection con) {
try {
if (rs != null) {
rs.close();
}
if (stmt != null) {
stmt.close();
}
if (con != null) {
con.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
// 3.setParams,用来设置预编译语句对象的?占位符的值;
public static void setParams(PreparedStatement pstmt, Object[] params) {
if (params == null) {
return;
}// return:直接返回，啥也不做;
try {
for (int i = 0; i < params.length; i++) {
pstmt.setObject(i + 1, params[i]);
}
} catch (SQLException e) {// 有异常,加上去
e.printStackTrace();
}
}
// 4.做公共的更新方法，可以更新所有的基本sql语句;
public int executeUpdate(String sql, Object[] params) {
// 1.声明对象;是将来工作当中省内存;
Connection con = null;
PreparedStatement pstmt = null;
int count = 0; // 增删改受影响的行数;
try {
con = this.getConnection();// 调用本类的方法；
pstmt = con.prepareStatement(sql);// 建对象:预编译对象,?
setParams(pstmt, params);// 调用设置?的方法，已经写过了!!!
count = pstmt.executeUpdate();// 3.执行;
} catch (SQLException e) {
e.printStackTrace();
} finally {
this.closeAll(null, pstmt, con);
}
return count;
}
// 5.执行查询方法;
public static List executeQuery(String sql, Object[] params) {
Connection con = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
int colCount = 0;
ArrayList tableList=new ArrayList();//表集合
try {
con = getConnection();
pstmt = con.prepareStatement(sql);
setParams(pstmt, params);
rs = pstmt.executeQuery();// 执行查询，结果给rs
ResultSetMetaData rd = rs.getMetaData();// 获得元数据
colCount = rd.getColumnCount();
while (rs.next()) {
ArrayList rowList = new ArrayList();//行集合
for (int i = 1; i <= colCount; i++) {
rowList.add(rs.getString(i));
}
tableList.add(rowList);
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
closeAll(rs,pstmt,con);
}
return tableList;
}
}
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