JavaWeb购物车项目开发实战指南

网友投稿 342 2022-07-23


目录一、项目前提二、数据库的创建三、eclipse进行创建包和类:四、主要实现功能1、购物车用户登录2、商品显示3、购物车添加&商品总数和价格的计算总结

一、项目前提

1、购物车并不是一直放数据库

2、选择使用的技术:

session:(购物车项目使用session)好处:快(放在内存当中),存对象的坏处:占用内存,服务器意外待机数据会丢失cookie好处:不占用内存,存储很久坏处:存在客户端上,只能存String,数据有泄露的风险

二、数据库的创建

用户表

create table shop_user (

id number primary key,--用户id

account varchar2(30) not null,--用户账户

password varchar2(30)not null--用户密码

);

商品表

create table shop_goods(

id number primary key,--商品id

name varchar2(50) not null,--商品名称

price number default 0.0,--商品价格

info varchar2(255) default '三五产品' not null--商品介绍

);

三、eclipse进行创建包和类:

com.zking.util    帮助类com.zking.pojo  实体类com.zking.dao(放dao接口)com.zking.dao.imp    (放dao接口实现类)com.zking.biz (业务逻辑层放dao方法)com.zking.biz.imp(业务逻辑层放dao实现类) com.zking.vo (view object 视图对象 前端用)

四、主要实现功能

1、购物车用户登录

login.jsp

界面效果

代码如下:

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

doLogin.jsp(处理登录界面)

<%@page import="com.zking.vo.CarItem"%>

<%@page import="java.util.ArrayList"%>

<%@page import="java.util.List"%>

<%@page import="com.zking.pojo.User"%>

<%@page import="com.zking.biz.impl.UserBizImpl"%>

<%@page import="com.zking.biz.IUserBiz"%>

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%

request.setCharacterEncoding("UTF-8");

String account=request.getParameter("account");

String password=request.getParameter("password");

IUserBiz userBiz=new UserBizImpl();

User user=userBiz.login(new User(0,account,password));

if(user==null){

response.sendRedirect("login.jsp");

}else{

//首页需要登录数据

session.setAttribute("user",user);

//分配购物车

Listcar=new ArrayList<>();

//放到session中(把购物车给我)

session.setAttribute("car", car);

response.sendRedirect("index.jsp");

}

%>

用户实体类User.java

package com.zking.pojo;

public class User {

private Integer id;

private String account;

private String password;

public Integer getId() {

return id;

}

public void setId(Integer id) {

this.id = id;

}

public String getAccount() {

return account;

}

public void setAccount(String account) {

this.account = account;

}

public String getPassword() {

return password;

}

public void setPassword(String password) {

this.password = password;

}

public User(Integer id, String account, String password) {

super();

this.id = id;

this.account = account;

this.password = password;

}

public User() {

super();

}

@Override

public String toString() {

return "User [id=" + id + ", account=" + account + ", password=" + password + "]";

}

}

IUserBiz.java (用户逻辑接口)

package com.zking.biz;

import com.zking.pojo.User;

/**

* 用户逻辑接口

* @author zjjt

*

*/

public interface IUserBiz {

User login(User user);

}

UserBizImpl.java (用户逻辑接口实现类)

package com.zking.biz.impl;

import com.zking.biz.IUserBiz;

import com.zking.dao.IUserDao;

import com.zking.dao.impl.UserDaoImpl;

import com.zking.pojo.User;

/**

* 用户逻辑接口实现类

* @author zjjt

*

*/

public class UserBizImpl implements IUserBiz{

private IUserDao userDao=new UserDaoImpl();

@Override

public User login(User user) {

User u = userDao.login(user);

if(u!=null) {

if(u.getPassword().equals(user.getPassword())) {

return u;

}

}

return null;

}

}

IUserDao.java(用户数据访问接口)

package com.zking.dao;

import com.zking.pojo.User;

/**

* 用户数据访问接口

* @author zjjt

*

*/

public interface IUserDao {

User login(User user);

}

UserDaoImpl.java(用户数据访问接口实现类)

package com.zking.dao.impl;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.util.List;

import com.zking.dao.IUserDao;

import com.zking.pojo.User;

import com.zking.util.DBHelper;

public class UserDaoImpl implements IUserDao {

private Connection con;

private PreparedStatement ps;

private ResultSet rs;

@Override

public User login(User user) {

try {

con=DBHelper.getCon();

ps=con.prepareStatement("select * from shop_user where account=?");

ps.setString(1,user.getAccount());

rs=ps.executeQuery();

if(rs.next()) {

User u=new User();

u.setId(rs.getInt(1));

u.setAccount(rs.getString(2));

u.setPassword(rs.getString(3));

return u;

}

} catch (Exception e) {

e.printStackTrace();

}finally {

DBHelper.close(con, ps, rs);

}

return null;

}

}

2、商品显示

实现效果如下:

将数据库存放的数据显示在页面上,尊贵的xxx通过session拿到登录的用户名

Goods.java(商品实体类)

package com.zking.pojo;

public class Goods {

private Integer id;

private String name;

private Integer price;

private String info;

public Integer getId() {

return id;

}

public void setId(Integer id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public Integer getPrice() {

return price;

}

public void setPrice(Integer price) {

this.price = price;

}

public String getInfo() {

return info;

}

public void setInfo(String info) {

this.info = info;

}

public Goods(Integer id, String name, Integer price, String info) {

super();

this.id = id;

this.name = name;

this.price = price;

this.info = info;

}

public Goods() {

super();

}

@Override

public String toString() {

return "Goods [id=" + id + ", name=" + name + ", price=" + price + ", info=" + info + "]";

}

}

index.jsp(首页代码)

<%@page import="com.zking.pojo.Goods"%>

<%@page import="com.zking.biz.impl.GoodsBizImpl"%>

<%@page import="com.zking.biz.IGoodsBiz"%>

<%@page import="com.zking.pojo.User"%>

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%

Object obj=session.getAttribute("user");

if(obj==null){

response.sendRedirect("login.jsp");

return;

}

%>

尊贵的<%=((User)obj).getAccount() %>

<%=session.getAttribute("car")%>

<%

IGoodsBiz goodsBiz=new GoodsBizImpl();

for(Goods goods:goodsBiz.getAll()){

%>

添加购物车

<%

}

%>

IGoodsBiz.java (商品逻辑接口)

package com.zking.biz;

import java.util.List;

import com.zking.pojo.Goods;

/**

* 商品逻辑接口

* @author zjjt

*

*/

public interface IGoodsBiz {

ListgetAll();

//查询单个

Goods getOne(Integer id);

}

GoodsBizImpl.java (商品逻辑接口实现类)

package com.zking.biz.impl;

import java.util.List;

import com.zking.biz.IGoodsBiz;

import com.zking.dao.IGoodsDao;

import com.zking.dao.impl.GoodsDaoImpl;

import com.zking.pojo.Goods;

/**

* 商品逻辑接口实现类

* @author zjjt

*

*/

public class GoodsBizImpl implements IGoodsBiz {

private IGoodsDao goodsDao=new GoodsDaoImpl();

@Override

public List getAll() {

return goodsDao.getAll();

}

@Override

public Goods getOne(Integer id) {

return goodsDao.getOne(id);

}

}

IGoodsDao.java (商品数据访问接口)

package com.zking.dao;

import java.util.List;

import com.zking.pojo.Goods;

/**

* 商品数据访问接口

* @author zjjt

*

*/

public interface IGoodsDao {

//查询所有

ListgetAll();

//查询单个

Goods getOne(Integer id);

}

GoodsDaoImpl.java (商品数据访问接口实现类)

package com.zking.dao.impl;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.util.ArrayList;

import java.util.List;

import com.zking.dao.IGoodsDao;

import com.zking.pojo.Goods;

import com.zking.pojo.User;

import com.zking.util.DBHelper;

/**

* 访问数据接口实现类

* @author zjjt

*

*/

public class GoodsDaoImpl implements IGoodsDao{

private Connection con;

private PreparedStatement ps;

private ResultSet rs;

/**

* 查询全部商品

*/

@Override

public List getAll() {

Listlist=new ArrayList();

try {

con=DBHelper.getCon();

ps=con.prepareStatement("select * from shop_goods ");

rs=ps.executeQuery();

while(rs.next()) {

Goods goods=new Goods();

goods.setId(rs.getInt(1));

goods.setName(rs.getString(2));

goods.setPrice(rs.getInt(3));

goods.setInfo(rs.getString(4));

list.add(goods);

}

return list;

} catch (Exception e) {

e.printStackTrace();

}finally {

DBHelper.close(con, ps, rs);

}

return list;

}

/**

* 根据id查询商品

*/

@Override

public Goods getOne(Integer id) {

try {

con=DBHelper.getCon();

ps=con.prepareStatement("select * from shop_goods where id=? ");

ps.setInt(1, id);

rs=ps.executeQuery();

if(rs.next()) {

Goods goods=new Goods();

goods.setId(rs.getInt(1));

goods.setName(rs.getString(2));

goods.setPrice(rs.getInt(3));

goods.setInfo(rs.getString(4));

return goods;

}

} catch (Exception e) {

e.printStackTrace();

}finally {

DBHelper.close(con, ps, rs);

}

return null;

}

}

3、购物车添加&商品总数和价格的计算

doAddCar.java(处理添加购物车的页面)

<%@page import="java.util.List"%>

<%@page import="com.zking.biz.impl.GoodsBizImpl"%>

<%@page import="com.zking.biz.IGoodsBiz"%>

<%@page import="com.zking.vo.CarItem"%>

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<%

//添加购物车的页面

//拿购物车

Listcar=(List)session.getAttribute("car");

IGoodsBiz goodsBiz=new GoodsBizImpl();

//1、得知道是那件商品

String str=request.getParameter("id");

int id=-1;

if(str!=null){

id=Integer.parseInt(str);

}

//2-1 判断该商品是否存在

boolean f=true;

for(CarItehttp://m item:car){

//item.getGoods().getId() 条目的商品id

if(id==item.getGoods().getId()){

//商品应该是已经被添加了[购物车中某个条目的商品id和你需要添加的商品id相同了]

item.setCount(item.getCount()+1);//数量+1

item.setSum(item.getCount()*item.getGoods().getPrice());

f=false;

break;

}

}

//只要判断f是否发生了改变

if(f){

//2-2、生成一个CarItem[如果购物车没有该商品]

CarItem carItem=new CarItem();

//设置对应的商品数据

carItem.setGoods(goodsBiz.getOne(id));

//数量

carItem.setCount(1);

//加车数量*商品单价

//carItem.getCount()商品加车的数量

//carItem.getGoods().getPrice() 商品的单价

carItem.setSum(carItem.getCount()*carItem.getGoods().getPrice());

//将购物条目carItem 绑定到购物车

car.add(carItem);

}

//更新购物车

session.setAttribute("car", car);

//跳回首页

response.sendRedirect("index.jsp");

%>

CarItem.java(购物车中的每一项,每一个条目)

package com.zking.vo;

import com.zking.pojo.Goods;

/**

* 购物车中的每一项,每一个条目

* @author zjjt

*

*/

public class CarItem {

private Integer count;//数量

private Integer sum;//条目总价

private Goods goods;//对应的商品

public Integer getCount() {

return count;

}

public void setCount(Integer count) {

this.count = count;

}

public Integer getSum() {

return sum;

}

public void setSum(Integer sum) {

this.sum = sum;

}

public Goods getGoods() {

return goods;

}

public void setGoods(Goods goods) {

this.goods = goods;

}

public CarItem(Integer count, Integer sum, Goods goods) {

super();

this.count = count;

this.sum = sum;

this.goods = goods;

}

public CarItem() {

// TODO Auto-generated constructor stub

}

@Override

public String toString() {

return "CarItem [count=" + count + ", sum=" + sum + ", goods=" + goods + "]";

}

}

效果先简单打印到页面 之后会进行修改

今天的分享就到这里结束啦!!

以上就是关于JavaWeb购物车项目的一些内容!!

总结


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