今天练习了一个登陆，然后能查看商品，查看购物车并且进行相关简单操作的小程序。 登陆的用户名为admin，密码为123 大致程序清单：
MySQL语句：
create database shopcar; ---------- use shopcar; ---------- create table goods( id int not null auto_increment primary key, gname varchar(25), price dec(10,2), total int, pic varchar(56) ); ---------- insert into goods(gname,price,total,pic) values('蓝色拖鞋',22.5,100,'ups/pic01.jpg'); insert into goods(gname,price,total,pic) values('黑色男士衬衫',85,500,'ups/pic02.jpg'); insert into goods(gname,price,total,pic) values('浴帽',18,65,'ups/pic03.jpg'); insert into goods(gname,price,total,pic) values('蓝牙耳机',200,90,'ups/pic04.jpg'); insert into goods(gname,price,total,pic) values('男童T-shit',40,1000,'ups/pic05.jpg'); ----------login.html
<!DOCTYPE html> <!--登录页面 主页 --> <html> <head> <meta charset="UTF-8"> <title>登录</title> </head> <body> <center> <form action="checkLogin" method="post"> 用户名:<input type="text" name="uname" required="required" pattern="\w{3,12}"/><br/><!-- required的意思是此空为必填项，pattern后面的是正则表达式 --> 密码：<input type="password" name="upwd" required/><br/> <button type="submit">登录</button> </form> </center> </body> </html>C3p0.properities
c3p0.driverClass=com.mysql.jdbc.Driver c3p0.user=root c3p0.password=mysql c3p0.jdbcUrl=jdbc:mysql://localhost:3306/shopcar c3p0.initialPoolSize=3 c3p0.maxPoolSize=10 c3p0.minPoolSize=2在com.shop.pojo下创立Goods.java
package com.shop.pojo; //商品类，包括商品的所有信息，设置get和set方法 import java.io.Serializable; import java.math.BigDecimal; public class Goods implements Serializable { private int id; private String gname; private BigDecimal price; private int total; private String pic; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getGname() { return gname; } public void setGname(String gname) { this.gname = gname; } public BigDecimal getPrice() { return price; } public void setPrice(BigDecimal price) { this.price = price; } public int getTotal() { return total; } public void setTotal(int total) { this.total = total; } public String getPic() { return pic; } public void setPic(String pic) { this.pic = pic; } }在com.shop.dao下建立GoodsDao.java
package com.shop.dao; //商品方法的接口，有得到所有商品、根据id获得商品对象的抽象方法。 import java.util.List; import com.shop.pojo.Goods; public interface GoodsDao { public List<Goods> getAll(); public Goods getById(int id); }在com.shop.dao下建立GoodsDaoImp.java
package com.shop.dao; //商品方法的实现类，有得到所有商品、根据id获得商品对象的方法。 import java.sql.SQLException; import java.util.List; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.BeanHandler; import org.apache.commons.dbutils.handlers.BeanListHandler; import com.mchange.v2.c3p0.ComboPooledDataSource; import com.shop.pojo.Goods; public class GoodsDaoImp implements GoodsDao { private static ComboPooledDataSource ds=new ComboPooledDataSource(); private QueryRunner run=new QueryRunner(ds); @Override public List<Goods> getAll() { String sql="select * from goods"; List<Goods> list=null; try { list=run.query(sql, new BeanListHandler<Goods>(Goods.class));//new了一个BeanListHandler对象。可以将查询到的Goods的信息存到list中 } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return list; } @Override public Goods getById(int id) { String sql="select * from goods where id=?"; Goods list=null; try { list=run.query(sql, new BeanHandler<Goods>(Goods.class),id); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return list; } }在com.shop.servlet下建立CheckLoginServlet.java
package com.shop.servlet; //检查登录是否成功的Servlet，登录成功后跳转到ShowGoodsServlet，失败则跳转到login.html import java.io.IOException; import java.util.List; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import com.shop.dao.GoodsDaoImp; import com.shop.pojo.Goods; @WebServlet("/checkLogin") public class CheckLoginServlet extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setContentType("text/html;charset=utf-8"); req.setCharacterEncoding("utf-8"); HttpSession session=req.getSession(); String uname=null!=req.getParameter("uname")?req.getParameter("uname"):""; String upwd=null!=req.getParameter("upwd")?req.getParameter("upwd"):""; if("admin".equals(uname)&&"123".equals(upwd)) { session.setAttribute("loged", uname);//设置一个session Cookie cookie=new Cookie("uname",uname);//新建一个cookie对象 cookie.setMaxAge(60*60*60*60);//cookie的生命周期 resp.addCookie(cookie);//向resp中加入一个cookie req.getRequestDispatcher("showgoods").forward(req, resp);//向showgoods页面forward req 和 resp。 }else { resp.sendRedirect("login.html");//返回登录页面 } } }在com.shop.servlet下建立ShowGoodsServlet.java
package com.shop.servlet; //输出商品页面的Servlet，显示商品信息 import java.io.IOException; import java.io.PrintWriter; import java.util.List; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import com.shop.dao.GoodsDao; import com.shop.dao.GoodsDaoImp; import com.shop.pojo.Goods; @WebServlet("/showgoods") public class ShowGoodsServlet extends HttpServlet { private GoodsDao gd=new GoodsDaoImp(); @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setContentType("text/html;charset=utf-8");//箱客户端返回数据是text/html类型，编码是utf-8。 req.setCharacterEncoding("utf-8");//读取req的时候用utf-8,避免乱码 PrintWriter out=resp.getWriter();//输出流，文字输出流 HttpSession session=req.getSession();//得到checkloginservlet传过来的session String uname=(String)session.getAttribute("loged");//将session中的loged写入到uname字符串中，如果没有通过登录页面输入用户名的话，loged中将不会有信息，uname也为空 if(null==uname)//判断uname是否为空 { //说明你没有通过验证 resp.sendRedirect("login.html"); }else {//通过验证 List<Goods> list=gd.getAll(); out.println("<!DOCTYPE html>"); out.println("<html>"); out.println("<head>"); out.println(" <meta charset='UTF-8'>"); out.println(" <title>商品列表</title>"); out.println(" <style type='text/css'>"); out.println(" *{ padding: 0;margin: 0;}"); out.println(" #container{width: 800px; height: 600px; border: 1px #ccc solid; margin: 0 auto;}"); out.println(" #container header{ height: 80px; border-bottom: 2px #ccc solid;}"); out.println(" #container header h1{ width: 600px; float: left; font-family: '微软雅黑'; line-height: 50px;}"); out.println(" #container header p{ width: 200px; float: right; line-height: 50px;}"); out.println(" #container article{ clear: both; padding: 10px;}"); out.println(" #container article section{ display: inline-block; margin-bottom: 10px; margin-right: 10px;}"); out.println(" #container article section label{ width: 130px; display: block;}"); out.println("</style>"); out.println("</head>"); out.println("<body>"); out.println(" <div id='container'>"); out.println(" <header>"); out.println(" <h1>商品列表</h1>"); out.println(" <p>"); out.println(" <a href='shopcar'>查看购物车</a> "); out.println(" <a href='logout'>退出</a>"); out.println(" </p>"); out.println(" </header>"); out.println(" <article>"); if(null!=list) { for(Goods goods:list)//迭代list中的每一个goods对象 { out.println(" <section>"); out.println(" <img src='"+goods.getPic()+"' width='150' height='150' />");//商品图片 out.println(" <form action='addCar' method='post'>"); out.println("<input type='hidden' name='gid' value='"+goods.getId()+"'/>");//商品id out.println(" <label>"+goods.getGname()+"</label>");//商品名 out.println(" "+goods.getPrice()+" <select name='total'>");//商品价格，数量 for(int i=1;i<10;i++)// out.println(" <option value='"+i+"'>"+i+"</option>"); out.println(" </select>"); out.println(" <button type='submit'>购买</button>"); out.println(" </form>"); out.println(" "); out.println(" </section>"); } } out.println(" "); out.println(" </article>"); out.println(" </div>"); out.println("</body>"); out.println("</html>"); } out.close(); } }在com.shop.servlet下建立AddCarsServlet.java
package com.shop.servlet; //加入购物车这个行为的Servlet，成功的时候有提示 import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import java.util.List; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import com.shop.dao.GoodsDao; import com.shop.dao.GoodsDaoImp; import com.shop.pojo.Goods; @WebServlet("/addCar") public class AddCarServlet extends HttpServlet { private GoodsDao gd=new GoodsDaoImp(); @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setContentType("text/html;charset=utf-8"); req.setCharacterEncoding("utf-8"); PrintWriter out=resp.getWriter(); String gid=null!=req.getParameter("gid")?req.getParameter("gid"):"";//得到商品id HttpSession session=req.getSession(); if(gid.matches("\\d+")) { int id=Integer.parseInt(gid); Goods goods=gd.getById(id); goods.setTotal(Integer.parseInt(req.getParameter("total"))); List<Goods> shopcar=(List<Goods>)session.getAttribute("shopcar"); if(null==shopcar)shopcar=new ArrayList<Goods>(); shopcar.add(goods); session.setAttribute("shopcar", shopcar); out.println("<script>alert(\"加入成功!\");window.location='showgoods'</script>");//提示加入成功后跳转到ShowGoodsServlet }else { out.println("<script>window.location='showgoods'</script>");//失败则没有提示 } //resp.sendRedirect("showgoods"); out.close(); } }在com.shop.servlet下建立CarListServlet.java
package com.shop.servlet; //购物车显示页面 import java.io.IOException; import java.io.PrintWriter; import java.math.BigDecimal; import java.util.List; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import com.shop.pojo.Goods; @WebServlet("/shopcar") public class CarListServlet extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setContentType("text/html;charset=utf-8"); req.setCharacterEncoding("utf-8"); PrintWriter out=resp.getWriter(); out.println("<h1>购物车，您选择的商品如下:</h1>"); HttpSession session=req.getSession(); List<Goods> list=(List<Goods>)session.getAttribute("shopcar"); if(null!=list) { int index=1; for(int i=0;i<list.size();i++) { Goods goods=list.get(i); out.println("<ul>"); out.println("<li>"+(index++)//商品列表的数字（购物车中的第几个商品） + "<img src='"+goods.getPic()+"' width='150' height='150' />"); out.println("<label>"+goods.getGname()+"</label>"); out.println(goods.getPrice()+" "+goods.getTotal()+"个"+(goods.getPrice().multiply(new BigDecimal(String.valueOf(goods.getTotal()))))); //得到商品的单价，数量，总价 out.println(" <a href='deleteCar?index="+i+"'>删除</a> </li> "); out.println("</ul>"); out.println("<center><a href='showgoods'>返回</a></center>"); } }else{ out.println("您的购物车为空"); } out.close(); } }在com.shop.servlet下建立DeleteCarServlet.java
package com.shop.servlet; //删除购物车中的物品（行为） import java.io.IOException; import java.util.List; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import com.shop.pojo.Goods; @WebServlet("/deleteCar") public class DeleteCarServlet extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { HttpSession session=req.getSession(); List<Goods> list=(List<Goods>)session.getAttribute("shopcar"); if(null!=list) { list.remove(Integer.parseInt(req.getParameter("index")));//得到index对应的商品 } resp.sendRedirect("shopcar"); } }在com.shop.servlet下建立LogoutServlet.java
package com.shop.servlet; //登出行为 import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @WebServlet("/logout") public class LogoutServlet extends HttpServlet { @Override protected void service(HttpServletRequest arg0, HttpServletResponse arg1) throws ServletException, IOException { arg0.getSession().invalidate();//删除会话 arg1.sendRedirect("showgoods"); } }初学者，如果发现有错误，请多指正~
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