标签：java 数据库 servlet 设计 javaweb
做课程设计的时候 做的有点烦了 所以就简单的写了点 以下就是将添加到购物车的商品动态的显示到前台页面的代码
首先是我的head.jsp这里面的“我的目录“使用的不是直接链接而是一个servlet名称叫做”selectUserCart“
我的里面使用的user、books、userAccout类都是基本的记录了基本信息的类为其实现setXxx（）和getXxx（）方法
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link rel="stylesheet" type="text/css" href="style.css" />
</head>
<body >
<div id="wrap" >
<%
if(session.getAttribute("username") == null) {
%>
<br/>你还没有登录请<a href="login.jsp">登陆</a>/<a href="register.jsp">注册</a>以查看或购买
<%
}else{
%>
<br/>您好！<%=session.getAttribute("username") %>
<%
}
%>
<div class="header">
<!-- <br/>你还没有登录请<a href="login.jsp">登陆</a>/<a href="register.jsp">注册</a>以查看或购买 -->
<div class="logo"><a href="index.htm"><img src="images/logo.gif" alt="" title="" border="0" /></a></div>
<div id="menu">
<ul>
<li class="selected"><a href="index.jsp">主页</a></li>
<li><a href="about.jsp">关于我们</a></li>
<li><a href="category">图书</a></li>
<li><a href="specials.jsp">特别推荐</a></li>
<li><a href="selectUserCart">我的目录</a></li>
<li><a href="register.jsp">注册</a></li>
<li><a href="contact.jsp">购买</a></li>
</ul>
</div>
</div>
</div>
</body>
</html>
然后是我使用到的两个类：
搜索我的购物车的工具类：myCartUtil.java
<pre name="code" class="java">package myCart;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import bookConnUtil.DBUtil;
import bookConnUtil.books;
public class myCartUtil {
public static ArrayList<mycart> list = new ArrayList<mycart>();
public static ArrayList<books> booklist = new ArrayList<books>();
public static String msg;
public static int countbook = 0;
//public static mycart[] cart = new mycart[10];
public static int count = 0;
public static boolean insertIntoMyCart(String username,String bookname,String pianduanName) throws SQLException{
String cartInsert = "insert into userAccount valus(?,?,?)";
boolean flag = false;
Connection conn=null;
PreparedStatement stmt=null;
try{
conn = DBUtil.getConnection(DBUtil.CONNECTION_SQL);
stmt = conn.prepareStatement(cartInsert);
stmt.setString(1, username);
stmt.setString(2, bookname);
stmt.setString(3, pianduanName);
int count = stmt.executeUpdate();
if(count>0){
flag=true;
}else{
flag=false;
}
}catch(Exception e){
System.out.println("真心对不住，您的程序出错了");
e.printStackTrace();
}finally{
conn.close();
stmt.close();
}
return flag;
}
public static boolean selectUserCart(String userName) throws SQLException{
boolean flag = false;
String cartSelect = "select username,bookname,pianduanName,imagePath,price from userAccount where username =?";
Connection conn=null;
ResultSet rs=null;
PreparedStatement stmt=null;
try{
conn = DBUtil.getConnection(DBUtil.CONNECTION_SQL);
stmt = conn.prepareStatement(cartSelect);
stmt.setString(1, userName);
rs = stmt.executeQuery();
while(rs.next()){
mycart cart = new mycart();
cart.setUserName(rs.getString(1));
cart.setBookName(rs.getString(2));
cart.setPianduanName(rs.getString(3));
cart.setImagePath(rs.getString(4));
cart.setPrice(rs.getInt(5));
list.add(cart);
count++;
}
System.out.println("++++++++++++++++"+count+"+++++++++++++");
if(count==0){
msg = "null";
}else{
msg = "full";
}
flag = true;
}catch(Exception e){
System.out.println("真心对不起，你的程序出错了");
e.printStackTrace();
}finally{
conn.close();
stmt.close();
}
return flag ;
}
public static boolean selectAllBooks() throws SQLException{
boolean flag = false;
String cartSelect = "select bookId,bookName,pianduanName,imagesPath,price from books";
Connection conn=null;
ResultSet rs=null;
PreparedStatement stmt=null;
try{
conn = DBUtil.getConnection(DBUtil.CONNECTION_SQL);
stmt = conn.prepareStatement(cartSelect);
rs = stmt.executeQuery();
while(rs.next()){
books book = new books();
book.setBookID(rs.getString(1));
book.setBookName(rs.getString(2));
book.setPianduanName(rs.getString(3));
book.setImagePath(rs.getString(4));
book.setPrice(rs.getInt(5));
booklist.add(book);<span style="white-space:pre"> </span>//我没怎么好好做所以就用这个标记的 想要做的更好点请自行实现
countbook++;
}
System.out.println("++++++++++++++++"+count+"+++++++++++++");
if(count==0){
msg = "null";
}else{
msg = "full";
}
flag = true;
}catch(Exception e){
System.out.println("真心对不起，你的程序出错了");
e.printStackTrace();
}finally{
conn.close();
stmt.close();
}
return flag ;
}
}
<pre name="code" class="java">package bookConnUtil;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class DBUtil {
public static final int CONNECTION_MYSQL=2;
public static final int CONNECTION_SQL=1;
public static final int CONNECTION_ODBC=0;
public DBUtil() { }
public static Connection getConnection(int connection_type)throws Exception
{
switch (connection_type)
{
case CONNECTION_ODBC:
return getConnectionODBC();
case CONNECTION_SQL:
return getConnectionSQL();
case CONNECTION_MYSQL:
return getConnectionMYSQL();
}
return null;
}
/**
* ??????????
*/
private static Connection getConnectionODBC()throws Exception
{
Connection conn=null;
try
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
System.out.println("abc");
conn=DriverManager.getConnection("jdbc:odbc:mybook","sa","123");
System.out.println("连接成功");
}
catch(Exception e)
{
e.printStackTrace();
throw e;
}
return conn;
}
private static Connection getConnectionSQL() throws Exception
{
Connection conn=null;
String connectionUrl = "jdbc:sqlserver://localhost:1433;databaseName=user;";
try
{
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
conn=DriverManager.getConnection(connectionUrl,"sa","123");
System.out.println("连接成功");
}
catch(Exception e)
{
e.printStackTrace();
throw e;
}
return conn;
}
private static Connection getConnectionMYSQL() throws Exception
{
String connectionUrl = "jdbc:mysql://localhost:3306/user";
String username = "root";
String password = "mysql";
Connection conn=null;
try
{
Class.forName("com.mysql.jdbc.Driver");
conn=DriverManager.getConnection(connectionUrl, username,password);
System.out.println("连接成功");
}
catch(Exception e)
{
e.printStackTrace();
throw e;
}
return conn;
}
public static void close(Connection conn) throws Exception
{
if(conn!=null)
{
try
{
conn.close();
}
catch(SQLException e)
{
e.printStackTrace();
throw e;
}
}
}
}
<pre name="code" class="java">package myCart;
import java.io.IOException;
import java.sql.SQLException;
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 bookConnUtil.bookDAO;
public class selectUserCart extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
public int count = myCartUtil.count;
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
HttpSession session=req.getSession();
String username =(String) session.getAttribute("username");
try {
//System.out.println("还没执行到查询过程这里");
boolean flag=myCartUtil.selectUserCart(username);
if(flag==true){
/*for(mycart message:myCartUtil.list){
for(int i=0;i<3;i++){
String A = message.getUserName();
}
}*/
//session.setAttribute("count",countNum);
if(myCartUtil.msg.equals("null")){
session.setAttribute("null", myCartUtil.msg);
}else{
session.setAttribute("full", myCartUtil.msg);
}
req.getRequestDispatcher("selectMyAcccount.jsp").forward(req, resp);
}else{
req.getRequestDispatcher("error.html").forward(req, resp);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
<pre name="code" class="html"><%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Book Store</title>
<link rel="stylesheet" type="text/css" href="style.css" />
</head>
<body onload="selectUserCart">
<jsp:include page="head.jsp"/>
<div id="wrap">
<div class="center_content">
<div class="left_content">
<%
if(session.getAttribute("username") == null) {
%>
<script type="text/javascript" language="javascript">
alert("您还没有登录，请登录...");
window.document.location.href="login.jsp";
</script>
<%
}
%>
<div class="title"><span class="title_icon"><img src="images/bullet1.gif" alt="" title="" /></span>My account</div>
<div class="feat_prod_box_details">
<p class="details"> 我还没有什么时间进行修改，所以使用的是以前的版本这样的话造成的不便请您谅解。所有权为作者所有我还没有什么时间进行修改，所以使用的是以前的版本这样的话造成的不便请您谅解。所有权为作者所有我还没有什么时间进行修改，所以使用的是以前的版本这样的话造成的不便请您谅解。所有权为作者所有我还没有什么时间进行修改，所以使用的是以前的版本这样的话造成的不便请您谅解。所有权为作者所有 </p>
<div class="contact_form">
<div class="form_subtitle">登陆 以查看清单</div>
<form name="register" method="post" action="UserDAO">
<div class="form_row">
<label class="contact"><strong>用户名:</strong></label>
<input type="text" class="contact_input" name="userName" />
</div>
<div class="form_row">
<label class="contact"><strong>密 码:</strong></label>
<input type="password" class="con tact_input" name="password" />
</div>
<div class="form_row">
<div class="terms">
<input type="checkbox" name="terms" />
记住密码 </div>
</div>
<div class="form_row">
<input type="submit" class="register" value="登陆" />
</div>
</form>
</div>
<div class="contact_form">
<div class="form_subtitle">更新书籍信息</div>
<form name="updateBookMsg" method="post" action="updateBookMsg">
<div class="form_row">
<label class="contact"><strong>图 书ID:</strong></label>
<input type="text" class="contact_input" name="bookId" />
</div>
<div class="form_row">
<label class="contact"><strong>图 书 名:</strong></label>
<input type="text" class="contact_input" name="bookName" />
</div>
<div class="form_row">
<label class="contact"><strong>图书简介:</strong></label>
<input type="text" class="contact_input" name="pianduanName" />
</div>
<div class="form_row">
<input type="submit" class="register" value="提交" />
</div>
</form>
</div>
</div>
<div class="clear"></div>
</div>
<jsp:include page="broadside.jsp"/>
</div>
</div>
</body>
</html>
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标签：java 数据库 servlet 设计 javaweb
原文地址：http://blog.csdn.net/bluezhangfun/article/details/46761383
