一个简单的java web 项目

Posted 2020-09-03 千牛一刀

tags:

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本文实现一个简单的 java web 项目，包括以下5个功能：

1. 登录

用户默认主页index.jsp , 可选择登录功能，输入用户名和密码，若登录成功，则进入产品管理总页面main.jsp。若不成功仍退回index.jsp

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2. 注册

用户默认主页index.jsp , 可选择注册功能，若注册，则进入 register.jsp

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3. 管理产品(增加，删除，查看)

登录成功后，进入产品管理总页面main.jsp。第一次进入main.jsp，默认显示所有产品列表。在此页面上更实现查询某个产品记录，添加产品，批量删除，选中一项产品查看详情，实现分页功能。

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3.1 添加产品

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3.2 查询"圣女果"

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3.3 选择“香蕉” ，点击 “查看”

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4. 退出

用户点击“退出”时，清除session，退回主页面index.jsp

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5. 过滤器

若用户没有登录成功，而直接访问 main.jsp 或 addProduct.jsp ,则被过滤器过滤到 index.jsp . 因为有成功登录，验证其身份后，才有权利访问产品和管理产品。否则将被过滤到默认主页index.jsp.

例如：在地址栏直接输入:http://192.168.0.103:8080/xianfengProject/main.jsp,则被过滤到index.jsp

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-------------------------------------------------------------------------------

项目环境：

操作系统：win7

实现技术：jsp+servlet

数据库: mysql5.5.20 , Navicat_for_MySQL_11.0.10

服务器：apache-tomcat-7.0.40

开发平台： MyEclipse10

--------------------------------------------------------------------------------

说明：

1. 数据库

数据库名:mydb , 共两张表.

表一：userinfo (id , username , pswd)

表二：product (proid , proname, proprice , proaddress , proimage)

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product (proid , proname, proprice , proaddress , proimage)表结构：

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userinfo (id , username , pswd)表结构如下：

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2. MyEclipse 工程目录

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----------------------------------------------------------------------------------------------------------------------

1. index.jsp

<%@ 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%>">
	
	
	<title>先锋管理系统欢迎您</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" type="text/css" href="styles.css">
	-->
		
<script type="text/javascript">
function login(){
	var th = document.form1;
	if(th.username.value==""){
		alert("用户名不能为空！");
		th.username.focus();
		return;
	}
	if(th.pswd.value==""){
		alert("密码不能为空！");
		th.pswd.focus();
		return;
	}
	
	th.action = "<%=path%>/servlet/LoginAction";
	th.submit();


}

</script>
	
  </head>
  
  <body>
  
   <div style="text-align:center">   
   <form name="form1" action="" method="post">
   <table  style="margin:auto">   
   <tr>   		
   		<td colspan="2">
   		先锋管理系统欢迎你！
   		</td>   		
   	</tr>
   	<tr>
   		<td>用户名：</td>
   		<td><input type="text" name="username"></input></td>   		
   	</tr>
   	<tr>
   		<td>密	码：</td>
   		<td><input type="password" name="pswd"></input></td>   		
   	</tr>
   		<tr>
   		
   		<td colspan="2" align="center">
   		<button type="button" name="" value="" onclick="login()">登录</button>
   		<button type="button" name="" value="" onclick="javascript:location.href=‘register.jsp‘">注册</button>
   		</td>   		
   	</tr>   
   
   </table>
   </form>
  </div>
 
   
  </body>
</html>

2. register.jsp

<%@ 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%>">
    
    <title>注册新用户</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" type="text/css" href="styles.css">
	-->
<script type="text/javascript">
function dosubmit(){
	
	var th = document.form1;
	if(th.username.value==""){
		alert("用户名不能为空！");
		th.username.focus();
		return;
	}
	if(th.pswd.value==""){
		alert("密码不能为空！");
		th.pswd.focus();
		return;
	}
	th.action="<%=path%>/servlet/RegisterAction";
	th.submit();

}
function back(){
 	alert("退回主页！");
	th = document.form1;
	th.acton="<%=path%>/index.jsp";
	th.submit;
}

</script>

  </head>
  
  <body>
    <div style="text-align:center">   
   <form action="" name="form1" method="post">
   <table  style="margin:auto">   
   <tr>   		
   		<td colspan="3">
   		用户注册
   		</td>   		
   	</tr>
   	<tr>
   		<td>用户名：</td>
   		<td><input type="text" name="username"></input></td>  
   		<td>必须填写！</td> 		
   	</tr>
   	<tr>
   		<td>密    码：</td>
   		<td><input type="password" name="pswd"></input></td>  
   		<td>必须填写！</td>  		
   		
   	</tr>
   	<tr>
   		
   		<td colspan="3" align="center">
   		<button type="button" name="" onclick="dosubmit()" >确定</button>
   		<button type="button" name="" value="" onclick="javascript:location.href=‘index.jsp‘" >返回</button>
   		</td>   		
   	</tr>   
   
   </table>
   </form>
  
  </div>
 
  </body>
</html>

3.main.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="com.util.*" %>
<%@ page import="com.product.*" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
//获取 session 中的 username;
String username = (String)session.getAttribute("username");
//获取从 servlet ProductActiion 中 传递的参数(数据库查询的结果)
List<Map<String,Object>> list =(List<Map<String,Object>>) request.getAttribute("listProduct");
// 获取 分页对象
DividePage dividePage = (DividePage) request.getAttribute("dividePage");
// 获取查询的关键词
String productName = (String) request.getAttribute("productName");
if(list==null){
	//第一次进 main.jsp页面，默认加载所有的产品
	ProductService service = new ProductDao();
	int totalRecord = service.getItemCount("");
	dividePage = new DividePage(5,totalRecord,1);
	int start = dividePage.fromIndex();
	int end = dividePage.toIndex();
	list = service.listProduct("", start, end);
}
	
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>产品管理</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" type="text/css" href="styles.css">
	-->
	<script type="text/javascript">
	function searchProduct(){
		var th = document.form2;
		th.action="<%=path%>/servlet/ProductAction?action_flag=search";
		th.submit();
	}
	
	function first(){
		
		window.location.href = "<%=path%>/servlet/ProductAction?action_flag=search&pageNum=1";
		
	}
	function next(){
		
		window.location.href = "<%=path%>/servlet/ProductAction?action_flag=search&pageNum=<%=dividePage.getCurrentPage()+1%>";		
	
	}
	function forward(){
		
		window.location.href = "<%=path%>/servlet/ProductAction?action_flag=search&pageNum=<%=dividePage.getCurrentPage()-1%>";
		
	}
	function end(){
		
		window.location.href = "<%=path%>/servlet/ProductAction?action_flag=search&pageNum=<%=dividePage.getPageCount() %>";
			
	}
	
	function changePage(currentPage){
	
		window.location.href = "<%=path%>/servlet/ProductAction?action_flag=search&pageNum="+currentPage;
	
	}
	 
	function selectAll(flag){
		
		var ids = document.getElementsByName("ids");
		for(var i = 0 ; i < ids.length ; i++){
			ids[i].checked = flag;
		}
	
	}
	
	function getSelectedCount(){
	
		var ids = document.getElementsByName("ids");
		var count = 0;
		for(var i = 0 ; i < ids.length ; i++)
		{
						
			ids[i].checked==true?count++:0;					
		}
		return count;
	
	}
	
	function del(){
	
		if(getSelectedCount()==0){
			
			alert("至少选择一个删除项！");
			return;
		
		}
		
		var th = document.form1;
		th.action="<%=path%>/servlet/ProductAction?action_flag=del";
		th.submit();		
	
	}
	
	function getSelectedValue(){
		var ids = document.getElementsByName("ids");
		
		for(var i = 0 ; i < ids.length ; i++)
		{
						
			if(ids[i].checked){
				return ids[i].value;
			}				
		}
		
	}
	
	function view(){
	
		if(getSelectedCount()<1){
			
			alert("至少选择一个查看项！");
			return;
		
		}else if(getSelectedCount()>1){
			alert("只能选择一个查看项！");
			return;
		}
		
		var th = document.form1;
		th.action="<%=path%>/servlet/ProductAction?action_flag=view&proid="+getSelectedValue();
		th.submit();		
	
	}
	
	function logout(){
	
	window.location.href="<%=path %>/servlet/LogoutAction?action_flag=logout";
		
	}
	
	
	</script>

  </head>
  
  <body>
   <div>
   <table width=60% align="center">
   <tr>
   		<td align="left"><font size=2>欢迎您的光临，<%=username%><br><a href="javascript:logout();">退出</a></font></td>
   </tr>
   	<tr>
   		<td align="center">
   		<form name = "form2" action="" method="post">
   		<table>
   			<tr>
   				<td colspan="2">产品信息查询</td>
   				
   			</tr>
   			<tr>
   				<td >产品名称</td>
   				<td ><input type="text" name="proname" value="<%= productName!=null?productName:"" %>"/></td>
   				
   			</tr>
   			
   			<tr>
   				<td colspan="2" align="center">
   					<button type="button" onclick="searchProduct()" >查询</button>
   					<button type="button" onclick="javascript:location.href=‘<%=path %>/addProduct.jsp‘">添加</button>   					
   					
   				</td>   				
   			</tr>   		
   		</table>  	
   		</form>	
   			
   		</td>
   	</tr>
   	
   	<tr>
   		<td height=50> </td>
   	</tr>
   	<tr>
   		<td> 查询结果</td>
   	</tr>
   	
   	<tr>
   	 	<td >
   	 	<form name="form1" action="" method="post">
   		<table border=1 width=100%>
   			<tr align="center">
   				<td width=10%><input type="checkbox" name="checkall" onclick="javascript:selectAll(this.checked);" /></td>
   				<td width=30%>产品名称</td>
   				<td width=30%>产品产地</td>
   				<td>产品价格</td>
   			
   			</tr>
   			<%
   			if(list!=null && !list.isEmpty()){
   			
   				for(Map<String,Object> map :list){%>
   			
   				<tr align="center">
   				<td width=10%><input type="checkbox" name="ids" value="<%=map.get("proid") %>"/></td>
   				<td width=30%><%=map.get("proname") %></td>
   				<td width=30%><%=map.get("proaddress") %></td>
   				<td><%=map.get("proprice") %></td>
   				
   				<%}
   			
   			
   			}else{%>
   			
   			<tr align="center">
   				<td width=10%><input type="checkbox" name="" /></td>
   				<td width=30%></td>
   				<td width=30%></td>
   				<td></td>
   			
   			</tr><%
   			
   			}   			
   			 %>
   			
   	
   			
   		
   		</table>   		
   		</form>
   		</td>
   	
   	</tr>
   	
   	<tr>
   		<td>
   			<button type="button" onclick="javascript:del();">删除</button>
   			<button type="button" onclick="javascript:view();" >查看</button>
   		
   		</td>
   	</tr>
   	
   	<tr>
   		<td colspan="4" align="center">
   			共<%=dividePage.getPageCount()  %>页    
   			<a href="javascript:first();">首页</a>   
   			<a href="javascript:forward();">上一页</a> 
   			<a href="javascript:next();">下一页</a> 
   			<a href="javascript:end();">尾页</a> 
   			跳转到<select name="select" onchange="changePage(this.value)">
   			
   			<%
   			int pageCount = dividePage.getPageCount();
   			if(pageCount>0){
   			for(int i = 1 ; i<=pageCount;i++){%>
   			
   			<option value="<%=i %>" <%= (i==dividePage.getCurrentPage()?"selected":"")%>>  <%=i %>
   			</option>
   			
   			<%			
   			}
   			
   			}else{// 无记录
   				%>
   				<option value="1">1</option>   
   			 <%}			
   			
   			%>
   					
   			</select>
   		
   		</td>
   	</tr>
   			
   
   
   
   
   </table>
   
   
   
   </div>
   
   
  </body>
</html>

原文  http://blog.csdn.net/neu_yousei/article/details/23943857

4.addProduct.jsp

<%@ 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%>">
	
	<title>新增产品</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" type="text/css" href="styles.css">
	-->
<script type="text/javascript">
function dosubmit(){
	var th = document.form1;
	th.action="<%= path%>/servlet/ProductAction?action_flag=add";
	th.submit();

}

</script>
  </head>
  
  <body>
	<div align="center">
	
		<table width=70% style="margin:auto;">
			<tr><td align="center" height=150 valign="bottom">产品信息添加</td></tr>
			<tr>
				<td>
					<form id="form1" name="form1" action="" method="post" enctype="multipart/form-data">
					<table border=1 style="margin:auto">
						<tr >
							<td>产品名称</td>
							<td><input type="text" name="proname" id="proname"/></td>
							<td>产品价格</td>
							<td><input type="text" name="proprice" id="proprice"/></td>
						</tr>
						<tr>
							<td>产品产地</td>
							<td colspan="3"><input type="text" name="proaddress" id="proaddress"/></td>
						</tr>
						<tr>
							<td>产品图片</td>
							<td colspan="3"><input type="file" name="proimage" id="proimage"  size=35/></td>
						</tr>
					
					</table> 
					</form>   				
				
				</td>
			</tr>
			<tr>
				<td colspan="4" align="center">
					<button type="button" onclick="javascript:dosubmit();">确定</button>
					<button type="button" onclick="javascript:location.href=‘main.jsp‘">返回</button>
				
				</td>
			</tr>
			
		
		</table>
		
	</div>
  </body>
</html>

5. viewProduct.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
Map<String,Object> map = (Map<String,Object>)request.getAttribute("productMap");

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>查看产品</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" type="text/css" href="styles.css">
	-->

  </head>
  
  <body>
  <div align="center">
  		
  		<table width=60% style="margin:auto">
  			
  			<tr>
  				<td height=100>
  					
  				</td>
  			</tr>
  			<tr>
  				<td >
  					产品信息
  				</td>
  			</tr>
  			<tr>
  				<td>
  					<table width = 99% border =1 >
	  					<tr align="center">
	  						<td width = 20%>产品名称</td>
	  						<td width = 30%><%=map.get("proname") %></td>
	  						<td width = 20%>产品价格</td>
	  						<td><%=map.get("proprice") %></td>
	  						
	  					
	  					</tr>
	  					<tr align="center">
	  						<td >产品产地</td>
	  						<td colspan=3><%=map.get("proaddress") %></td>					
	  						
	  					
	  					</tr>
	  					<tr align="center">
	  						<td>产品图片</td>
	  						<td colspan=3><img src="<%=path%>/upload/<%=map.get("proimage") %>"></td>	  						
	  					
	  					</tr>
  					
  					
  					</table>
  				</td>
  			</tr>
  			<tr>
  				<td align="center">
  					<button type="button" onclick="javascript:location.href=‘<%=path %>/main.jsp‘">确定</button>
  					<button type="button" onclick="javascript:history.go(-1)">返回</button>
  				</td>
  			</tr>
  		
  		</table>
  		
  	
  </div>
  </body>
</html>

6.LoginAction.java

package com.login;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LoginAction extends HttpServlet {

	private LoginService service;
	/**
	 * Constructor of the object.
	 */
	public LoginAction() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		this.doPost(request, response);
		
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html;charset=utf-8");
		PrintWriter out = response.getWriter();
		
		String path = request.getContextPath();
		String username = request.getParameter("username");
		String pswd = request.getParameter("pswd");
		
		List<Object> params = new ArrayList<Object>();
		params.add(username);
		params.add(pswd);
		boolean flag = service.login(params);
		
		if (flag) {
			
			request.getSession().setAttribute("username", username);
			response.sendRedirect(path+"/main.jsp");
		}else{
						
			response.sendRedirect(path+"/index.jsp");
		}
		
		
		
		
		out.flush();
		out.close();
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
		service = new LoginDao();
	}

}

7.LoginDao.java

package com.login;

import java.sql.SQLException;
import java.util.List;
import java.util.Map;

import javax.mail.Flags.Flag;

import com.jdbc.JdbcUtils;

public class LoginDao implements LoginService {

	private JdbcUtils jdbcUtils;
	public LoginDao() {
		// TODO Auto-generated constructor stub
		jdbcUtils = new JdbcUtils();
	}

	@Override
	public boolean login(List<Object> params) {
		// TODO Auto-generated method stub
		boolean flag = false;
		
		try {
			jdbcUtils.getConnection();
			String sql = "select * from userinfo where username = ? and pswd = ?";
			Map<String, Object> map = jdbcUtils.findSimpleResult(sql, params);
			flag = !map.isEmpty()?true:false;			
			
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}finally{
			
		//关闭数据库
		jdbcUtils.releaseConn();
			
		}
		
		return flag;
	}	

}

8.LoginService.java

package com.login;

import java.util.List;

public interface LoginService {

	public boolean login(List<Object> params);
}

9. MyFilter.java

package com.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyFilter implements Filter {

	public MyFilter() {
		// TODO Auto-generated constructor stub
	}

	@Override
	public void destroy() {
		// TODO Auto-generated method stub

	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain filterChain) throws IOException, ServletException {
		// 过滤用户请求，判断是否登录
		HttpServletRequest httpServletRequest = (HttpServletRequest)request;
		HttpServletResponse httpServletResponse = (HttpServletResponse)response;
		
		httpServletRequest.setCharacterEncoding("utf-8");
		httpServletResponse.setCharacterEncoding("utf-8");
		
		String username = (String)httpServletRequest.getSession().getAttribute("username");
		
		if (username == null) {
			String path = httpServletRequest.getContextPath();
			httpServletResponse.sendRedirect(path+"/index.jsp");
		}		
		filterChain.doFilter(httpServletRequest, httpServletResponse);
	}

	@Override
	public void init(FilterConfig arg0) throws ServletException {
		// TODO Auto-generated method stub

	}

}

10.RegisterAction.java

package com.register;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;



public class RegisterAction extends HttpServlet {	
	
	private RegisterService service;
	/**
	 * Constructor of the object.
	 */
	public RegisterAction() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		this.doPost(request, response);
		
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html;charset=utf-8");
		PrintWriter out = response.getWriter();
		String path = request.getContextPath();
		
		String username = request.getParameter("username");
		String pswd = request.getParameter("pswd");
		
		List<Object> params = new ArrayList<Object>();
		params.add(username);
		params.add(pswd); 	
		boolean flag = service.registerUser(params);
		if (flag) {
			response.sendRedirect(path+"/index.jsp");
		}
		
		
		
		out.flush();
		out.close();
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
		service = new RegisterDao();
	}

}

11. RegisterDao.java

package com.register;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.jdbc.JdbcUtils;

public class RegisterDao implements RegisterService {

	private JdbcUtils jdbcUtils;
	public RegisterDao() {
		// TODO Auto-generated constructor stub
		jdbcUtils = new JdbcUtils();
	}

	/* 完成对用户注册的dao的编写
	 * @see com.register.service.RegisterService#registerUser(java.util.List)
	 */
	@Override
	public boolean registerUser(List<Object> params) {
		// TODO Auto-generated method stub
		boolean flag = false;
		try {
			jdbcUtils.getConnection();
			String sql = "insert into userinfo(username,pswd) values(?,?)";			
			flag = jdbcUtils.updateByPreparedStatement(sql, params);
			
			
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}finally{
			//关闭数据库连接			
			jdbcUtils.releaseConn();
			
		}
		
		
		return flag;
	}

}

12. RegisterService.java

package com.register;

import java.util.List;

public interface RegisterService {
	
	//完成用户注册功能
	public boolean registerUser(List<Object> params);
}

13. ProductAction.java

package com.product;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.UUID;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;


import com.util.DividePage;
import com.util.UUIDTools;

public class ProductAction extends HttpServlet {

	private ProductService service;
	/**
	 * Constructor of the object.
	 */
	public ProductAction() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		this.doPost(request, response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html;charset=utf-8");
		request.setCharacterEncoding("utf-8");
		response.setCharacterEncoding("utf-8");
		PrintWriter out = response.getWriter();
		
		String action_flag = request.getParameter("action_flag");
		if (action_flag.equals("add")) {
			addProduct(request,response);
		}else if (action_flag.equals("search")) {
			listProduct(request,response);
		}else if (action_flag.equals("del")) {
			delProduct(request,response);
		}else if (action_flag.equals("view")) {
			viewProduct(request,response);
		}
		
		
		out.flush();
		out.close();
	}

	private void viewProduct(HttpServletRequest request,
			HttpServletResponse response) {
		// TODO Auto-generated method stub
		String proid = request.getParameter("proid");
		Map<String, Object> map = service.viewProduct(proid);
		request.setAttribute("productMap", map);
		try {
			request.getRequestDispatcher("/viewProduct.jsp").forward(request, response);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} 
		
	}

	/**批量删除产品
	 * @param request
	 * @param response
	 */
	private void delProduct(HttpServletRequest request,
			HttpServletResponse response) {
		// TODO Auto-generated method stub
		
		System.out.println("进入del");
		//获得复选框的值
		String[] ids = request.getParameterValues("ids");
		for (int i = 0; i < ids.length; i++) {
			System.out.println("ids["+i+"]="+ids[i]);
		}
		boolean flag = service.delProduct(ids);
		System.out.println("删除flag:"+flag);
		if (flag) {
			try {
				request.getRequestDispatcher("/main.jsp").forward(request, response);
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}		
	}

	private void listProduct(HttpServletRequest request,
			HttpServletResponse response) {
		// TODO Auto-generated method stub
		
		String productName = request.getParameter("proname");	
		String pageNum = request.getParameter("pageNum");
		System.out.println("参数 pageNum :"+pageNum);
		if (productName == null) {
			productName = "";
		}
		
		
		
		int totalRecord = service.getItemCount(productName); //获取总的记录数
		int currentPage = 1;
		DividePage dividePage = new DividePage(5, totalRecord);//默认第一页开始
		if (pageNum != null) {
			
			
			currentPage = Integer.parseInt(pageNum);
			
			dividePage.setCurrentPage(currentPage);
		}
		
		//记录从第几行开始
		int start = dividePage.fromIndex();
		//显示几条记录
		int end = dividePage.toIndex();		
		
		System.out.println("currentPageNum :"+ dividePage.getCurrentPage() +", start = "+start +", end = "+end);
		
		List<Map<String, Object>> list = null;
		try {
			list = service.listProduct(productName , start , end);
			request.setAttribute("listProduct", list);
			request.setAttribute("dividePage", dividePage);
			request.setAttribute("productName",productName );
			request.getRequestDispatcher("/main.jsp").forward(request, response);
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}		
		
	}

	private void addProduct(HttpServletRequest request, HttpServletResponse response) 
			throws ServletException, IOException{
		//表单含有文件要提交
		String  path = request.getContextPath();		
		DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();
		ServletFileUpload servletFileUpload = new ServletFileUpload(diskFileItemFactory);
		servletFileUpload.setFileSizeMax(3*1024*1024);//单个文件大小限制3M
		servletFileUpload.setSizeMax(6*1024*1024);//上传文件总大小
		List<FileItem> list = null;		
		List<Object> params = new ArrayList<Object>();
		params.add(UUIDTools.getUUID()); // 参数传 product表的主键
		try {
			//解析request的请求
			list = servletFileUpload.parseRequest(request);				
			//取出所有表单的值，判断非文本字段和文本字段
			for(FileItem fileItem : list){
				if (fileItem.isFormField()) {//是文本字段
					String fileItemName = fileItem.getFieldName(); //获取 <input>控件的 名称
					String fileItemValue = fileItem.getString("utf-8");//获取<input>控件的值
					if (fileItemName.equals("proname")) {
						params.add(fileItemValue); //参数传入 proname
					}else if (fileItemName.equals("proprice")) {
						params.add(fileItemValue);//参数传入 proprice
					}else if (fileItemName.equals("proaddress")) {
						params.add(fileItemValue);////参数传入 proaddress
					}					
				}else{ //非文本字段					
					
					String imageName = fileItem.getName(); //获取文件名称
					params.add(imageName);//参数传入  proimage			
					//String path = request.getRealPath("/upload");
					String upload_dir = request.getServletContext().getRealPath("/upload");//获取服务器端 /upload 路径
					File uploadFile = new File(upload_dir+"/"+imageName);
					System.out.println("---upload_dir--->>"+uploadFile);
					fileItem.write(uploadFile);						
				}				
			}
			
			// 把产品加入数据库
			boolean flag = service.addProduct(params);
			if (flag) {
				
				response.sendRedirect(path+"/main.jsp");
			}
				
			
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}
		
		
		
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
		service = new ProductDao();
	}

}

package com.product;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import com.jdbc.JdbcUtils;

public class ProductDao implements ProductService {

	private JdbcUtils jdbcUtils;
	public ProductDao() {
		// TODO Auto-generated constructor stub
		jdbcUtils = new JdbcUtils();
	}

	@Override
	public boolean addProduct(List<Object> params) {
		
		boolean flag = false;
		try {
			jdbcUtils.getConnection();
			String sql = "insert into product(proid,proname,proprice,proaddress,proimage) values(?,?,?,?,?)";
			flag = jdbcUtils.updateByPreparedStatement(sql, params);
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}finally{
			
			// 关闭数据库连接
			jdbcUtils.releaseConn();
			
		}
		
		
		return flag;
	}

	@Override
	public List<Map<String, Object>> listProduct(String proname ,int start ,int end) {
		// TODO Auto-generated method stub
		List<Map<String, Object>> list = new ArrayList<Map<String,Object>>();
		List<Object> params  = new ArrayList<Object>();		
		try {
			jdbcUtils.getConnection();			
			String sql = "select * from product where 1=1 and proname like ? limit ? ,?";	
			if(proname.equals("")){
				sql = "select * from product limit ? ,?";
				params.add(start);
				params.add(end);
				
			}else{				
				params.add("%"+proname+"%");
				params.add(start);
				params.add(end);
			}		
					
			list = jdbcUtils.findMoreResult(sql, params);			
			
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		} finally{
			
			
			jdbcUtils.releaseConn();
			
		}
		
		
		return list;
	}

	//查询总记录数
	@Override
	public int getItemCount(String proname) {
		// TODO Auto-generated method stub
		int count = 0;
		Map<String, Object> map = null;
		List<Object> params = null;		
		try {
			jdbcUtils.getConnection();			
			String sql = "select count(*) totalCount from product where 1=1 and proname like ?";	
			if(proname.equals("")){
				sql = "select count(*) totalCount from product";
				
			}else{
				params = new ArrayList<Object>();
				params.add("%"+proname+"%");
			}
		map = jdbcUtils.findSimpleResult(sql, params);
		count = Integer.parseInt(map.get("totalCount").toString());
			
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		} finally{
			// 关闭数据库连接
			jdbcUtils.releaseConn();
		}
		
		
		return count;
	}

	@Override
	public boolean delProduct(String[] ids) {
		boolean flag = false;
		try {
			jdbcUtils.getConnection();
			if (ids!=null) {
				String[] sql = new String[ids.length];
				for(int i = 0 ; i< ids.length; i++){
					sql[i] = "delete from product where proid = ‘"+ids[i]+"‘";
					System.out.println(sql[i]);
				}
				flag = jdbcUtils.deleteByBatch(sql);	
			}
					
			
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		} finally{
			// 关闭数据库连接
			jdbcUtils.releaseConn();
		}	
		
		return flag;
	}

	@Override
	public Map<String, Object> viewProduct(String proid) {
		// TODO Auto-generated method stub
		Map<String, Object> map = null;
		try {
			jdbcUtils.getConnection();
			List<Object> params = new ArrayList<Object>();
			params.add(proid);
			String sql = "select * from product where proid = ?";
			map = jdbcUtils.findSimpleResult(sql, params);
			
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		} finally{
			// 关闭数据库连接
			jdbcUtils.releaseConn();
		}
		
		
		return map;
	}

	

}

15. ProductService.java

package com.product;

import java.util.List;
import java.util.Map;

public interface ProductService {
	public boolean addProduct(List<Object> params);
	
	//列出产品,为了分页，加上参数 start,end
	public List<Map<String, Object>> listProduct(String proname , int start , int end);
	//获取总的记录数
	public int getItemCount(String proname);
	//批处理删除产品
	public boolean delProduct(String[] ids);
	//查询单个产品
	public Map<String, Object> viewProduct(String proid);
}

16. JdbcUtils.java

package com.jdbc;

import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap; 
import java.util.List;
import java.util.Map;

import com.mysql.jdbc.Driver;

public class JdbcUtils {

	// 定义数据库的用户名
	private final String USERNAME = "root";
	// 定义数据库的密码
	private final String PASSWORD = "123456";
	// 定义数据库的驱动信息
	private final String DRIVER = "com.mysql.jdbc.Driver";
	// 定义访问数据库的地址
	private final String URL = "jdbc:mysql://localhost:3306/mydb";

	// 定义访问数据库的连接
	private Connection connection;
	// 定义sql语句的执行对象
	private PreparedStatement pstmt;
	// 定义查询返回的结果集合
	private ResultSet resultSet;
	
	// 实现批处理的功能
	private Statement stmt;

	public JdbcUtils() {
		// TODO Auto-generated constructor stub
		try {
			Class.forName(DRIVER);
			System.out.println("注册驱动成功！！");
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			System.out.println("注册驱动失败！！");
		}

	}

	// 定义获得数据库的连接
	public Connection getConnection() {

		try {
			connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);

		} catch (Exception e) {
			// TODO: handle exception
			System.out.println("Connection exception !");
		}

		return connection;

	}
	
	
	
	/** 实现批处理删除
	 * @param sql
	 * @return
	 * @throws SQLException
	 */
	public boolean deleteByBatch(String[] sql) throws SQLException{
		boolean flag = false;
		stmt = connection.createStatement();
		if (sql!=null) { //判断数组是否为空，不能用length来判断，否则可能会报空指针异常。
			
			for(int i = 0 ; i<sql.length ; i++){
				stmt.addBatch(sql[i]);
			}
			
			int[] count = stmt.executeBatch();
			if (count!=null) {
				flag = true;
			}
			
		}	
		return flag;		
	}

	/**
	 * 完成对数据库标的增加删除和修改的操作
	 * 
	 * @param sql
	 * @param params
	 * @return
	 * @throws SQLException
	 */
	public boolean updateByPreparedStatement(String sql, List<Object> params)
			throws SQLException {
		boolean flag = false;
		int result = -1;// 表示当用户执行增加删除和修改的操作影响的行数
		int index = 1; // 表示 占位符 ，从1开始
		pstmt = connection.prepareStatement(sql);
		if (params != null && !params.isEmpty()) {
			for (int i = 0; i < params.size(); i++) {
				pstmt.setObject(index++, params.get(i)); // 填充占位符
			}
		}

		result = pstmt.executeUpdate();
		flag = result > 0 ? true : false;
		return flag;

	}

	/**
	 * 查询返回单条记录
	 * 
	 * @param sql
	 * @param params
	 * @return
	 * @throws SQLException
	 */
	public  Map<String, Object> findSimpleResult(String sql, List<Object> params)
			throws SQLException {
		Map<String, Object> map = new HashMap<String, Object>();
		pstmt = connection.prepareStatement(sql);
		int index = 1;
		if (params != null && !params.isEmpty()) {
			for (int i = 0; i < params.size(); i++) {
				pstmt.setObject(index++, params.get(i));
			}
		}
		resultSet = pstmt.executeQuery(); // 返回查询结果

		ResultSetMetaData metaData = pstmt.getMetaData(); // 获取 结果中，一行所有列的结果
		int cols_len = metaData.getColumnCount(); // 获得列的总数

		while (resultSet.next()) {
			for (int i = 0; i < cols_len; i++) {
				String col_name = metaData.getColumnName(i + 1); // 获得第i列的字段名称
				Object col_value = resultSet.getObject(col_name);// 返回 第i列的内容值
				if (col_value == null) {
					col_value = "";
				}
				map.put(col_name, col_value);
			}

		}

		return map;
	}

	/**
	 * 查询返回多条记录
	 * 
	 * @param sql
	 * @param params
	 * @return
	 * @throws SQLException
	 */
	public List<Map<String, Object>> findMoreResult(String sql,
			List<Object> params) throws SQLException {
		List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
		pstmt = connection.prepareStatement(sql);
		int index = 1; // 表示占位符
		if (params != null && !params.isEmpty()) {
			for (int i = 0; i < params.size(); i++) {
				pstmt.setObject(index++, params.get(i));
			}
		}
		resultSet = pstmt.executeQuery(); // 返回查询结果集合
		ResultSetMetaData metaData = resultSet.getMetaData(); // 获得列的结果

		while (resultSet.next()) {
			Map<String, Object> map = new HashMap<String, Object>();
			int cols_len = metaData.getColumnCount(); // 获取总的列数
			for (int i = 0; i < cols_len; i++) {
				String col_name = metaData.getColumnName(i + 1); // 获取第 i列的字段名称
																	// ,列计算从1开始
				Object col_value = resultSet.getObject(col_name); // 获取第i列的内容值
				if (col_value == null) {
					col_value = "";
				}

				map.put(col_name, col_value);
			}
			list.add(map);
		}

		return list;

	}

	/**
	 * 查询返回单个JavaBean(使用java反射机制)
	 * 
	 * @param sql
	 * @param params
	 * @param cls
	 * @return
	 * @throws Exception
	 */
	public <T> T findSimpleRefResult(String sql, List<Object> params,
			Class<T> cls) throws Exception {
		T resultObject = null;
		int index = 1; // 占位符
		pstmt = connection.prepareStatement(sql);
		if (params != null && !params.isEmpty()) {
			for (int i = 0; i < params.size(); i++) {
				pstmt.setObject(index++, params.get(i)); // 填充占位符
			}
		}
		resultSet = pstmt.executeQuery(); // 获取查询结果

		ResultSetMetaData metaData = resultSet.getMetaData(); // 获取列的信息
		int cols_len = metaData.getColumnCount(); // 获取总的列数
		while (resultSet.next()) {
			// 通过反射机制创建实例
			resultObject = cls.newInstance(); // java反射机制
			for (int i = 0; i < cols_len; i++) {
				String col_name = metaData.getColumnName(i + 1); // 获取第i列的名称
				Object col_value = resultSet.getObject(col_name); // 获取第i列的值
				if (col_value == null) {
					col_value = "";
				}
				Field field = cls.getDeclaredField(col_name);
				field.setAccessible(true);// 打开 JavaBean的访问 private权限
				field.set(resultObject, col_value);
			}

		}

		return resultObject;
	}

	/** 查询返回多个JavaBean(通过java反射机制)
	 * @param sql
	 * @param params
	 * @param cls
	 * @return
	 * @throws Exception
	 */
	public <T> List<T> findMoreRefResult(String sql, List<Object> params,
			Class<T> cls) throws Exception {
		List<T> list = new ArrayList<T>();
		int index = 1; //占位符
		pstmt = connection.prepareStatement(sql);
		if (params != null && !params.isEmpty()) {
			for (int i = 0; i < params.size(); i++) {
				pstmt.setObject(index++, params.get(i));
			}
		}
		resultSet = pstmt.executeQuery(); // 返回查询结果集合

		ResultSetMetaData metaData = resultSet.getMetaData(); // 返回列的信息
		int cols_len = metaData.getColumnCount(); // 结果集中总的列数
		while (resultSet.next()) {
			// 通过反射机制创建一个java实例
			T resultObject = cls.newInstance();
			for (int i = 0; i < cols_len; i++) {
				String col_name = metaData.getColumnName(i + 1); // 获得第i列的名称
				Object col_value = resultSet.getObject(col_name); // 获得第i列的内容
				if (col_value == null) {
					col_value = "";
				}
				Field field = cls.getDeclaredField(col_name);
				field.setAccessible(true); // 打开JavaBean的访问private权限
				field.set(resultObject, col_value);
			}
			list.add(resultObject);

		}

		return list;
	}
	
	/**关闭数据库访问
	 * @throws SQLException
	 */
	public void releaseConn(){
		if (resultSet!=null) {
			try {
				resultSet.close();
			} catch (Exception e) {
				// TODO: handle exception
				e.printStackTrace();
			}
			
		}
		if(stmt!=null){
			
			try {
				stmt.close();
			} catch (Exception e) {
				// TODO: handle exception
				e.printStackTrace();
			}
		}
		if (pstmt!=null) {
			try {
				pstmt.close();
			} catch (Exception e) {
				// TODO: handle exception
				e.printStackTrace();
			}
		}
		if (connection!=null) {
			try {
				connection.close();
			} catch (Exception e) {
				// TODO: handle exception
				e.printStackTrace();
			}
		}
	}

	
}

17. DividePage.java

package com.util;

public class DividePage {

	private int pageSize ; //每一页的记录数
	private int totalRecord;//总记录数
	private int currentPage;//当前第几页
	public DividePage(int pageSize, int totalRecord, int currentPage) {		
		this.pageSize = pageSize;
		this.totalRecord = totalRecord;
		setCurrentPage(currentPage);		
		
	}
	public DividePage(int pageSize, int totalRecord) {		
		this(pageSize,totalRecord,1);	
		
	}
	
	//获取总页数
	public int getPageCount(){		
		int pageCount = totalRecord/pageSize;
		int mod = totalRecord%pageSize;
		if (mod!=0) {
			pageCount++;
		}		
		return pageCount;		
	}
	
	// mysql : select * from product limit 5,10  表示查询记录行 第6到15行。
	
	//起始记录从第几行开始(mysql 记录默认从第0行开始)
	public int fromIndex(){
		
		return (currentPage-1)*pageSize;
	}
	
	//要查询的的尾记录相对于起始记录的偏移量，即一页的记录数
	public int toIndex(){
		return pageSize;
	}
	
	public void setCurrentPage( int currentPage){		
		
		if (getPageCount()!=0) {//有记录
			
			int validPage = currentPage<1?1:currentPage;
			validPage = validPage>getPageCount()?getPageCount():validPage;		
			this.currentPage = validPage;
		} else{ // 0条记录
			this.currentPage = 1;
		}
		
	}
	public int getPageSize() {
		return pageSize;
	}
	public void setPageSize(int pageSize) {
		this.pageSize = pageSize;
	}
	public int getTotalRecord() {
		return totalRecord;
	}
	public void setTotalRecord(int totalRecord) {
		this.totalRecord = totalRecord;
	}
	public int getCurrentPage() {
		return currentPage;
	}
	
	
}

18. UUIDTools.java

package com.util;

import java.util.UUID;

public class UUIDTools {

	public UUIDTools() {
		// TODO Auto-generated constructor stub
	}
	
	/**返回一个 6位的字符串
	 * @return
	 */
	public static String getUUID(){
		
		UUID uuid = UUID.randomUUID();
		return uuid.toString().replaceAll("-", "").substring(0, 6); 
		
	}

}

20. LogoutAction.java

package com.logout;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LogoutAction extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public LogoutAction() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		this.doPost(request, response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html;charset=utf-8");
		request.setCharacterEncoding("utf-8");
		response.setCharacterEncoding("utf-8");
		String path = request.getContextPath();
		String action_flag = request.getParameter("action_flag");
		if (action_flag.equals("logout")) {
			request.getSession().removeAttribute("username");
			response.sendRedirect(path+"/index.jsp");
		}
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}

21. web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" 
	xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
  <display-name></display-name>
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>RegisterAction</servlet-name>
    <servlet-class>com.register.RegisterAction</servlet-class>
  </servlet>
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>LoginAction</servlet-name>
    <servlet-class>com.login.LoginAction</servlet-class>
  </servlet>
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>ProductAction</servlet-name>
    <servlet-class>com.product.ProductAction</servlet-class>
  </servlet>
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>LogoutAction</servlet-name>
    <servlet-class>com.logout.LogoutAction</servlet-class>
  </servlet>


  
  <servlet-mapping>
    <servlet-name>RegisterAction</servlet-name>
    <url-pattern>/servlet/RegisterAction</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>LoginAction</servlet-name>
    <url-pattern>/servlet/LoginAction</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>ProductAction</servlet-name>
    <url-pattern>/servlet/ProductAction</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>LogoutAction</servlet-name>
    <url-pattern>/servlet/LogoutAction</url-pattern>
  </servlet-mapping>
 
  
  <!-- 配置 过滤器 -->
  
  <filter>
  	<filter-name>MyFilter</filter-name>
  	<filter-class>com.filter.MyFilter</filter-class>
  </filter>
 
  <filter-mapping>
  	<filter-name>MyFilter</filter-name>
  	<!-- /*表示过滤所有页面 ，/main.jsp 表示只过滤main.jsp页面-->
  	<url-pattern> /main.jsp</url-pattern>   
  </filter-mapping>
   <filter-mapping>
  	<filter-name>MyFilter</filter-name>
  	<!-- /*表示过滤所有页面 /addProduct.jsp 表示只过滤addProduct.jsp页面-->
  	<url-pattern>/addProduct.jsp</url-pattern>   
  </filter-mapping>
  

  
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

注意：

1. 使用过滤器，要引入jar包：servlet-2_5-api.jar

2. 使用jdbc连接mysql , 要引入jar包：mysql-connector-java-5.1.7-bin.jar

3. 文件上传，要引入2个jar包：

commons-fileupload-1.3.1.jar 和

commons-io-2.4.jar

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