声明：作者原创，版权所有。未经授权，不得转载
在jsp中用bean和servlet联合实现用户注册、登录

作者：imagebear
版权：imagebear

本例需要的软件和运行环境：
1、Windows2000 Server操作系统
2、jdk1.4
3、JCreator2.5（java源码编辑调试器，吐血推荐！）
4、Macromedia JRun MX
5、Macromedia Dreamweaver MX（非必需）
6、MySQL数据库（最好安装MySQL Control Center）

一、数据库设计
用MySQL Control Center打开MySQL数据库，新建数据库shopping，在其下新建表tbl_user，其中各字段设置如下：

二、编写连接数据库bean：DBConn.java

//DBConn.java

//include required classes
import java.sql.*;

//==========================================
// Define Class DBConn
//==========================================
public class DBConn
{
public String sql_driver = "org.gjt.mm.mysql.Driver";
public String sql_url = "jdbc:mysql://localhost:3306";
public String sql_DBName = "shopping";
public String user = "sa";
public String pwd = ";

Connection conn = null;
Statement stmt = null;
ResultSet rs = null;

public boolean setDriver(String drv)
{
this.sql_driver = drv;
return true;
}

public String getDriver()
{
return this.sql_driver;
}

public boolean setUrl(String url)
{
this.sql_url = url;
return true;
}

public boolean setDBName(String dbname)
{
this.sql_DBName = dbname;
return true;
}

public String getDBName()
{
return this.sql_DBName;
}

public boolean setUser(String user)
{
this.user = user;
return true;
}

public String getUser()
{
return this.user;
}

public boolean setPwd(String pwd)
{
this.pwd = pwd;
return true;
}

public String getPwd()
{
return this.pwd;
}

public DBConn()
{
try{
Class.forName(sql_driver);//加载数据库驱动程序
this.conn = DriverManager.getConnection(sql_url + "/" + sql_DBName + "?user=" + user + "&password=" + pwd + "&useUnicode=true&characterEncoding=gb2312");
this.stmt = this.conn.createStatement();
}catch(Exception e){
System.out.println(e.toString());
}
}

//执行查询操作
public ResultSet executeQuery(String strSql)
{
try{
this.rs = stmt.executeQuery(strSql);
return this.rs;
}catch(SQLException e){
System.out.println(e.toString());
return null;
}catch(NullPointerException e){
System.out.println(e.toString());
return null;
}
}

//执行数据的插入、删除、修改操作
public boolean execute(String strSql)
{
try{
if(this.stmt.executeUpdate(strSql) == 0)
return false;
else
return true;
}catch(SQLException e){
System.out.println(e.toString());
return false;
}catch(NullPointerException e){
System.out.println(e.toString());
return false;
}
}

//结果集指针跳转到某一行
public boolean rs_absolute(int row)
{
try{
this.rs.absolute(row);
return true;
}catch(SQLException e){
System.out.println(e.toString());
return false;
}
}

public void rs_afterLast()
{
try{
this.rs.afterLast();
}catch(SQLException e){
System.out.println(e.toString());
}
}

public void rs_beforeFirst()
{
try{
this.rs.beforeFirst();
}catch(SQLException e){
System.out.print(e.toString());
}
}

public void rs_close()
{
try{
this.rs.close();
}catch(SQLException e){
System.out.print(e.toString());
}
}

public void rs_deleteRow()
{
try{
this.rs.deleteRow();
}catch(SQLException e){
System.out.print(e.toString());
}
}

public boolean rs_first()
{
try{
this.rs.first();
return true;
}catch(SQLException e){
System.out.print(e.toString());
return false;
}
}

public String rs_getString(String column)
{
try{
return this.rs.getString(column);
}catch(SQLException e){
System.out.println(e.toString());
return null;
}
}

//此方法用于获取大段文本，
//将其中的回车换行替换为<br>
//输出到html页面
public String rs_getHtmlString(String column)
{
try{
String str1 = this.rs.getString(column);
String str2 = "\r\n";
String str3 = "<br>";
return this.replaceAll(str1,str2,str3);
}catch(SQLException e){
System.out.println(e.toString());
return null;
}
}

//把str1字符串中的str2字符串替换为str3字符串
private static String replaceAll(String str1,String str2,String str3)
{
StringBuffer strBuf = new StringBuffer(str1);
int index=0;
while(str1.indexOf(str2,index)!=-1)
{
index=str1.indexOf(str2,index);
strBuf.replace(str1.indexOf(str2,index),str1.indexOf(str2,index)+str2.length(),str3);
index=index+str3.length();

str1=strBuf.toString();
}
return strBuf.toString();
}

public int rs_getInt(String column)
{
try{
return this.rs.getInt(column);
}catch(SQLException e){
System.out.println(e.toString());
return -1;
}
}

public int rs_getInt(int column)
{
try{
return this.rs.getInt(column);
}catch(SQLException e){
System.out.println(e.toString());
return -1;
}
}

public boolean rs_next()
{
try{
return this.rs.next();
}catch(SQLException e){
System.out.println(e.toString());
return false;
}
}

//判断结果集中是否有数据
public boolean hasData()
{
try{
boolean has_Data = this.rs.first();
this.rs.beforeFirst();
return has_Data;
}catch(SQLException e){
System.out.println(e.toString());
return false;
}
}

public boolean rs_last()
{
try{
return this.rs.last();
}catch(SQLException e){
System.out.println(e.toString());
return false;
}
}

public boolean rs_previous()
{
try{
return this.rs.previous();
}catch(Exception e){
System.out.println(e.toString());
return false;
}
}

//main方法，调试用
public static void main(String args[])
{
try{
DBConn myconn = new DBConn();
//myconn.setDBName("shopping");
//myconn.DBConn();
//myconn.execute("Insert Into tbl_test(id,name) values('10','shandaer')");
//myconn.execute("Update tbl_test set name='yyyyyyyyyyyy' where id=10");
//myconn.execute("Delete from tbl_test where id=1");
ResultSet rs = myconn.executeQuery("select * from tbl_user order by id desc limit 1");
//boolean hasData = myconn.hasData();
//System.out.println("has data:" + hasData);
//rs.first();
while (myconn.rs.next())
{
int id = myconn.rs_getInt("id") + 1;
System.out.print(id);
System.out.println(myconn.rs_getInt("id") + myconn.rs_getString("name"));

//System.out.println('\n' + myconn.rs_getHtmlString("name"));
//System.out.println(myconn.rs.getString("name") + myconn.rs_getInt(1));
}
}catch(Exception e){
System.err.println(e.toString());
}
}

}

声明：因为使用的是MySQL数据库，所以需要MySQL数据库的驱动
下载后请将org包放至DBConn.java所在目录下
以确保该bean能正常运行

三、编写用户注册的bean：reg.java

//reg.java

//import required classes
import java.sql.*;

public class reg
{
public int newID = 0;
public boolean result = false;
public boolean reg(String username,String password,String confirm,String email)
{
try{
if(!this.checkUser(username))
return false;
if(!this.checkPwd(password))
return false;
if(!this.verifyPwd(password,confirm))
return false;
if(!this.checkEmail(email))
return false;
if(!this.userNotExit(username))
return false;
this.getNewID();
this.result = this.register(username,password,confirm,email);
return this.result;
}catch(Exception e){
System.out.println(e.toString());
return false;
}
}//End boolean reg

public boolean checkUser(String user)
{
try{
if(user.indexOf("'")!=-1)
{
System.out.println("姓名中含有非法字符！");
return false;
}else
return true;
}catch(Exception e){
System.out.println(e.toString());
return false;
}
}

public boolean checkPwd(String pwd)
{
try{
if(pwd.indexOf("'")!=-1)
{
System.out.println("密码中含有非法字符！");
return false;
}else
return true;
}catch(Exception e){
System.out.println(e.toString());
return false;
}
}

public boolean verifyPwd(String pwd,String confirm)
{
try{
if(!pwd.equals(confirm))
{
System.out.println("两次输入的密码不一致！");
return false;
}else
return true;
}catch(Exception e){
System.out.println(e.toString());
return false;
}
}

public boolean checkEmail(String email)
{
try{
if(email.indexOf("'")!=-1)
{
System.out.println("E-mail中含有非法字符！");
return false;
}else
return true;
}catch(Exception e){
System.out.println(e.toString());
return false;
}
}

public boolean userNotExit(String user)
{
try{
DBConn userDBConn = new DBConn();
userDBConn.executeQuery("select * from tbl_user where name='" + user + "'");
if(userDBConn.rs_next())
{
System.out.println("用户名已存在，请选择其它的用户名！");
return false;
}else
return true;
}catch(Exception e){
System.out.println(e.toString());
return false;
}
}

public int getNewID()
{
try{
DBConn newIDDBConn = new DBConn();
newIDDBConn.executeQuery("select * from tbl_user order by id desc limit 1");
if(newIDDBConn.rs_next())
{
this.newID = newIDDBConn.rs_getInt("id") + 1;
System.out.println(this.newID);
}else{
this.newID = 1;
}
return this.newID;
}catch(Exception e){
System.out.println(e.toString());
return -1;
}
}

public int getID()
{
return this.newID;
}

public boolean register(String username,String password,String confirm,String email)
{
try{
DBConn regDBConn = new DBConn();
String strSQL = "insert into tbl_user(id,name,pwd,email) values('" + this.newID +"','" + username + "','" + password + "','" + email + "')";
regDBConn.execute(strSQL);
return true;
}catch(Exception e){
System.out.println(e.toString());
return false;
}
}

public static void main(String args[])
{
try{

reg newreg = new reg();

System.out.println(newreg.reg("sssssssss","ssssss","ssssss","imagebear@163.com"));

DBConn myconn = new DBConn();
myconn.executeQuery("select * from tbl_user");
while(myconn.rs_next())
{
System.out.println(myconn.rs_getInt("id") + " " + myconn.rs_getString("name") + " " + myconn.rs_getString("pwd") + " " + myconn.rs_getString("email"));
}
System.out.println(newreg.getID());
}catch(Exception e){
System.err.println(e.toString());
}
}
};

说明：
1、该bean文件应和上文所述DBConn.class文件放于同一目录下
2、本例主要研究注册的过程，其中的Email检测等方法并不完善，若要应用请自行设计方法

四、编写用户登陆的Servlet：login.java

//login.java

//import required classes
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;

//class login
public class login extends HttpServlet
{
public void doGet(HttpServletRequest req,HttpServletResponse res)
throws IOException,ServletException
{
String username = req.getParameter("username");
String password = req.getParameter("password");
if(this.checklogin(username,password))
{
Cookie mylogin = new Cookie("username",username);
mylogin.setVersion(1);
mylogin.setPath("/");
mylogin.setComment("Your login username");
res.addCookie(mylogin);
}
//Cookie[] myCookies = req.getCookies();
//String nameValue = this.getCookieValue(myCookies,"username","not found");
//PrintWriter out = res.getWriter();
//out.println("username" + ":" + nameValue);
//out.println("Test Cookie Success!");
res.sendRedirect("/index.jsp");
}

public void doPost(HttpServletRequest req,HttpServletResponse res)
throws IOException,ServletException
{
doGet(req,res);
}

public static String getCookieValue(Cookie[] cookies,String cookieName,String defaultValue)
{
for(int i=0;i<cookies.length;i++) {
Cookie cookie = cookies[i];
if (cookieName.equals(cookie.getName()))
return(cookie.getValue());
}
return(defaultValue);
}

public boolean checklogin(String username,String password)
{
try{
DBConn loginConn = new DBConn();
loginConn.executeQuery("select * from tbl_user where name='" + username + "'");
if(loginConn.rs_next())
{
System.out.println("Connection created!");
if(loginConn.rs_getString("pwd").trim().equals(password))
{
System.out.println(loginConn.rs_getString("name"));
return true;
}
else
{
return false;
}
}
System.out.println("Test Login Success!");
return false;
}catch(Exception e){
System.out.println(e.toString());
return false;
}
}

public static void main(String args[])
{
login mylogin = new login();
System.out.println(mylogin.checklogin("shandong","shandong"));
}

}

说明：
1、默认的jdk1.4中并没有servlet包，请至sun公司网页下载servlet.jar，放至jdk目录下的jre\lib\目录下，并在JCreator中设置jdk处添加servlet.jar包

2、本Servlet用于检验用户名和密码，若正确则将用户名写入Cookie，完成后将当前页重定向到index.jsp页

五、编写检测用户是否已经登陆的bean：checkLogin.java

//checkLogin.java

//import required classes
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

//class checkLogin
public class checkLogin
{
public String username = ";

public boolean check(HttpServletRequest req,HttpServletResponse res)
throws IOException,ServletException
{
String cookieName = "username";
Cookie[] myCookies = req.getCookies();
this.username = this.getCookieValue(myCookies,cookieName,"not found");
PrintWriter out = res.getWriter();
if(this.username != null)
{
//out.println("早上好，" + this.username + "！");
return true;
}else{
out.println("登陆失败！");
return false;
}

}

public String getUserName()
{
return this.username;
}

public static String getCookieValue(Cookie[] cookies,String cookieName,String defaultValue)
{
for(int i=0;i<cookies.length;i++) {
Cookie cookie = cookies[i];
if (cookieName.equals(cookie.getName()))
return(cookie.getValue());
}
return(defaultValue);
}
}

说明：此bean检测cookie中的username，若不为空则说明已登录，反之说明没有登录。方法不够完善，您可以自行扩充。

六、在JRun中建立shopping服务器
打开JRun Administrator，新建shopping服务器，这里端口为8101。
将上文所述所有编译后的class文件连同org包拷至JRun的shopping服务器所在目录中的classes文件夹下，路径为：

C:\JRun4\servers\shopping\default-ear\default-war\WEB-INF\classes\

七、建立jsp文件
应用DW，在C:\JRun4\servers\shopping\default-ear\default-war\目录下新建如下的jsp文件：
index.jsp：

<%@ page contentType="text/html;charset=gb2312" pageEncoding="gb2312" %>
<html>
<head>
<title>Shopping123</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<link href="styles/shoppingstyle.css" rel="stylesheet" type="text/css">
</head>
<body bgcolor="#FFFFFF" leftmargin="0" topmargin="0">
<jsp:useBean id="checklogin" class="checkLogin" scope="page"/>
<%
boolean login = checklogin.check(request,response);
%>
<table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0">
<tr bgcolor="#990000">
<td height="80" colspan="5"><table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="120">&nbsp;</td>
<td class="caption">Shopping123</td>
<td width="200">&nbsp;</td>
</tr>
</table></td>
</tr>
<tr>
<td width="200" align="center" valign="top"><table width="100%" height="20" border="0" cellpadding="0" cellspacing="0">
<tr>
<td>&nbsp;</td>
</tr>
</table>
<%
if(!login){
%>
<table width="90%" border="0" align="center" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
<form name="form1" method="post" action="/servlet/login">
<tr align="center" bgcolor="#CCCCCC">
<td height="30" colspan="2" class="deepred">卖场入口</td>
</tr>
<tr>
<td width="50%" height="24" align="center" bgcolor="#FFFFFF">会员</td>
<td align="center" bgcolor="#FFFFFF"><input name="username" type="text" id="username" size="10"></td>
</tr>
<tr>
<td height="24" align="center" bgcolor="#FFFFFF">密码</td>
<td align="center" bgcolor="#FFFFFF"><input name="password" type="text" id="password" size="10"></td>
</tr>
<tr>
<td height="24" align="center" bgcolor="#FFFFFF"><a href="reg.jsp" target="_blank" class="red">注册</a></td>
<td align="center" bgcolor="#FFFFFF"><input type="submit" name="Submit" value="进入"></td>
</tr>
</form>
</table>
<%
}
else
{
out.println("您好，" + checklogin.getUserName() + "!");
}
%>
</td>
<td width="1" valign="top" bgcolor="#CCCCCC"></td>
<td width="400">&nbsp;</td>
<td width="1" valign="top" bgcolor="#CCCCCC"></td>
<td width="200">&nbsp;</td>
</tr>
<tr align="center" bgcolor="#990000">
<td height="60" colspan="5" class="white">copyright&copy; 2003 Shopping123</td>
</tr>
</table>
</body>
</html>

reg.jsp<%@ page contentType="text/html;charset=gb2312" pageEncoding="gb2312" %>
<html>
<head>
<title>Shopping123</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<link href="styles/shoppingstyle.css" rel="stylesheet" type="text/css">
</head>
<body bgcolor="#FFFFFF" leftmargin="0" topmargin="0">
<table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0">
<tr bgcolor="#990000">
<td height="80" colspan="5"><table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="120">&nbsp;</td>
<td class="caption">Shopping123</td>
<td width="200">&nbsp;</td>
</tr>
</table></td>
</tr>
<tr>
<td width="100" align="center" valign="top">&nbsp;</td>
<td width="1" valign="top"></td>
<td width="400" align="center" valign="top"><table width="100%" height="20" border="0" cellpadding="0" cellspacing="0">
<tr>
<td>&nbsp;</td>
</tr>
</table>
<table width="100%" border="0" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
<form action="regpost.jsp" method="post" name="form1">
<tr align="center">
<td height="30" colspan="2" bgcolor="#CCCCCC" class="deepred">会员注册</td>
</tr>
<tr>
<td width="50%" height="24" align="center" bgcolor="#FFFFFF">会员</td>
<td align="center" bgcolor="#FFFFFF"><input name="username" type="text" id="username" size="16"></td>
</tr>
<tr>
<td width="50%" height="24" align="center" bgcolor="#FFFFFF">密码</td>
<td align="center" bgcolor="#FFFFFF"><input name="password" type="password" id="password" size="16"></td>
</tr>
<tr>
<td width="50%" height="24" align="center" bgcolor="#FFFFFF">验证密码</td>
<td align="center" bgcolor="#FFFFFF"><input name="confirm" type="password" id="confirm" size="16"></td>
</tr>
<tr>
<td width="50%" height="24" align="center" bgcolor="#FFFFFF">E-mail</td>
<td align="center" bgcolor="#FFFFFF"><input name="email" type="text" id="email" size="16"></td>
</tr>
<tr>
<td width="50%" height="24" align="center" bgcolor="#FFFFFF"><input type="submit" name="Submit" value="重写"></td>
<td align="center" bgcolor="#FFFFFF"><input type="submit" name="Submit2" value="注册"></td>
</tr>
</form>
</table></td>
<td width="1" valign="top"></td>
<td width="100">&nbsp;</td>
</tr>
<tr align="center" bgcolor="#990000">
<td height="60" colspan="5" class="white">copyright&copy; 2003 Shopping123</td>
</tr>
</table>
</body>
</html>
regpost.jsp：注册表单提交页面<%@ page contentType="text/html;charset=gb2312" pageEncoding="gb2312" %>
<%@ page import="reg"%>
<html>
<head>
<title>Shopping123</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<link href="styles/shoppingstyle.css" rel="stylesheet" type="text/css">
</head>
<body bgcolor="#FFFFFF" leftmargin="0" topmargin="0">
<%
String username = new String(request.getParameter("username").getBytes("ISO8859_1")).trim();
String password = new String(request.getParameter("password").getBytes("ISO8859_1")).trim();
String confirm = new String(request.getParameter("confirm").getBytes("ISO8859_1")).trim();
String email = new String(request.getParameter("email").getBytes("ISO8859_1")).trim();
%>
<table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0">
<tr bgcolor="#990000">
<td height="80" colspan="5"><table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="120">&nbsp;</td>
<td class="caption">Shopping123</td>
<td width="200">&nbsp;</td>
</tr>
</table></td>
</tr>
<tr>
<td width="100" align="center" valign="top">&nbsp;</td>
<td width="1" valign="top"></td>
<td width="400" align="center" valign="top">
<table width="100%" height="20" border="0" cellpadding="0" cellspacing="0">
<tr>
<td>&nbsp;</td>
</tr>
</table>
<jsp:useBean id="regID" class="reg" scope="session"/>
<%
if(regID.reg(username,password,confirm,email))
{
out.print("ok");
String newID = regID.getID() + ";
%>
<table width="100%" border="0" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
<tr align="center">
<td height="30" colspan="2" bgcolor="#CCCCCC" class="deepred">恭喜您，注册成功！</td>
</tr>
<tr>
<td width="50%" height="24" align="center" bgcolor="#FFFFFF">编号</td>
<td align="center" bgcolor="#FFFFFF"><%=newID%></td>
</tr>
<tr>
<td width="50%" height="24" align="center" bgcolor="#FFFFFF">会员</td>
<td align="center" bgcolor="#FFFFFF"><%=username%></td>
</tr>
<tr>
<td width="50%" height="24" align="center" bgcolor="#FFFFFF">密码</td>
<td align="center" bgcolor="#FFFFFF"><%=password%></td>
</tr>
<tr>
<td width="50%" height="24" align="center" bgcolor="#FFFFFF">E-mail</td>
<td align="center" bgcolor="#FFFFFF"><%=email%></td>
</tr>
</table>
<%
out.print("<br>");
out.print("<a href=javascript:window.close()>关闭</a>");
}else{
out.print("注册失败！<br>");
out.print("该用户名已有人使用，请使用另外的用户名！");
out.print("<a href=javascript:history.go(-1)>返回</a>");
}
%>
</td>
<td width="1" valign="top"></td>
<td width="100">&nbsp;</td>
</tr>
<tr align="center" bgcolor="#990000">
<td height="60" colspan="5" class="white">copyright&copy; 2003 Shopping123</td>
</tr>
</table>
</body>
</html>
至此，我们已经完成了一个用户注册、登录的系统。 因为这是本人自己边学边做完成的，所以代码一定有很多不完善的地方，欢迎大家批评指正。 以上所有代码均经本人测试通过。