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"> </td>
<td class="caption">shopping123</td>
<td width="200"> </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> </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"> </td>
<td width="1" valign="top" bgcolor="#cccccc"></td>
<td width="200"> </td>
</tr>
<tr align="center" bgcolor="#990000">
<td height="60" colspan="5" class="white">copyright© 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"> </td>
<td class="caption">shopping123</td>
<td width="200"> </td>
</tr>
</table></td>
</tr>
<tr>
<td width="100" align="center" valign="top"> </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> </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"> </td>
</tr>
<tr align="center" bgcolor="#990000">
<td height="60" colspan="5" class="white">copyright© 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"> </td>
<td class="caption">shopping123</td>
<td width="200"> </td>
</tr>
</table></td>
</tr>
<tr>
<td width="100" align="center" valign="top"> </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> </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"> </td>
</tr>
<tr align="center" bgcolor="#990000">
<td height="60" colspan="5" class="white">copyright© 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。
