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)
{
https://www.doczj.com/doc/4e859766.html,er = user;
return true;
}
public String getUser()
{
return https://www.doczj.com/doc/4e859766.html,er;
}
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
//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 = "
";
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(),s tr3);
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 https://www.doczj.com/doc/4e859766.html,st();
}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(!https://www.doczj.com/doc/4e859766.html,erNotExit(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.c om"));
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 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(); https://www.doczj.com/doc/4e859766.html,ername = this.getCookieValue(myCookies,cookieName,"not found"); PrintWriter out = res.getWriter(); if(https://www.doczj.com/doc/4e859766.html,ername != null) { //out.println("早上好，" + https://www.doczj.com/doc/4e859766.html,ername + "！"); return true; }else{ out.println("登陆失败！"); return false; } } public String getUserName() { return https://www.doczj.com/doc/4e859766.html,ername; } public static String getCookieValue(Cookie[] cookies,String cookieName,String defaultValue) { for(int i=0;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" %>
<%
boolean login = checklogin.check(request,response);
%>