登陆注册案例

一、项目目录结构：

  案例采用MVC三层模式开发：

 

二、源代码：

  domain层：User .java

package com.domain;

import java.util.Date;

public class User {
    private String id;
    private String username;
    private String password;
    private String email;
    private Date birthday;
    private String nickname;
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public Date getBirthday() {
        return birthday;
    }
    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
    public String getNickname() {
        return nickname;
    }
    public void setNickname(String nickname) {
        this.nickname = nickname;
    }
}

dao层：UserDaoImpl .java

package com.dao.impl;
import java.text.SimpleDateFormat;

import org.dom4j.Document;
import org.dom4j.Element;

import com.dao.UserDao;
import com.domain.User;
import com.utils.XmlUtils;


public class UserDaoImpl implements UserDao {

    public void add(User user){
        try{
            Document document = XmlUtils.getDocument();
            Element root = document.getRootElement();
            
            Element user_tag = root.addElement("user");
            user_tag.setAttributeValue("id", user.getId());
            user_tag.setAttributeValue("username", user.getUsername());
            user_tag.setAttributeValue("password", user.getPassword());
            user_tag.setAttributeValue("email", user.getEmail());
            user_tag.setAttributeValue("birthday", user.getBirthday()==null?"":user.getBirthday().toLocaleString());
            user_tag.setAttributeValue("nickname", user.getNickname());
        
            XmlUtils.reWrite(document);
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    
    public User find(String username,String password){
        try{
            Document document = XmlUtils.getDocument();
            Element e = (Element) document.selectSingleNode("//user[@username='"+username+"' and @password='"+password+"']");
            if(e==null){
                return null;
            }
            User user = new User();
            String date = e.attributeValue("birthday");  //  ""   1980-09-09
            if(date==null || date.equals("")){
                user.setBirthday(null);
            }else{
                SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
                user.setBirthday(df.parse(date));
            }
            
            user.setEmail(e.attributeValue("email"));
            user.setId(e.attributeValue("id"));
            user.setNickname(e.attributeValue("nickname"));
            user.setPassword(e.attributeValue("password"));
            user.setUsername(e.attributeValue("username"));
            
            return user;
        
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    
    //查找注册的用户是否在数据库中存在
    public boolean find(String username){
        try{
            Document document = XmlUtils.getDocument();
            Element e = (Element) document.selectSingleNode("//user[@username='"+username+"']");
            if(e==null){
                return false;
            }
            return true;
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}



service层：BussinessServiceImpl .java

import com.dao.UserDao;
import com.dao.impl.UserDaoImpl;
import com.domain.User;
import com.service.BussinessService;
import com.utils.ServiceUtils;

import exception.UserExistException;

public class BussinessServiceImpl implements BussinessService{
    
    private UserDao dao = new UserDaoImpl();
    
    //提供注册业务逻辑
    public void register(User user) throws UserExistException{
        boolean b = dao.find(user.getUsername());
        if(b){
            throw new UserExistException(); 
        }else{
            user.setPassword(ServiceUtils.md5(user.getPassword()));
            dao.add(user);
        }
    }

    //登记业务逻辑
    public User login(String username,String password){  //aaa 123
        password = ServiceUtils.md5(password);
        return dao.find(username, password);
    }
}

web层：
LoginUIServlet.java:为用户提供注册界面

package com.web.UI;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//为用户提供登陆界面
public class LoginUIServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // "/"对服务器而言表示当前web应用
        request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response);
    }
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

 
RegisterUIServlet.java:为用户提供登陆界面

package com.web.UI;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//为用户提供登陆界面
public class LoginUIServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // "/"对服务器而言表示当前web应用
        request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response);
    }
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

RegisterForm.java:封装并校验注册表单提交的数据

package com.web.formbean;
import java.util.HashMap;
import java.util.Map;
import javax.print.attribute.standard.MediaSize.ISO;
import org.apache.commons.beanutils.locale.converters.DateLocaleConverter;

public class RegisterForm {
    private String username;
    private String password;
    private String password2;
    private String email;
    private String birthday;
    private String nickname;
    private String client_checkcode;
    public String getClient_checkcode() {
        return client_checkcode;
    }
    public void setClient_checkcode(String client_checkcode) {
        this.client_checkcode = client_checkcode;
    }
    public String getService_checkcode() {
        return service_checkcode;
    }
    public void setService_checkcode(String service_checkcode) {
        this.service_checkcode = service_checkcode;
    }

    private String service_checkcode;
    private Map errors = new HashMap();
    
    public Map getErrors() {
        return errors;
    }
    public void setErrors(Map errors) {
        this.errors = errors;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getPassword2() {
        return password2;
    }
    public void setPassword2(String password2) {
        this.password2 = password2;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    
    public String getBirthday() {
        return birthday;
    }
    public void setBirthday(String birthday) {
        this.birthday = birthday;
    }
    public String getNickname() {
        return nickname;
    }
    public void setNickname(String nickname) {
        this.nickname = nickname;
    }
    
    //用户名不能为空，并且要是3-8位字母
    //密码不能为空，并且是3-8位数字
    //确认密码不能为空，并且要和一次一致
    //电子邮箱不能为空，并且要是一个格式合法的邮箱
    //生日可以为空，不为空时，必须要是一个日期
    //昵称不可以为空，并且要是汉字
    public boolean validate(){
        boolean isOK = true;
        
        if(this.username==null || this.username.trim().equals("")){
            isOK = false;
            errors.put("username", "用户名不能为空！！");
        }else{
            if(!this.username.matches("[A-Za-z]{3,8}")){
                isOK = false;
                errors.put("username", "用户名必须要是3-8位字母！！");
            }
        }
        
        
        if(this.password==null || this.password.trim().equals("")){
            isOK = false;
            errors.put("password", "密码不能为空！！");
        }else{
            if(!this.password.matches("\d{3,8}")){
                isOK = false;
                errors.put("password", "密码必须要是3-8位数字！！");
            }
        }
        
        if(this.password2==null || this.password2.trim().equals("")){
            isOK = false;
            errors.put("password2", "确认密码不能为空！！");
        }else{
            if(!this.password.equals(this.password2)){
                isOK = false;
                errors.put("password2", "两次密码要一致！！");
            }
        }
        
        
        //电子邮箱不能为空，并且要是一个格式合法的邮箱
        if(this.email==null || this.email.trim().equals("")){
            isOK = false;
            errors.put("email", "邮箱不能为空！！");
        }else{
            // aaa@sina.com  aaa@sina.com.cn   aa_bb.cc@sina.com.cn
            //  \w+@\w+(\.\w+)+
            if(!this.email.matches("\w+@\w+(\.\w+)+")){
                isOK = false;
                errors.put("email", "邮箱格式不对！！！");
            }
        }
        
        ////生日可以为空，不为空时，必须要是一个日期
        if(this.birthday!=null && !this.birthday.trim().equals("")){
            try{
                DateLocaleConverter dlc = new DateLocaleConverter();
                dlc.convert(this.birthday, "yyyy-MM-dd");
            }catch (Exception e) {
                isOK = false;
                errors.put("birthday", "日期格式不对！！！");
            }
        }
        
        //昵称不可以为空，并且要是汉字
        if(this.nickname==null || this.nickname.trim().equals("")){
            isOK = false;
            errors.put("nickname", "昵称不能为空！！");
        }else{  //[^u4e00-u9fa5]*
            if(!this.nickname.matches("^([u4e00-u9fa5]+)$")){
                isOK = false;
                errors.put("nickname", "呢称必须是汉字！！！");
            }
        }
        
        //校验图片验证码
        if(client_checkcode==null || this.client_checkcode.trim().equals("")){
            isOK = false;
            errors.put("client_checkcode", "必须要输入认证码！！");
        }else{
            if(!this.client_checkcode.equals(this.service_checkcode)){
                isOK = false;
                errors.put("client_checkcode", "认证码错误！！！");
            }
        }
        return isOK;
    }
}

 

RegisterServlet.java：处理注册请求

package com.web.control;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.domain.User;
import com.service.impl.BussinessServiceImpl;
import com.utils.WebUtils;
import com.web.formbean.RegisterForm;
import exception.UserExistException;

//处理注册请求
public class RegisterServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        request.setCharacterEncoding("UTF-8");
        
        //1.对提交表单的字段进行合法性校验（把表单数据封装到formbean）
        RegisterForm form =  WebUtils.request2Bean(request, RegisterForm.class);
        String service_checkcode = (String) request.getSession().getAttribute("checkcode");
        form.setService_checkcode(service_checkcode);
        boolean b = form.validate();
        
        //2.如果校验失败，跳回到表单页面，回显校验失败信息
        if(!b){
            request.setAttribute("form", form);   
            request.getRequestDispatcher("/WEB-INF/jsp/register.jsp").forward(request, response);
            return;    
        }
        
        //3.如果校验成功，则调用service处理注册请求
        User user = new User();
        WebUtils.copyBean(form, user);
        user.setId(WebUtils.generateID());
        
        BussinessServiceImpl service = new BussinessServiceImpl();
        try {
            service.register(user);
            //6.如果serivce处理成功，跳转到网站的全局消息显示页面，为用户注册成功的消息
            request.setAttribute("message", "恭喜您，注册成功！！");
            request.getRequestDispatcher("/message.jsp").forward(request, response);
            return;
        } catch (UserExistException e) {
            //4.如果serivce处理不成功,并且不成功的原因，是因为注册用户已存在的话，则跳回到注册页面，显示注册用户已存在的消息
            form.getErrors().put("username", "注册的用户名已存在！！");
            request.setAttribute("form", form);
            request.getRequestDispatcher("/WEB-INF/jsp/register.jsp").forward(request, response);
            return;
        }catch (Exception e) {
            //5.如果serivce处理不成功,并且不成功的原因是其它问题的话，跳转到网站的全局消息显示页面，为用户显示友好错误消息
            e.printStackTrace();
            request.setAttribute("message", "服务器出现未知错误！！！");
            request.getRequestDispatcher("/message.jsp").forward(request, response);
            return;
        }
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

LoginServlet.java:处理登陆请求

package com.web.control;
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;
import com.domain.User;
import com.service.impl.BussinessServiceImpl;

public class LoginServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
            //获取用户名和密码
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        
        BussinessServiceImpl service = new BussinessServiceImpl();
        User user = service.login(username, password);
        
        if(user!=null){
            //登陆成功，跳转首页，在session保存登陆标记
            request.getSession().setAttribute("user", user);
            //重定向,应用程序名写法 request.getContextPath()/day09 项目部署后应用名称不一是day09
            response.sendRedirect(request.getContextPath()+"/index.jsp");
            return;
        }
        
        //登陆不成功，密码或者用户名错误
        request.setAttribute("message", "用户名或者密码错误");
        //跳转全局消息页面
        request.getRequestDispatcher("/message.jsp");
    }
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

ImageServlet.java：为注册页面提供验证码

package com.web.control;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//产生随机图片
public class ImageServlet extends HttpServlet {

    private static final int WIDTH = 120;
    private static final int HEIGHT = 25;
    
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        //1.在内存中创建一个图片
        BufferedImage image = new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB);
        
        //2.得到图片
        Graphics2D g = (Graphics2D) image.getGraphics();
        
        //3.设置背景色
        setBackground(g);
        
        //3.设置图片边框
        setBorder(g);
        
        //4.设置图片干扰线
        setRandomLine(g);
         
        //5.向图片上写数据
        String randomNum = drawRandomData2(g);
        
        //6.把图片写给客户机,再通知浏览器以图片方式打开数据,并且要通知浏览器不能缓存图片
        response.setHeader("Expires", "-1");
        response.setHeader("Cache-Control","no-cache");
        response.setHeader("Pragma","no-cache");
        
        response.setContentType("image/jpeg");
        ImageIO.write(image, "jpg", response.getOutputStream());
        
        //把产生的图片数据，在session中存一份
        request.getSession().setAttribute("checkcode", randomNum);
    }
    
    private void setBackground(Graphics g) {
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, WIDTH, HEIGHT);
    }

    private void setBorder(Graphics g) {
        g.setColor(Color.BLUE);
        g.drawRect(1, 1, WIDTH-2, HEIGHT-2);
    }
    
    private void setRandomLine(Graphics g) {
        g.setColor(Color.GREEN);
        for(int i=0;i<5;i++){
            int x1 = new Random().nextInt(WIDTH);
            int y1 = new Random().nextInt(HEIGHT); 
            int x2 = new Random().nextInt(WIDTH);
            int y2 = new Random().nextInt(HEIGHT); 
            g.drawLine(x1, y1, x2, y2);
        }
    }
    
    private String drawRandomData2(Graphics2D g) {
        
        StringBuffer sb = new StringBuffer();  // \ue40-\3
        //中文字符集编码
        String base = "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";
        
        for(int i=0;i<5;i++){
            int num = new Random().nextInt(base.length());
            sb.append(base.charAt(num));
        }
        
        String randomData = sb.toString();
        //设置数据的字体和颜色
        g.setColor(Color.RED);
        g.setFont(new Font("宋体",Font.BOLD,20));
        g.rotate(0.01);
        
        g.drawString(randomData, 0, 20);
        
        return randomData;
    }
    

    private void drawRandomData1(Graphics g) {
        
        StringBuffer sb = new StringBuffer();
        for(int i=0;i<5;i++){
            sb.append(new Random().nextInt(10) + " ");
        }
        String randomData = sb.toString();
        
        //设置数据的字体和颜色
        g.setColor(Color.RED);
        g.setFont(new Font("宋体",Font.BOLD,20));
        
        g.drawString(randomData, 10, 20);
    }
    

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

LogoutServlet.java:处理注销请求

package com.web.control;

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;
import javax.servlet.http.HttpSession;
/**
 * 处理注销请求
 * @author HaiHong
 *
 */
public class LogoutServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //获取session，false表示如果sesson不存在不用新创建一个session
        HttpSession session = request.getSession(false);
        if(session!=null){
            //移除登陆标记
            session.removeAttribute("user");
            //跳转全局消息页面,并控制浏览器3秒后跳转到首页,模仿meta标签
            request.setAttribute("message", "注销成功,浏览器将在3秒后跳转，如果没有跳转，你就点....！！<meta http-equiv='refresh' content='3;url="+request.getContextPath()+"/index.jsp'>");
            request.getRequestDispatcher("/message.jsp").forward(request, response);
            
        }
        
        
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
        
    }    

}

jsp页面：

  register.jsp：注册页面

　　

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>用户注册</title>
    <script type="text/javascript" src="${pageContext.request.contextPath }/js/ShowCalendar.js"></script>
    <style>
        body{
            background-color:#32a8cf;margin:0px;overflow: hidden;font-size:14px;color:#FFFFFF;
        }
        #main{
            margin-left:50px;margin-top:30px;
        }
        #notice{
            width:70%;line-height:25px;
        }
        #formtable{
            font-size:15px;
        }
        .td1{
            width:100px;
        }
        #formsubmit{
            width:300px;text-align:center;margin-top:15px;margin-left:50px;
        }
        .userinput {
            width:210px; height:25px; background-color:#FFFFFF; border:solid 1px #7dbad7; 
            font-size:16px;
        }    
        .btn{
            background-image:url(images/b2222.gif);
            background-position: center;
            font:bold 12px;
            width:80px;
            cursor:hand;
            height:25px;
            border-width:0;  /*按纽必须有此样式，才会出掉按纽背景*/
        }
    </style>
</head>

<body>
    <div id="header">
        <img src="images/head.gif">    
    </div>
        
    <div id="main">    
        <form action="${pageContext.request.contextPath }/servlet/RegisterServlet" method="post">
        <table id="formtable">
                <tr>
                    <td class="td1">登陆帐号：</td>
                    <td>
                        <input class="userinput" type="text" name="username" value="${form.username }">
                        <span class="message">${form.errors.username }</span>
                    </td>
                </tr>
                
                <tr>
                    <td></td>
                    <td></td>
                </tr>
                
                <tr>
                    <td class="td1">重复密码：</td>
                    <td>
                        <input class="userinput" type="password" name="password" value="${form.password }">
                        <span class="message">${form.errors.password }</span>
                    </td>
                </tr>
                
                <tr>
                    <td class="td1">确认密码：</td>
                    <td>
                        <input class="userinput" type="password" name="password2"  value="${form.password2 }">
                        <span class="message">${form.errors.password2 }</span>    
                    </td>
                </tr>
                
                <tr>
                    <td class="td1">电子邮箱：</td>
                    <td>
                        <input class="userinput" type="text" name="email"  value="${form.email }">
                        <span class="message">${form.errors.email }</span>
                    </td>
                </tr>
                
                <tr>
                    <td class="td1">生日：</td>
                    <td>
                        <input class="userinput" type="text" name="birthday" id="birthday" title="点击选择" onClick="showCalendar(this.id)" value="${form.birthday }">
                        <span class="message">${form.errors.birthday }</span>
                    </td>
                </tr>
                
                <tr>
                    <td class="td1">您的呢称：</td>
                    <td>
                        <input class="userinput" type="text" name="nickname" value="${form.nickname }">
                        <span class="message">${form.errors.nickname }</span>    
                    </td>
                </tr>
                
                <tr>
                    <td class="td1">图片认证：</td>
                    <td>
                        <input class="userinput" type="text" name="client_checkcode">
                        <span class="message">${form.errors.client_checkcode }</span>    
                        <br/>
                        <%--onclick="this.src+'?'+new Date().getTime()"
                            每次刷新在原来的地址上加一个日期，当刷新一定次数后图片会显示不出来，因为get请求后面的参数长度是有限的
                         --%>
                        <img src="${pageContext.request.contextPath }/servlet/ImageServlet" onclick="this.src=this.src+'?'+new Date().getTime()" height="25px" width="120px" alt="看不清" style="cursor: hand;">
                    </td>
                </tr>
        </table>
        <div id="formsubmit">
            <span><input class="btn" type="reset" name="reset" value="重 置"></span>
            &nbsp;&nbsp;
            <span><input class="btn" type="submit" name="submit" value="注 册"></span>
        </div>    
        </form>
    </div>    
    <div id="footer">
        
    </div>
</body>
</html>

  <img src="${pageContext.request.contextPath }/servlet/ImageServlet" onclick="this.src=this.src+'?'+new Date().getTime()" height="25px" width="120px" alt="看不清" style="cursor: hand;">

　　每次刷新在原来的地址上加一个日期，当刷新一定次数后图片会显示不出来，因为get请求后面的参数长度是有限的



login.jsp：登陆界面

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
      <head>
          <title>登陆界面</title>
    </head>
    
    <body>
        <div id="container">
            <div id="image">
                <div id="form">
                    <form action="${pageContext.request.contextPath }/servlet/LoginServlet" method="post">
                        <div class="input">
                            用户：<input class="inputtext" type="text" name="username" />
                        </div>
                        <div class="input">
                            密码：<input class="inputtext" type="password" name="password" />
                        </div>
                        <div id="btn">
                            <input class="btn" type="button" value="注册" onclick="window.location.href='register.html'" />
                            <input class="btn" type="submit" value="登陆" />
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </body>
</html>

index.jsp:首页

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>首页</title>
  </head>
  
  <body style="text-align: center;">
      
      <h1>xxxx网站</h1>
      <br/>
      
      <div style="text-align: right;">    
      <c:if test="${user!=null}">
          欢迎您：${user.nickname }  
          <a href="${pageContext.request.contextPath }/servlet/LogoutServlet">注销</a>
      </c:if>
      
      <c:if test="${user==null}">
        <a href="${pageContext.request.contextPath }/servlet/RegisterUIServlet">注册</a>
        <a href="${pageContext.request.contextPath }/servlet/LoginUIServlet">登陆</a>
    </c:if>
    </div>
    <hr>
  </body>
</html>

message.jsp:全局消息页面

<%@ 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>My JSP 'MyJsp.jsp' starting page</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>
     ${message }
  </body>
</html>

有些页面如登陆注册界面用户不能直接访问，由servlet跳转，把用户不能直接访问的页面放在WEB-INF目录下。

工具类：

　　ServiceUtils.java:对用户密码进行加密

package com.utils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import sun.misc.BASE64Encoder;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import sun.misc.BASE64Encoder;

//用户密码加密
public class ServiceUtils {
    public static String md5(String me){
        try {
            MessageDigest md = MessageDigest.getInstance("md5");
            byte md5[] = md.digest(me.getBytes());
            BASE64Encoder encoder = new BASE64Encoder();
            return encoder.encode(md5);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
    }
}

　　WebUtils.java:把表单数据封装到bean
　　 1 package com.utils;

import java.lang.reflect.InvocationTargetException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.beanutils.Converter;

public class WebUtils {
                                                               // RegisterForm.class
    public static <T> T request2Bean(HttpServletRequest request,Class<T> beanCalss){
        
        try{
            //1.创建要封装数据的bean
            T bean = beanCalss.newInstance();
            
            //2.把request中的数据整到bean中
            Enumeration  e = request.getParameterNames();
            while(e.hasMoreElements()){
                String name = (String) e.nextElement();   //username password email birthday
                String value = request.getParameter(name); //aaaa    123      aa@
                BeanUtils.setProperty(bean, name, value);
            }
            return bean;
        }catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    
    /*
    private String username;
    private String password;
    private String password2;
    private String email;
    private String birthday;
    private String nickname;
    private Map errors = new HashMap();
    
    private String id;
    private String username;
    private String password;
    private String email;
    private Date birthday;
    private String nickname;
         */
    
    public static void copyBean(Object src,Object dest){
        //注册日期转换器
        ConvertUtils.register(new Converter(){
            public Object convert(Class type, Object value) {
                if(value==null){
                    return null;
                }
                String str = (String) value;
                if(str.trim().equals("")){
                    return null;
                }
                SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
                try {
                    return df.parse(str);
                } catch (ParseException e) {
                    throw new RuntimeException(e);
                }
            }
        }, Date.class);
        try {
            BeanUtils.copyProperties(dest, src);
        } catch (Exception e) {
            throw new RuntimeException(e);
        } 
    }
    
    //产生全球唯一的id
    public static String generateID(){
        return UUID.randomUUID().toString();
    }

}

  XmlUtils.java：解析xml文件
　　

package com.utils;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class XmlUtils {
    
    private static String filepath;
    static{//通过类的加载器
        filepath = XmlUtils.class.getClassLoader().getResource("users.xml").getPath();
    }
    
    //解析xml
    public static Document getDocument() throws Exception{
        SAXReader reader = new SAXReader();
        Document document = reader.read(new File(filepath));
        return document;
    }
    
    //回写
    public static void reWrite(Document document) throws IOException{
        
        OutputFormat format = OutputFormat.createPrettyPrint();
        format.setEncoding("UTF-8");
        XMLWriter writer = new XMLWriter(new FileOutputStream(filepath), format );
        writer.write( document );
        writer.close();
    }
    
}

　　

　　xml文件：

　　users.xml:保存用户信息

　　　　

<?xml version="1.0" encoding="UTF-8"?>
<users>
     <user id="28323723727" username="aaa" password="123" email="aa@sina.com" birthday="1980-09-09" nickname="强子"/>
</users>