Java Web 案例一 登录、注册功能实现

      实现用户登录和注册功能。项目分为 Web 层、业务逻辑层、数据访问层。

      将用户信息封装在 UserBean 对象中。用户信息有：username(String)、password(String)、nickname(String)、email(String)、birthday(Date)。

      在注册页面设计时，我们应考虑用户输入数据的合法性，所以我们将用户输入的表单数据封装在 FormBean 中，由于用户提交的数据都是以字符串的形式传递，因此 FormBean 中的所有对象都是 String 类型。在 FormBean 中还维护了一个 Map 对象，用以存放错误提示信息。如果用户输入的数据不合法，我们可以将错误信息作为 value 将表单项的名作为 key 存放在 Map 中，再以 request 属性的方式转发给注册页面，实现动态错误提示功能。为了防止机器人注册，我们还应该在注册页面中加入验证码。生成验证码的 Servlet 作为工具类存放在 utils 包中。服务器产生的验证码数据存放在服务器 session 对象中，用以用户提交表单时验证。为了防止 表单重复提交，我们在表单中还应该增加一个表单令牌，以隐藏域的形式存放。同样服务器的 session 对象中也应该增加这个属性。

       当用户提交注册请求的时候，我们利用 BeanUtils 的 populate 方法，将请求数据存放在 FormBean 中，如果验证合法，那么我们再将 FormBean 中的数据拷贝到 UserBean 中存储。在拷贝 Bean 对象时，我们利用 BeanUtils 的 copyBean 方法，将一个对象中的属性拷贝到另一个对象。注意，因为 FormBean 中的属性都是 String 类型，而 UserBean 中的生日是以 Date 类型存储，因此我们在拷贝属性时应该自定义一个转换器。在数据库中存储的用户密码应该是以 MD5 方式加密后的数据，我们在存储用户名密码时应该先用 MD5 运算后再存入数据库。

       用户登录页面提交数据到 LoginServlet 时，我们先将提交的密码数据进行  MD5 运算，然后与数据库中的密码进行比对。如果比对成功，则在 Session 域中存储用户信息，再跳转至首页。如果比对失败则将错误信息存放在 request 域中带给客户机进行提示。

 

       业务逻辑图：

 

         包层次关系：

 

 

 

cn.dk.domain

package cn.dk.domain;import java.util.Date;public class User {public User() {super();}public User(String username, String password, String nickname,String email, Date birthday) {super();this.username = username;this.password = password;this.nickname = nickname;this.email = email;this.birthday = birthday;}private String username;private String password;private String nickname;private String email;private Date birthday;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 getNickname() {return nickname;}public void setNickname(String nickname) {this.nickname = nickname;}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;}}

cn.dk.dao

package cn.dk.dao;import cn.dk.domain.User;public interface IUserDao {public void insertUser(User user);public boolean seacherUserByUsername(String username);public User searchUser(String username, String password);}

 

package cn.dk.dao.impl;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;import org.dom4j.Document;import org.dom4j.Element;import org.dom4j.Node;import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;import cn.dk.dao.IUserDao;import cn.dk.domain.User;import cn.dk.utils.XmlUtils;public class UserDaoImpl implements IUserDao {public void insertUser(User user) {// 获取xml文档对象Document document = XmlUtils.getDocument();// 获取文档根元素Element root = document.getRootElement();// 向根元素中增加子元素Element child = root.addElement("user");// 向子元素中增加用户名和密码属性child.addAttribute("username", user.getUsername());// 对密码加密String disgestPass = this.md5Disgest(user.getPassword());child.addAttribute("password", disgestPass);// 向子元素中增加昵称、email、生日属性child.addElement("nickname").addText(user.getNickname());child.addElement("email").addText(user.getEmail());if (user.getBirthday() != null) {SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");String birthday = format.format(user.getBirthday());child.addElement("birthday").addText(birthday);}// 保存xml到磁盘XmlUtils.saveXml(document);}public User searchUser(String username, String password) {// 获取xml文档对象Document document = XmlUtils.getDocument();// 获取文档根元素Element root = document.getRootElement();// 对密码进行md5运算String disgestPass = this.md5Disgest(password);// 匹配用户名和密码Element child = (Element) root.selectSingleNode("//user[@username='"+ username + "' and @password='" + disgestPass + "']");User user = null;if (child != null) {user = new User();user.setUsername(child.attributeValue("username"));user.setPassword(child.attributeValue("password"));user.setNickname(child.elementText("nickname"));user.setEmail(child.attributeValue("email"));String birthdayStr = child.attributeValue("birthday");if (birthdayStr != null) {SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");try {Date birthday = format.parse(child.attributeValue("birthday"));user.setBirthday(birthday);} catch (ParseException e) {throw new RuntimeException(e);}}}return user;}public boolean seacherUserByUsername(String username) {// 获取xml文档对象Document document = XmlUtils.getDocument();// 获取文档根元素Element root = document.getRootElement();// 匹配用户名Node selectSingleNode = root.selectSingleNode("//user[@username='"+ username + "']");if (selectSingleNode != null)return true;return false;}private String md5Disgest(String key) {try {MessageDigest disDigest = MessageDigest.getInstance("md5");byte[] digest = disDigest.digest(key.getBytes());String base = Base64.encode(digest);return base.substring(0, base.length() - 1);} catch (NoSuchAlgorithmException e) {throw new RuntimeException(e);}}}

cn.dk.service

package cn.dk.service;import cn.dk.domain.User;public interface IServiceDao {public void insertUser(User user);public boolean searchUserByUsername(String username);public User searchUser(String username, String password);}

package cn.dk.service.impl;import cn.dk.dao.impl.UserDaoImpl;import cn.dk.domain.User;import cn.dk.service.IServiceDao;public class ServiceImpl implements IServiceDao {private UserDaoImpl userDao = new UserDaoImpl();public void insertUser(User user) {userDao.insertUser(user);}public User searchUser(String username, String password) {return userDao.searchUser(username, password);}public boolean searchUserByUsername(String username) {return userDao.seacherUserByUsername(username);}}

cn.dk.web.control

package cn.dk.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;@SuppressWarnings("serial")public class LoginOut extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.getSession().removeAttribute("user");request.getRequestDispatcher("/index.jsp").forward(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

package cn.dk.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 cn.dk.domain.User;import cn.dk.service.impl.ServiceImpl;@SuppressWarnings("serial")public class LoginServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {ServiceImpl service = new ServiceImpl();String username = request.getParameter("username");String password = request.getParameter("password");System.out.println(password);User user = service.searchUser(username, password);if(user != null){response.sendRedirect(request.getContextPath() + "/index.jsp");}else{request.setAttribute("message", "用户名或密码错误");request.getRequestDispatcher("/WEB-INF/pages/login.jsp").forward(request, response);}}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

package cn.dk.web.control;import java.io.IOException;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.beanutils.BeanUtils;import cn.dk.domain.User;import cn.dk.service.impl.ServiceImpl;import cn.dk.utils.FormUtils;import cn.dk.utils.ServletUtils;@SuppressWarnings("serial")public class RegisterServlet extends HttpServlet {@SuppressWarnings("unchecked")public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.setCharacterEncoding("utf-8");String userFormId = request.getParameter("formid");String sessionFormId =  request.getSession().getAttribute("formid").toString();if (sessionFormId != null) {if (userFormId.equals(sessionFormId)) {request.getSession().removeAttribute("formid");Map<String, String> params = request.getParameterMap();FormUtils formBean = new FormUtils();try {BeanUtils.populate(formBean, params);boolean success = formBean.validate(request);if (!success) {request.setAttribute("error", formBean.getErrors());UUID randomUUID = UUID.randomUUID();request.setAttribute("formid", randomUUID.toString());request.getSession().setAttribute("formid",randomUUID.toString());request.getRequestDispatcher("/WEB-INF/pages/register.jsp").forward(request,response);} else {ServiceImpl service = new ServiceImpl();User user = new User();ServletUtils.copyBean(formBean, user);service.insertUser(user);request.getSession().setAttribute("user", user);request.setAttribute("message","注册成功！浏览器将在 3 秒内跳转到首页...<meta http-equiv='refresh' content='3;url="+ request.getContextPath()+ "/index.jsp'");request.getRequestDispatcher("/WEB-INF/pages/message.jsp").forward(request,response);}} catch (Exception e) {throw new RuntimeException(e);}}}}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

cn.dk.web.UI

package cn.dk.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;@SuppressWarnings("serial")public class Indx extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.getRequestDispatcher("/index.jsp").forward(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

package cn.dk.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;@SuppressWarnings("serial")public class LoginServletUI extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.getRequestDispatcher("/WEB-INF/pages/login.jsp").forward(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

 

package cn.dk.web.UI;import java.io.IOException;import java.util.UUID;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@SuppressWarnings("serial")public class RegisterServletUI extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {UUID randomUUID = UUID.randomUUID();request.setAttribute("formid", randomUUID.toString());request.getSession().setAttribute("formid", randomUUID.toString());request.getRequestDispatcher("/WEB-INF/pages/register.jsp").forward(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

cn.dk.utils

package cn.dk.utils;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;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;@SuppressWarnings("serial")public class CreateImgServlet extends HttpServlet {private static final int WIDTH = 130;private static final int HEIGHT = 30;public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {// 创建一张图片BufferedImage image = new BufferedImage(WIDTH, HEIGHT,BufferedImage.TYPE_INT_RGB);// 创建画板Graphics g = image.getGraphics();// 填充背景色this.fillBackcolor(g);// 画边框this.drawRect(g);// 画干扰线this.drawLine(g);// 画文字this.drawWrod(g, request);// 创建图片输出流response.setContentType("image/gif");response.setDateHeader("Expries", -1);response.setHeader("Pragma", "no-cache");response.setHeader("Cache-Control", "no-cache");ImageIO.write(image, "jpeg", response.getOutputStream());g.dispose();}private void drawWrod(Graphics g, HttpServletRequest request) {g.setColor(Color.YELLOW);g.setFont(new Font("黑体", Font.BOLD, 18));String words = "\u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50\u5f97\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66\u53ea\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1\u4e24\u7528\u5979\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b\u547d\u7ed9\u957f\u6c34\u51e0\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e\u5403\u505a\u53eb\u5f53\u4f4f\u542c\u9769\u6253\u5462\u771f\u5168\u624d\u56db\u5df2\u6240\u654c\u4e4b\u6700\u5149\u4ea7\u60c5\u8def\u5206\u603b\u6761\u767d\u8bdd\u4e1c\u5e2d\u6b21\u4eb2\u5982\u88ab\u82b1\u53e3\u653e\u513f\u5e38\u6c14\u4e94\u7b2c\u4f7f\u5199\u519b\u5427\u6587\u8fd0\u518d\u679c\u600e\u5b9a\u8bb8\u5feb\u660e\u884c\u56e0\u522b\u98de\u5916\u6811\u7269\u6d3b\u90e8\u95e8\u65e0\u5f80\u8239\u671b\u65b0\u5e26\u961f\u5148\u529b\u5b8c\u5374\u7ad9\u4ee3\u5458\u673a\u66f4\u4e5d\u60a8\u6bcf\u98ce\u7ea7\u8ddf\u7b11\u554a\u5b69\u4e07\u5c11\u76f4\u610f\u591c\u6bd4\u9636\u8fde\u8f66\u91cd\u4fbf\u6597\u9a6c\u54ea\u5316\u592a\u6307\u53d8\u793e\u4f3c\u58eb\u8005\u5e72\u77f3\u6ee1\u65e5\u51b3\u767e\u539f\u62ff\u7fa4\u7a76\u5404\u516d\u672c\u601d\u89e3\u7acb\u6cb3\u6751\u516b\u96be\u65e9\u8bba\u5417\u6839\u5171\u8ba9\u76f8\u7814\u4eca\u5176\u4e66\u5750\u63a5\u5e94\u5173\u4fe1\u89c9\u6b65\u53cd\u5904\u8bb0\u5c06\u5343\u627e\u4e89\u9886\u6216\u5e08\u7ed3\u5757\u8dd1\u8c01\u8349\u8d8a\u5b57\u52a0\u811a\u7d27\u7231\u7b49\u4e60\u9635\u6015\u6708\u9752\u534a\u706b\u6cd5\u9898\u5efa\u8d76\u4f4d\u5531\u6d77\u4e03\u5973\u4efb\u4ef6\u611f\u51c6\u5f20\u56e2\u5c4b\u79bb\u8272\u8138\u7247\u79d1\u5012\u775b\u5229\u4e16\u521a\u4e14\u7531\u9001\u5207\u661f\u5bfc\u665a\u8868\u591f\u6574\u8ba4\u54cd\u96ea\u6d41\u672a\u573a\u8be5\u5e76\u5e95\u6df1\u523b\u5e73\u4f1f\u5fd9\u63d0\u786e\u8fd1\u4eae\u8f7b\u8bb2\u519c\u53e4\u9ed1\u544a\u754c\u62c9\u540d\u5440\u571f\u6e05\u9633\u7167\u529e\u53f2\u6539\u5386\u8f6c\u753b\u9020\u5634\u6b64\u6cbb\u5317\u5fc5\u670d\u96e8\u7a7f\u5185\u8bc6\u9a8c\u4f20\u4e1a\u83dc\u722c\u7761\u5174\u5f62\u91cf\u54b1\u89c2\u82e6\u4f53\u4f17\u901a\u51b2\u5408\u7834\u53cb\u5ea6\u672f\u996d\u516c\u65c1\u623f\u6781\u5357\u67aa\u8bfb\u6c99\u5c81\u7ebf\u91ce\u575a\u7a7a\u6536\u7b97\u81f3\u653f\u57ce\u52b3\u843d\u94b1\u7279\u56f4\u5f1f\u80dc\u6559\u70ed\u5c55\u5305\u6b4c\u7c7b\u6e10\u5f3a\u6570\u4e61\u547c\u6027\u97f3\u7b54\u54e5\u9645\u65e7\u795e\u5ea7\u7ae0\u5e2e\u5566\u53d7\u7cfb\u4ee4\u8df3\u975e\u4f55\u725b\u53d6\u5165\u5cb8\u6562\u6389\u5ffd\u79cd\u88c5\u9876\u6025\u6797\u505c\u606f\u53e5\u533a\u8863\u822c\u62a5\u53f6\u538b\u6162\u53d4\u80cc\u7ec6";Random random = new Random();StringBuffer sb = new StringBuffer();int x = 15;for (int i = 0; i < 4; i++) {String word = words.charAt(random.nextInt(words.length())) + "";sb.append(word);g.drawString(word, x, 20);x += 30;}request.getSession().setAttribute("validateImg", sb.toString());}private void drawLine(Graphics g) {g.setColor(Color.RED);int x = 0;int _x = 0;int y = 0;int _y = 0;Random random = new Random();for (int i = 0; i < 5; i++) {x = random.nextInt(WIDTH);y = random.nextInt(HEIGHT);_x = random.nextInt(WIDTH);_y = random.nextInt(HEIGHT);g.drawLine(x, y, _x, _y);}}private void drawRect(Graphics g) {g.setColor(Color.BLUE);g.drawRect(1, 1, WIDTH - 2, HEIGHT - 2);}private void fillBackcolor(Graphics g) {g.setColor(Color.green);g.fillRect(0, 0, WIDTH, HEIGHT);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

 

package cn.dk.utils;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;import java.util.HashMap;import java.util.Map;import javax.servlet.http.HttpServletRequest;import cn.dk.service.impl.ServiceImpl;public class FormUtils {public FormUtils() {super();this.errors = new HashMap<String, String>();}private String username;private String password;private String rePassword;private String nickname;private String email;private String birthday;private String validateTxt;private Map<String, String> errors;public String getValidateTxt() {return validateTxt;}public void setValidateTxt(String validateTxt) {this.validateTxt = validateTxt;}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 getRePassword() {return rePassword;}public void setRePassword(String rePassword) {this.rePassword = rePassword;}public String getNickname() {return nickname;}public void setNickname(String nickname) {this.nickname = nickname;}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 Map<String, String> getErrors() {return errors;}public void setErrors(Map<String, String> errors) {this.errors = errors;}public boolean validate(HttpServletRequest request) {if (validateTxt == null || validateTxt.equals("")) {errors.put("validateTxt", "验证码不能为空");return false;}if (!request.getSession().getAttribute("validateImg").toString().equals(validateTxt)) {errors.put("validateTxt", "验证码不正确");return false;}if (username == null || username.trim().equals("")) {errors.put("username", "用户名不能为空");return false;}if (!username.matches("[a-zA-Z]{6,8}")) {errors.put("username", "用户名只能是6-8位字母");return false;}ServiceImpl service = new ServiceImpl();if (service.searchUserByUsername(username)) {errors.put("username", "用户名已存在");return false;}if (password == null || password.trim().equals("")) {errors.put("password", "密码不能为空");return false;}if (password.matches("\\.{6,8}")) {errors.put("password", "密码只能是6-8位字符");return false;}if (!password.equals(rePassword)) {errors.put("rePassword", "两次输入密码不一致");return false;}if (nickname == null || nickname.trim().equals("")) {errors.put("nickname", "昵称不能为空");return false;}if (!nickname.matches("[\u4e00-\u9fa5]+")) {errors.put("nickname", "昵称必须是中文");return false;}if (email == null || email.trim().equals("")) {errors.put("email", "邮箱不能为空");return false;}if (!email.matches("\\w+@\\w+\\.\\w+(\\.\\w+)?")) {errors.put("email", "邮箱格式不正确");return false;}if (birthday != "") {SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");try {Date parse = format.parse(birthday);if (parse == null) {errors.put("birthday", "出生日期格式不正确");return false;}} catch (ParseException e) {throw new RuntimeException(e);}}return true;}}

package cn.dk.utils;import java.text.SimpleDateFormat;import java.util.Date;import org.apache.commons.beanutils.BeanUtils;import org.apache.commons.beanutils.ConvertUtils;import org.apache.commons.beanutils.Converter;public class ServletUtils {public static void copyBean(Object src, Object des) { ConvertUtils.register(new Converter() { @SuppressWarnings("unchecked") public Object convert(Class arg0, Object type) { if (type == null) return null; String date = (String) type; if (date.trim().equals("")) return null; SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd"); Date birthday = null; try { birthday = format.parse(date); } catch (Exception e) { e.printStackTrace(); } return birthday; } }, Date.class); try { BeanUtils.copyProperties(des, src); } catch (Exception e) { throw new RuntimeException(e); }}}

package cn.dk.utils;import java.io.File;import java.io.FileOutputStream;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 {/** * 获取xml文档 *  * @return Dom4j 形式的Document文档对象 */public static Document getDocument() {// 获取xml文件路径String path = XmlUtils.class.getResource("/users.xml").getPath();// 获取xml读取器SAXReader reader = new SAXReader();try {// 解析xml文档，并返回Document文档模型return reader.read(new File(path));} catch (DocumentException e) {throw new RuntimeException(e);}}/** * 将文档对象写入磁盘 *  * @param document */public static void saveXml(Document document) {// 获取xml文件路径String path = XmlUtils.class.getResource("/users.xml").getPath();// 获取格式化输出流OutputFormat format = OutputFormat.createPrettyPrint();// 获取xml输出流XMLWriter writer;try {writer = new XMLWriter(new FileOutputStream(path), format);writer.write(document);} catch (Exception e) {throw new RuntimeException(e);}}}

XML

<?xml version="1.0" encoding="UTF-8"?><users><!--  <user username="driverking" password="123456"><nickname>文武</nickname><emial>[e-mail]</emial><birthday>1988-8-18</birthday></user>  --></users>

pages

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>用户登录</title>  </head>    <body>    <div align="center"><font color="green" face="微软雅黑" size="16">DK_用户登录</font></div><hr><form action="${pageContext.request.contextPath }/servlet/LoginServlet" method="post"><table><tr><td align="center" colspan="2">${requestScope.message }</td></tr><tr><td align="right">用户名：</td><td><input type="text" name="username" /></td></tr><tr><td align="right">密码：</td><td><input type="password" name="password" /></td></tr><tr><td align="right" colspan="2"><input type="submit" value="登录" /></td></tr></table></form>  </body></html>

message.jsp

 

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>系统消息</title>  </head>    <body>    <div align="center">    ${requestScope.message }    </div>  </body></html>

register.jsp

<%@ 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">function imgRefersh(img){img.src = img.src + "?" + new Date().getTime();}</script></head><body><div align="center"><font color="green" face="微软雅黑" size="16">DK_官网注册</font></div><hr><form action="${pageContext.request.contextPath }/servlet/RegisterServlet" method="post"><input type="hidden" name="formid" value="${sessionScope.formid }"><table width="60%" border="1" align="center"><tr><td align="right">用户名：</td><td><input type="text" name="username" value="${param.username }"/>${requestScope.error.username }</td></tr><tr><td align="right">密码：</td><td><input type="password" name="password" value="${param.password }"/>${requestScope.error.password }</td></tr><tr><td align="right">重复密码：</td><td><input type="password" name="rePassword" value="${param.rePassword }"/>${requestScope.error.rePassword }</td></tr><tr><td align="right">昵称：</td><td><input type="text" name="nickname" value="${param.nickname }"/>${requestScope.error.nickname }</td></tr><tr><td align="right">电子邮箱：</td><td><input type="text" name="email" value="${param.email }"/>${requestScope.error.email }</td></tr><tr><td align="right">生日：</td><td><input type="text" name="birthday" value="${param.birthday }"/>（yyy-mm-dd）${requestScope.error.birthday }</td></tr><tr><td align="right">验证码：</td><td><input type="text" name="validateTxt" ><img src="${pageContext.request.contextPath }/servlet/CreateImgServlet" alt="验证码" onclick="imgRefersh(this)" style="cursor: hand">${requestScope.error.validateTxt }</td></tr><tr><td align="center" colspan="2"><input type="submit" value="提交"/><input type="reset" value="重置"/></td></tr></table></form></body></html>

Index

<%@ 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>DK社区</title></head><body><div align="left"><font color="blue" size="18" face="微软雅黑">DriverKing_</font></div><div align="right"><c:choose><c:when test="${sessionScope.user == null}"><a href='${pageContext.request.contextPath }/servlet/LoginServletUI'>登录</a>  <a href='${pageContext.request.contextPath }/servlet/RegisterServletUI'>注册</a></c:when><c:otherwise>欢迎您：${sessionScope.user.nickname }  <a href=''>注销</a></c:otherwise></c:choose></div><hr></body></html>