JavaWeb如何实现用户登录注册功能实例代码(基于Servlet+JSP+JavaBean模式)

package me.gacl.domain;
import java.io.Serializable;
import java.util.Date;
/**
* @author gacl
* 用户实体类
*/
public class User implements Serializable {
private static final long serialVersionUID = -L;
// 用户ID
private String id;
// 用户名
private String userName;
// 用户密码
private String userPwd;
// 用户邮箱
private String email;
// 用户生日
private Date birthday;
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 getUserPwd() {
return userPwd;
}
public void setUserPwd(String userPwd) {
this.userPwd = userPwd;
}
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;
}
}

package me.gacl.dao;
import me.gacl.domain.User;
public interface IUserDao {
/**
* 根据用户名和密码来查找用户
* @param userName
* @param userPwd
* @return 查到到的用户
*/
User find(String userName, String userPwd);
/**
* 添加用户
* @param user
*/
void add(User user);
/**根据用户名来查找用户
* @param userName
* @return 查到到的用户
*/
User find(String userName);
}

package me.gacl.dao.impl;
import java.text.SimpleDateFormat;
import org.domj.Document;
import org.domj.Element;
import me.gacl.dao.IUserDao;
import me.gacl.domain.User;
import me.gacl.util.XmlUtils;
/**
* IUserDao接口的实现类
* @author gacl
*/
public class UserDaoImpl implements IUserDao {
@Override
public User find(String userName, String userPwd) {
try{
Document document = XmlUtils.getDocument();
//使用XPath表达式来操作XML节点
Element e = (Element) document.selectSingleNode("//user[@userName='"+userName+"' and @userPwd='"+userPwd+"']");
if(e==null){
return null;
}
User user = new User();
user.setId(e.attributeValue("id"));
user.setEmail(e.attributeValue("email"));
user.setUserPwd(e.attributeValue("userPwd"));
user.setUserName(e.attributeValue("userName"));
String birth = e.attributeValue("birthday");
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
user.setBirthday(sdf.parse(birth));
return user;
}catch (Exception e) {
throw new RuntimeException(e);
}
}
@SuppressWarnings("deprecation")
@Override
public void add(User user) {
try{
Document document = XmlUtils.getDocument();
Element root = document.getRootElement();
Element user_node = root.addElement("user"); //创建user结点，并挂到root
user_node.setAttributeValue("id", user.getId());
user_node.setAttributeValue("userName", user.getUserName());
user_node.setAttributeValue("userPwd", user.getUserPwd());
user_node.setAttributeValue("email", user.getEmail());
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
user_node.setAttributeValue("birthday", sdf.format(user.getBirthday()));
XmlUtils.writeXml(document);
}catch (Exception e) {
throw new RuntimeException(e);
}
}
@Override
public User find(String userName) {
try{
Document document = XmlUtils.getDocument();
Element e = (Element) document.selectSingleNode("//user[@userName='"+userName+"']");
if(e==null){
return null;
}
User user = new User();
user.setId(e.attributeValue("id"));
user.setEmail(e.attributeValue("email"));
user.setUserPwd(e.attributeValue("userPwd"));
user.setUserName(e.attributeValue("userName"));
String birth = e.attributeValue("birthday");
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
user.setBirthday(sdf.parse(birth));
return user;
}catch (Exception e) {
throw new RuntimeException(e);
}
}
}

package me.gacl.service;
import me.gacl.domain.User;
import me.gacl.exception.UserExistException;
public interface IUserService {
/**
* 提供注册服务
* @param user
* @throws UserExistException
*/
void registerUser(User user) throws UserExistException;
/**
* 提供登录服务
* @param userName
* @param userPwd
* @return
*/
User loginUser(String userName, String userPwd);
}

package me.gacl.service.impl;
import me.gacl.dao.IUserDao;
import me.gacl.dao.impl.UserDaoImpl;
import me.gacl.domain.User;
import me.gacl.exception.UserExistException;
import me.gacl.service.IUserService;
public class UserServiceImpl implements IUserService {
private IUserDao userDao = new UserDaoImpl();
@Override
public void registerUser(User user) throws UserExistException {
if (userDao.find(user.getUserName())!=null) {
//checked exception 
//unchecked exception
//这里抛编译时异常的原因：是我想上一层程序处理这个异常，以给用户一个友好提示
throw new UserExistException("注册的用户名已存在！！！");
}
userDao.add(user);
}
@Override
public User loginUser(String userName, String userPwd) {
return userDao.find(userName, userPwd);
}
}

package me.gacl.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;
/**
* @author gacl
* 为用户提供注册的用户界面的Servlet
* RegisterUIServlet负责为用户输出注册界面
* 当用户访问RegisterUIServlet时，就跳转到WEB-INF/pages目录下的register.jsp页面
*/
public class RegisterUIServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.getRequestDispatcher("/WEB-INF/pages/register.jsp").forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}

<%@ page language="java" pageEncoding="UTF-"%>
<!DOCTYPE HTML>
<html>
<head>
<title>用户注册</title>
</head>
<body style="text-align: center;">
<form action="${pageContext.request.contextPath}/servlet/RegisterServlet" method="post">
<table width="%" border="">
<tr>
<td>用户名</td>
<td>
<input type="text" name="userName">
</td>
</tr>
<tr>
<td>密码</td>
<td>
<input type="password" name="userPwd">
</td>
</tr>
<tr>
<td>确认密码</td>
<td>
<input type="password" name="confirmPwd">
</td>
</tr>
<tr>
<td>邮箱</td>
<td>
<input type="text" name="email">
</td>
</tr>
<tr>
<td>生日</td>
<td>
<input type="text" name="birthday">
</td>
</tr>
<tr>
<td>
<input type="reset" value="清空">
</td>
<td>
<input type="submit" value="注册">
</td>
</tr>
</table>
</form>
</body>
</html>

package me.gacl.web.formbean;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.beanutils.locale.converters.DateLocaleConverter;
/**
* 封装的用户注册表单bean，用来接收register.jsp中的表单输入项的值
* RegisterFormBean中的属性与register.jsp中的表单输入项的name一一对应
* RegisterFormBean的职责除了负责接收register.jsp中的表单输入项的值之外还担任着校验表单输入项的值的合法性
* @author gacl
*
*/
public class RegisterFormBean {
//RegisterFormBean中的属性与register.jsp中的表单输入项的name一一对应
//<input type="text" name="userName"/>
private String userName;
//<input type="password" name="userPwd"/>
private String userPwd;
//<input type="password" name="confirmPwd"/>
private String confirmPwd;
//<input type="text" name="email"/>
private String email;
//<input type="text" name="birthday"/>
private String birthday;
/**
* 存储校验不通过时给用户的错误提示信息
*/
private Map<String, String> errors = new HashMap<String, String>();
public Map<String, String> getErrors() {
return errors;
}
public void setErrors(Map<String, String> errors) {
this.errors = errors;
}
/*
* validate方法负责校验表单输入项
* 表单输入项校验规则：
* private String userName; 用户名不能为空，并且要是-的字母 abcdABcd 
* private String userPwd; 密码不能为空，并且要是-的数字
* private String confirmPwd; 两次密码要一致
* private String email; 可以为空，不为空要是一个合法的邮箱 
* private String birthday; 可以为空，不为空时，要是一个合法的日期
*/
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]{,}")) {
isOk = false;
errors.put("userName", "用户名必须是-位的字母！！");
}
}
if (this.userPwd == null || this.userPwd.trim().equals("")) {
isOk = false;
errors.put("userPwd", "密码不能为空！！");
} else {
if (!this.userPwd.matches("\\d{,}")) {
isOk = false;
errors.put("userPwd", "密码必须是-位的数字！！");
}
}
// private String password; 两次密码要一致
if (this.confirmPwd != null) {
if (!this.confirmPwd.equals(this.userPwd)) {
isOk = false;
errors.put("confirmPwd", "两次密码不一致！！");
}
}
// private String email; 可以为空，不为空要是一个合法的邮箱
if (this.email != null && !this.email.trim().equals("")) {
if (!this.email.matches("\\w+@\\w+(\\.\\w+)+")) {
isOk = false;
errors.put("email", "邮箱不是一个合法邮箱！！");
}
}
// private String birthday; 可以为空，不为空时，要是一个合法的日期
if (this.birthday != null && !this.birthday.trim().equals("")) {
try {
DateLocaleConverter conver = new DateLocaleConverter();
conver.convert(this.birthday);
} catch (Exception e) {
isOk = false;
errors.put("birthday", "生日必须要是一个日期！！");
}
}
return isOk;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getUserPwd() {
return userPwd;
}
public void setUserPwd(String userPwd) {
this.userPwd = userPwd;
}
public String getConfirmPwd() {
return confirmPwd;
}
public void setConfirmPwd(String confirmPwd) {
this.confirmPwd = confirmPwd;
}
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;
}
}

package me.gacl.util;
import java.util.Enumeration;
import java.util.UUID;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.beanutils.BeanUtils;
/**
* @author gacl
* 把request对象中的请求参数封装到bean中
*/
public class WebUtils {
/**
* 将request对象转换成T对象
* @param request 
* @param clazz
* @return
*/
public static <T> T requestBean(HttpServletRequest request,Class<T> clazz){
try{
T bean = clazz.newInstance();
Enumeration<String> e = request.getParameterNames(); 
while(e.hasMoreElements()){
String name = (String) e.nextElement();
String value = request.getParameter(name);
BeanUtils.setProperty(bean, name, value);
}
return bean;
}catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* 生成UUID
* @return
*/
public static String makeId(){
return UUID.randomUUID().toString();
}
}

package me.gacl.web.controller;
import java.io.IOException;
import java.util.Date;
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 org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.beanutils.locale.converters.DateLocaleConverter;
import me.gacl.domain.User;
import me.gacl.exception.UserExistException;
import me.gacl.service.IUserService;
import me.gacl.service.impl.UserServiceImpl;
import me.gacl.util.WebUtils;
import me.gacl.web.formbean.RegisterFormBean;
/**
* 处理用户注册的Servlet
* @author gacl
*
*/
public class RegisterServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//将客户端提交的表单数据封装到RegisterFormBean对象中
RegisterFormBean formbean = WebUtils.requestBean(request,RegisterFormBean.class);
//校验用户注册填写的表单数据
if (formbean.validate() == false) {//如果校验失败
//将封装了用户填写的表单数据的formbean对象发送回register.jsp页面的form表单中进行显示
request.setAttribute("formbean", formbean);
//校验失败就说明是用户填写的表单数据有问题，那么就跳转回register.jsp
request.getRequestDispatcher("/WEB-INF/pages/register.jsp").forward(request, response);
return;
}
User user = new User();
try {
// 注册字符串到日期的转换器
ConvertUtils.register(new DateLocaleConverter(), Date.class);
BeanUtils.copyProperties(user, formbean);//把表单的数据填充到javabean中
user.setId(WebUtils.makeId());//设置用户的Id属性
IUserService service = new UserServiceImpl();
//调用service层提供的注册用户服务实现用户注册
service.registerUser(user);
String message = String.format(
"注册成功！！秒后为您自动跳到登录页面！！<meta http-equiv='refresh' content=';url=%s'/>", 
request.getContextPath()+"/servlet/LoginUIServlet");
request.setAttribute("message",message);
request.getRequestDispatcher("/message.jsp").forward(request,response);
} catch (UserExistException e) {
formbean.getErrors().put("userName", "注册用户已存在！！");
request.setAttribute("formbean", formbean);
request.getRequestDispatcher("/WEB-INF/pages/register.jsp").forward(request, response);
} catch (Exception e) {
e.printStackTrace(); // 在后台记录异常
request.setAttribute("message", "对不起，注册失败！！");
request.getRequestDispatcher("/message.jsp").forward(request,response);
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}

<%@ page language="java" pageEncoding="UTF-"%>
<!DOCTYPE HTML>
<html>
<head>
<title>用户注册</title>
</head>
<body style="text-align: center;">
<form action="${pageContext.request.contextPath}/servlet/RegisterServlet" method="post">
<table width="%" border="">
<tr>
<td>用户名</td>
<td>
<%--使用EL表达式${}提取存储在request对象中的formbean对象中封装的表单数据(formbean.userName)以及错误提示消息(formbean.errors.userName)--%>
<input type="text" name="userName" value="${formbean.userName}">${formbean.errors.userName}
</td>
</tr>
<tr>
<td>密码</td>
<td>
<input type="password" name="userPwd" value="${formbean.userPwd}">${formbean.errors.userPwd}
</td>
</tr>
<tr>
<td>确认密码</td>
<td>
<input type="password" name="confirmPwd" value="${formbean.confirmPwd}">${formbean.errors.confirmPwd}
</td>
</tr>
<tr>
<td>邮箱</td>
<td>
<input type="text" name="email" value="${formbean.email}">${formbean.errors.email}
</td>
</tr>
<tr>
<td>生日</td>
<td>
<input type="text" name="birthday" value="${formbean.birthday}">${formbean.errors.birthday}
</td>
</tr>
<tr>
<td>
<input type="reset" value="清空">
</td>
<td>
<input type="submit" value="注册">
</td>
</tr>
</table>
</form>
</body>
</html>

package me.gacl.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;
/**
* @author gacl
* LoginUIServlet负责为用户输出登陆界面
* 当用户访问LoginUIServlet时，就跳转到WEB-INF/pages目录下的login.jsp页面
*/
public class LoginUIServlet 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);
}
}

<%@ page language="java" pageEncoding="UTF-"%>
<!DOCTYPE HTML>
<html>
<head>
<title>用户登陆</title>
</head>
<body>
<form action="${pageContext.request.contextPath }/servlet/LoginServlet" method="post">
用户名：<input type="text" name="username"><br/>
密码：<input type="password" name="password"><br/>
<input type="submit" value="登陆">
</form>
</body>
</html>

package me.gacl.web.controller;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import me.gacl.domain.User;
import me.gacl.service.IUserService;
import me.gacl.service.impl.UserServiceImpl;
/**
* 处理用户登录的servlet
* @author gacl
*
*/
public class LoginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//获取用户填写的登录用户名
String username = request.getParameter("username");
//获取用户填写的登录密码
String password = request.getParameter("password");
IUserService service = new UserServiceImpl();
//用户登录
User user = service.loginUser(username, password);
if(user==null){
String message = String.format(
"对不起，用户名或密码有误！！请重新登录！秒后为您自动跳到登录页面！！<meta http-equiv='refresh' content=';url=%s'", 
request.getContextPath()+"/servlet/LoginUIServlet");
request.setAttribute("message",message);
request.getRequestDispatcher("/message.jsp").forward(request, response);
return;
}
//登录成功后，就将用户存储到session中
request.getSession().setAttribute("user", user);
String message = String.format(
"恭喜：%s,登陆成功！本页将在秒后跳到首页！！<meta http-equiv='refresh' content=';url=%s'", 
user.getUserName(),
request.getContextPath()+"/index.jsp");
request.setAttribute("message",message);
request.getRequestDispatcher("/message.jsp").forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}

package me.gacl.web.controller;
import java.io.IOException;
import java.text.MessageFormat;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LogoutServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//移除存储在session中的user对象，实现注销功能
request.getSession().removeAttribute("user");
//由于字符串中包含有单引号，在这种情况下使用MessageFormat.format方法拼接字符串时就会有问题
//MessageFormat.format方法只是把字符串中的单引号去掉，不会将内容填充到指定的占位符中
String tempStr = MessageFormat.format(
"注销成功！！秒后为您自动跳到登录页面！！<meta http-equiv='refresh' content=';url={}'/>", 
request.getContextPath()+"/servlet/LoginUIServlet");
System.out.println(tempStr);//输出结果：注销成功！！秒后为您自动跳到登录页面！！<meta http-equiv=refresh content=;url={}/>
System.out.println("---------------------------------------------------------");
/**
* 要想解决"如果要拼接的字符串包含有单引号，那么MessageFormat.format方法就只是把字符串中的单引号去掉，不会将内容填充到指定的占位符中"这个问题，
* 那么可以需要使用单引号引起来的字符串中使用个单引号引起来，例如："<meta http-equiv=''refresh'' content='';url={}''/>"
* 这样MessageFormat.format("<meta http-equiv=''refresh'' content='';url={}''/>","index.jsp")就可以正常返回
* <meta http-equiv=''refresh'' content='';url=index.jsp'/>
*/
String tempStr = MessageFormat.format(
"注销成功！！秒后为您自动跳到登录页面！！<meta http-equiv=''refresh'' content='';url={}''/>", 
request.getContextPath()+"/servlet/LoginUIServlet");
/**
* 输出结果：
* 注销成功！！秒后为您自动跳到登录页面！！
* <meta http-equiv='refresh' content=';url=/webmvcframework/servlet/LoginUIServlet'/>
*/
System.out.println(tempStr);
String message = String.format(
"注销成功！！秒后为您自动跳到登录页面！！<meta http-equiv='refresh' content=';url=%s'/>", 
request.getContextPath()+"/servlet/LoginUIServlet");
request.setAttribute("message",message);
request.getRequestDispatcher("/message.jsp").forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}

<%@ page language="java" pageEncoding="UTF-"%>
<%--为了避免在jsp页面中出现java代码，这里引入jstl标签库，利用jstl标签库提供的标签来做一些逻辑判断处理 --%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE HTML>
<html>
<head>
<title>首页</title>
<script type="text/javascript">
function doLogout(){
//访问LogoutServlet注销当前登录的用户
window.location.href="${pageContext.request.contextPath}/servlet/LogoutServlet";
}
</script>
</head>
<body>
<h>孤傲苍狼的网站</h>
<hr/>
<c:if test="${user==null}">
<a href="${pageContext.request.contextPath}/servlet/RegisterUIServlet" target="_blank">注册</a>
<a href="${pageContext.request.contextPath}/servlet/LoginUIServlet">登陆</a>
</c:if>
<c:if test="${user!=null}">
欢迎您：${user.userName}
<input type="button" value="退出登陆" onclick="doLogout()">
</c:if>
<hr/>
</body>
</html>