一、帐户激活
在很多时候，在某些网站注册一个用户之后，网站会给这个用户注册时填写的email地址发送一封帐户激活邮件，这封邮件的内容就是一个激活帐户的链接和一段简短的文字描述，如果用户没有去邮箱将帐户激活，可能在使用网站的某些功能时就会受到限制，比如不能发贴、下载资料、评论等限制。这么做的原因应该是为了保证帐户的安全性和邮箱的有效性，以后网站如果有什么活动、资讯或系统安全通知等，可以在第一时间通知到用户。比如我在奇艺视频网站注册一个帐号之后，它就会往我注册时填写的邮箱中发一封帐户激活的邮件，邮件中有一个激活的链接，点击它就可以将你的帐户激活。如下图所示：
这个功能是怎么做到的呢，其实实现也是很简单的，说白了就是一个Update操作。
实现思路：当一个用户注册成功之后，系统向用户注册时提供的email地址发送一封邮件，邮件的内容是一个激活帐户的链接和一段简短的文字描述，这个链接的功能就是将这个帐户的状态修改成激活状态。这个功能的重点在于如何生成这个激活帐户的链接。直接可以联想到的方法就是建一个Servlet，Servlet接收一个用户名参数，Servlet拿到用户名参数之后，到数据库把这条记录load出来，做一次update操作即可。但是这样做会有风险，比如有人想在你的网站上搞破坏，注册时他填的email地址就是乱填的，这个Email地址可能根本就收不到邮件（但符合email格式），注册完成之后，然后在浏览器地址栏输入网站之前发送的帐户激活链接，并加上新注册的用户名参数，这样一来就跳过了去邮箱激活的步聚，时间久了，库中可能会留下许多无效的email地址和帐户。为了避免这个问题，解决方案是在用户注册成功之后，在发送激活帐户的链接中加一个随机码，这个随机码是将用户名和一个随机数用md5加密后的一串16进制字符串，每次用户在激活帐户的时候，都验证这个随机码是否和注册时发送的一致，这样就可以避免人为的修改激活链接达到帐户激活的功能。
二、忘记密码
当你在某网站注册一个帐户之后，发现这个帐户很久没用了，密码也忘记了，如果还记得之前注册时填写的Email，那就可以向你的email中发一个重设密码的链接，就可以重新设置你的密码。大部份网站一般都提供了根据Email找回密码的功能。实现此功能的思路：在登录界面添加一个“忘记密码“的链接，用户点击进去之后，输入用户名或Email，系统根据用户名或Email找出用户信息，并生成一个重新设置密码的链接发送到用户的邮箱中（生成链接的方式和生成帐户激活链接的方式一样），用户在邮箱中点击重设密码的链接，根据提示进入密码重设页面，重新输入新的密码即可。
功能实现步聚（帐号激活）：
1、用户注册页面
<form action="${pageContext.request.contextPath}/register" method="post">
用户名：<input type="text" name="userName" value="${param.userName}"><span class="error">${errors.userName}</span><br/>
密码：<input type="password" name="password" ><span class="error">${errors.password}</span><br/>
确认密码：<input type="password" name="password2"><span class="error">${errors.password2}</span><br/>
email：<input type="text" name="email" value="${param.email}"><span class="error">${errors.email}</span><br/>
<input type="submit" value="注册">
</form>
2、处理注册请求的Servlet（RegisterServlet）
package org.study.accountactivate.web.servlet;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.study.accountactivate.dao.UserDao;
import org.study.accountactivate.dao.impl.UserDaoImpl;
import org.study.accountactivate.domail.User;
import org.study.accountactivate.util.EmailUtils;
/**
* 用户注册
*/
public class RegisterServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private UserDao userDao = UserDaoImpl.getInstance();
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String userName = request.getParameter("userName");
String password = request.getParameter("password");
String password2 = request.getParameter("password2");
String email = request.getParameter("email");
Map<String, String> errors = new HashMap<String,String>();
if (userName == null || "".equals(userName)) {
errors.put("userName", "用户名不能为空!");
} else if (userName != null && userDao.findUserByName(userName) != null) {
errors.put("userName", "该用户已注册!");
}
if (password == null || "".equals(password)) {
errors.put("password","密码不能为空!");
} else if (password != null && password.length() < 3) {
errors.put("password","密码长度不能低于3位!");
}
if (password2 == null || "".equals(password2)) {
errors.put("password2", "确认密码不能为空!");
} else if (password2 != null && !password2.equals(password)) {
errors.put("password2", "两次输入的密码不一致!");
}
if (email == null || "".equals(email)) {
errors.put("email", "email不能为空!");
} else if (email != null && !email.matches("[0-9a-zA-Z_-]+@[0-9a-zA-Z_-]+\\.[0-9a-zA-Z_-]+(\\.[0-9a-zA-Z_-])*")) {
errors.put("email", "email格式不正确!");
}
if (!errors.isEmpty()) {
request.setAttribute("errors", errors);
request.getRequestDispatcher("/registerUI").forward(request, response);
return;
}
User user = new User();
user.setUserName(userName);
user.setPassword(password);
user.setEmail(email);
user.setActivated(false);
userDao.addUser(user);
// 注册成功后,发送帐户激活链接
EmailUtils.sendAccountActivateEmail(user);
// 注册成功直接将当前用户保存到session中
request.getSession().setAttribute("user", user);
request.getRequestDispatcher("/WEB-INF/pages/registerSuccess.jsp").forward(request,response);
}
}
3、激活帐户的Servlet（ActivateAccountServle）
package org.study.accountactivate.web.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.study.accountactivate.dao.UserDao;
import org.study.accountactivate.dao.impl.UserDaoImpl;
import org.study.accountactivate.domail.User;
import org.study.accountactivate.util.GenerateLinkUtils;
/**
* 帐户激活
*/
public class ActivateAccountServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String idValue = request.getParameter("id");
int id = -1;
try {
id = Integer.parseInt(idValue);
} catch (NumberFormatException e) {
throw new RuntimeException("无效的用户！");
}
UserDao userDao = UserDaoImpl.getInstance();
User user = userDao.findUserById(id);// 得到要激活的帐户
user.setActivated(GenerateLinkUtils.verifyCheckcode(user, request));// 校验验证码是否和注册时发送的一致，以此设置是否激活该帐户
userDao.updateUser(user);
request.getSession().setAttribute("user", user);
request.getRequestDispatcher("/accountActivateUI").forward(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
4、操作用户的DAO接口与实现类（UserDao和UserDaoImpl类）
package org.study.accountactivate.dao;
import org.study.accountactivate.domail.User;
public interface UserDao {
void addUser(User user);
void updateUser(User user);
User findUserById(int id);
User findUserByName(String userName);
User findUserByNameOrEmail(String nameOrEmail);
}
package org.study.accountactivate.dao.impl;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.UUID;
import org.study.accountactivate.dao.UserDao;
import org.study.accountactivate.domail.User;
public class UserDaoImpl implements UserDao {
private static UserDaoImpl instance = new UserDaoImpl();
private UserDaoImpl() {}
public static UserDaoImpl getInstance() {
return instance;
}
Map<Integer,User> users = new HashMap<Integer, User>();
int nextId = 1;
@Override
public void addUser(User user) {
user.setId(nextId++);
user.setRandomCode(UUID.randomUUID().toString());
users.put(user.getId(), user);
}
@Override
public void updateUser(User user) {
users.put(user.getId(), user);
}
@Override
public User findUserById(int id) {
return users.get(id);
}
@Override
public User findUserByName(String userName) {
Collection<User> userValues = users.values();
for (Iterator<User> iterator = userValues.iterator();iterator.hasNext();) {
User user = iterator.next();
if (user.getUserName().equals(userName)) {
return user;
}
}
return null;
}
@Override
public User findUserByNameOrEmail(String nameOrEmail) {
Collection<User> userValues = users.values();
for(Iterator<User> iterator = userValues.iterator();iterator.hasNext();) {
User user = iterator.next();
if (user.getEmail().equals(nameOrEmail) || user.getUserName().equals(nameOrEmail)) {
return user;
}
}
return null;
}
}
5、发送Email的工具类（EmailUtils，用于发送帐户激活链接和密码重置链接）
package org.study.accountactivate.util;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.Properties;
import javax.mail.Authenticator;
import javax.mail.Message.RecipientType;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import org.study.accountactivate.domail.User;
public class EmailUtils {
private static final String FROM = "[email protected]";
/**
* 注册成功后,向用户发送帐户激活链接的邮件
* @param user 未激活的用户
*/
public static void sendAccountActivateEmail(User user) {
Session session = getSession();
MimeMessage message = new MimeMessage(session);
try {
message.setSubject("帐户激活邮件");
message.setSentDate(new Date());
message.setFrom(new InternetAddress(FROM));
message.setRecipient(RecipientType.TO, new InternetAddress(user.getEmail()));
message.setContent("<a href='" + GenerateLinkUtils.generateActivateLink(user)+"'>点击激活帐户</a>","text/html;charset=utf-8");
// 发送邮件
Transport.send(message);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 发送重设密码链接的邮件
*/
public static void sendResetPasswordEmail(User user) {
Session session = getSession();
MimeMessage message = new MimeMessage(session);
try {
message.setSubject("找回您的帐户与密码");
message.setSentDate(new Date());
message.setFrom(new InternetAddress(FROM));
message.setRecipient(RecipientType.TO, new InternetAddress(user.getEmail()));
message.setContent("要使用新的密码, 请使用以下链接启用密码:<br/><a href='" + GenerateLinkUtils.generateResetPwdLink(user) +"'>点击重新设置密码</a>","text/html;charset=utf-8");
// 发送邮件
Transport.send(message);
} catch (Exception e) {
e.printStackTrace();
}
}
public static Session getSession() {
Properties props = new Properties();
props.setProperty("mail.transport.protocol", "smtp");
props.setProperty("mail.smtp.host", "smtp.163.com");
props.setProperty("mail.smtp.port", "25");
props.setProperty("mail.smtp.auth", "true");
Session session = Session.getInstance(props, new Authenticator() {
@Override
protected PasswordAuthentication getPasswordAuthentication() {
String password = null;
InputStream is = EmailUtils.class.getResourceAsStream("password.dat");
byte[] b = new byte[1024];
try {
int len = is.read(b);
password = new String(b,0,len);
} catch (IOException e) {
e.printStackTrace();
}
return new PasswordAuthentication(FROM, password);
}
});
return session;
}
}
6、生成帐户激活、密码重设链接的工具类（GenerateLinkUtils）
package org.study.accountactivate.util;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import javax.servlet.ServletRequest;
import org.study.accountactivate.domail.User;
/**
* 生成帐户激活、重新设置密码的链接
*/
public class GenerateLinkUtils {
private static final String CHECK_CODE = "checkCode";
/**
* 生成帐户激活链接
*/
public static String generateActivateLink(User user) {
return "http://localhost:8080/AccountActivate/activateAccount?id="
+ user.getId() + "&" + CHECK_CODE + "=" + generateCheckcode(user);
}
/**
* 生成重设密码的链接
*/
public static String generateResetPwdLink(User user) {
return "http://localhost:8080/AccountActivate/resetPasswordUI?userName="
+ user.getUserName() + "&" + CHECK_CODE + "=" + generateCheckcode(user);
}
/**
* 生成验证帐户的MD5校验码
* @param user 要激活的帐户
* @return 将用户名和密码组合后，通过md5加密后的16进制格式的字符串
*/
public static String generateCheckcode(User user) {
String userName = user.getUserName();
String randomCode = user.getRandomCode();
return md5(userName + ":" + randomCode);
}
/**
* 验证校验码是否和注册时发送的验证码一致
* @param user 要激活的帐户
* @param checkcode 注册时发送的校验码
* @return 如果一致返回true，否则返回false
*/
public static boolean verifyCheckcode(User user,ServletRequest request) {
String checkCode = request.getParameter(CHECK_CODE);
return generateCheckcode(user).equals(checkCode);
}
private static String md5(String string) {
MessageDigest md = null;
try {
md = MessageDigest.getInstance("md5");
md.update(string.getBytes());
byte[] md5Bytes = md.digest();
return bytes2Hex(md5Bytes);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return null;
}
private static String bytes2Hex(byte[] byteArray)
{
StringBuffer strBuf = new StringBuffer();
for (int i = 0; i < byteArray.length; i++)
{
if(byteArray[i] >= 0 && byteArray[i] < 16)
{
strBuf.append("0");
}
strBuf.append(Integer.toHexString(byteArray[i] & 0xFF));
}
return strBuf.toString();
}
}
7、实体类（User）
package org.study.accountactivate.domail;
public class User {
// 编号
private int id;
// 用户名
private String userName;
// 密码
private String password;
// email
private String email;
// 是否激活
private boolean activated;
// 随机码(激活帐户与生成重设密码链接时使用)
private String randomCode;
public int getId() {
return id;
}
public void setId(int 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 boolean isActivated() {
return activated;
}
public void setActivated(boolean activated) {
this.activated = activated;
}
public String getRandomCode() {
return randomCode;
}
public void setRandomCode(String randomCode) {
this.randomCode = randomCode;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
功能实现步骤（忘记密码）：
1、登录页面
<form action="${pageContext.request.contextPath}/login" method="post">
<span class="error" style="display: block;">${errors.loginError}</span>
用户名：<input type="text" name="userName" value="${param.userName}"><span class="error">${errors.userName}</span><br/>
密码：<input type="password" name="password"><span class="error">${errors.password}</span><br/>
<input type="submit" value="登录">
<a href="${pageContext.request.contextPath}/forgotPwdUI">忘记密码？</a>
<a href="${pageContext.request.contextPath}/registerUI">注册</a>
</form>
2、发送重设密码申请的页面
<form action="${pageContext.request.contextPath}/forgotPwd" method="post">
<span style="color: red">${requestScope.sendMailMsg}</span>
用户名/邮箱：<input type="text" name="userNameOrEmail" /><span style="color: red">${requestScope.errorMsg}</span><br/>
<input type="submit" value="提交" /><a href=""></a>
</form>
3、处理“发送重设密码链接“请求的Servlet（ForgotPwdServlet）
package org.study.accountactivate.web.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.study.accountactivate.dao.UserDao;
import org.study.accountactivate.dao.impl.UserDaoImpl;
import org.study.accountactivate.domail.User;
import org.study.accountactivate.util.EmailUtils;
/**
* 发送重设密码申请的链接
*/
public class ForgotPwdServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String userNameOrEmail = request.getParameter("userNameOrEmail");
UserDao userDao = UserDaoImpl.getInstance();
User user = userDao.findUserByNameOrEmail(userNameOrEmail);
if (user == null) {
request.setAttribute("errorMsg", userNameOrEmail + "，不存在！");
request.getRequestDispatcher("/forgotPwdUI").forward(request, response);
return;
}
// 发送重新设置密码的链接
EmailUtils.sendResetPasswordEmail(user);
request.setAttribute("sendMailMsg", "您的申请已提交成功，请查看您的"+user.getEmail()+"邮箱。");
request.getRequestDispatcher("/WEB-INF/pages/forgotPwdSuccess.jsp").forward(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
4、重新设置密码的页面
<form action="${pageContext.request.contextPath}/resetPassword" method="post">
<span class="error" style="display: block;">${errors.passwordError}</span>
用户名：<input type="text" name="userName" value="${userName}" readonly="readonly"/><br/>
新密码：<input type="password" name="newPassword" /><span class="error">${errors.newPassword }</span><br/>
确认新密码：<input type="password" name="newPassword2"/><span class="error">${errors.newPassword2 }</span><br/>
<input type="submit" value="修改" />
</form>
5、处理重新设置密码请求的Servlet（ResetPasswordServlet）
package org.study.accountactivate.web.servlet;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.study.accountactivate.dao.UserDao;
import org.study.accountactivate.dao.impl.UserDaoImpl;
import org.study.accountactivate.domail.User;
/**
* 重新设置密码
*/
public class ResetPasswordServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String userName = request.getParameter("userName");
String newPassword = request.getParameter("newPassword");
String newPassword2 = request.getParameter("newPassword2");
Map<String,String> errors = new HashMap<String, String>();
if (newPassword == null || "".equals(newPassword)) {
errors.put("newPassword", "新密码不能为空！");
}
if (newPassword2 == null || "".equals(newPassword2)) {
errors.put("newPassword2", "确认新密码不能为空！");
}
if (!newPassword.equals(newPassword2)) {
errors.put("passwordError", "两次输入的密码不一致！");
}
if (!errors.isEmpty()) {
request.setAttribute("errors", errors);
request.getRequestDispatcher("/resetPasswordUI?userName=" + userName).forward(request, response);
return;
}
UserDao userDao = UserDaoImpl.getInstance();
User user = userDao.findUserByName(userName);
user.setPassword(newPassword);
request.getRequestDispatcher("/WEB-INF/pages/resetPasswordSuccess.jsp").forward(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
帐户激活操作流程：
1）、注册页面
2）、注册成功页面
3）、帐户未激活，登录后的界面
4）、前往邮箱中激活帐户
5）、激活成功
6）、帐户已激活，登录后的界面
忘记密码操作流程：
1）、登录页面（点击“忘记密码”链接，进入重设密码页面）
2、重设密码申请页面（输入用户名或邮箱，点击“提交”按钮）
3、重设密码申请成功页面
4、邮箱中重设密码的链接
5、重新设置密码页面
6、密码重新设置成功页面
转自：http://blog.csdn.net/xyang81/article/details/7727141#comments