JavaMail學習筆記（七）帳號激活與忘記密碼 實例

 

一、帳戶激活

          在很多時候，在某些網站註冊一個用戶之後，網站會給這個用戶註冊時填寫的email地址發送一封帳戶激活郵件，這封郵件的內容就是一個激活帳戶的鏈接和一段簡短的文字描述，如果用戶沒有去郵箱將帳戶激活，可能在使用網站的某些功能時就會受到限制，比如不能發貼、下載資料、評論等限制。這麼做的原因應該是爲了保證帳戶的安全性和郵箱的有效性，以後網站如果有什麼活動、資訊或系統安全通知等，可以在第一時間通知到用戶。比如我在奇藝視頻網站註冊一個帳號之後，它就會往我註冊時填寫的郵箱中發一封帳戶激活的郵件，郵件中有一個激活的鏈接，點擊它就可以將你的帳戶激活。如下圖所示：

這個功能是怎麼做到的呢，其實實現也是很簡單的，說白了就是一個Update操作。

實現思路：當一個用戶註冊成功之後，系統向用戶註冊時提供的email地址發送一封郵件，郵件的內容是一個激活帳戶的鏈接和一段簡短的文字描述，這個鏈接的功能就是將這個帳戶的狀態修改成激活狀態。這個功能的重點在於如何生成這個激活帳戶的鏈接。直接可以聯想到的方法就是建一個Servlet，Servlet接收一個用戶名參數，Servlet拿到用戶名參數之後，到數據庫把這條記錄load出來，做一次update操作即可。但是這樣做會有風險，比如有人想在你的網站上搞破壞，註冊時他填的email地址就是亂填的，這個Email地址可能根本就收不到郵件（但符合email格式），註冊完成之後，然後在瀏覽器地址欄輸入網站之前發送的帳戶激活鏈接，並加上新註冊的用戶名參數，這樣一來就跳過了去郵箱激活的步聚，時間久了，庫中可能會留下許多無效的email地址和帳戶。爲了避免這個問題，解決方案是在用戶註冊成功之後，在發送激活帳戶的鏈接中加一個隨機碼，這個隨機碼是將用戶名和一個隨機數用md5加密後的一串16進制字符串，每次用戶在激活帳戶的時候，都驗證這個隨機碼是否和註冊時發送的一致，這樣就可以避免人爲的修改激活鏈接達到帳戶激活的功能。

二、忘記密碼

          當你在某網站註冊一個帳戶之後，發現這個帳戶很久沒用了，密碼也忘記了，如果還記得之前註冊時填寫的Email，那就可以向你的email中發一個重設密碼的鏈接，就可以重新設置你的密碼。大部份網站一般都提供了根據Email找回密碼的功能。實現此功能的思路：在登錄界面添加一個“忘記密碼“的鏈接，用戶點擊進去之後，輸入用戶名或Email，系統根據用戶名或Email找出用戶信息，並生成一個重新設置密碼的鏈接發送到用戶的郵箱中（生成鏈接的方式和生成帳戶激活鏈接的方式一樣），用戶在郵箱中點擊重設密碼的鏈接，根據提示進入密碼重設頁面，重新輸入新的密碼即可。

功能實現步聚（帳號激活）：

1、用戶註冊頁面

<form
action="${pageContext.request.contextPath}/register"
method="post">
    用戶名：<input
type="text"
name="userName"
value="${param.userName}"><span
class="error">${errors.userName}</span><br/>
    密碼：<input
type="password"
name="password"
><span
class="error">${errors.password}</span><br/>
    確認密碼：<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="註冊">
</form>

<form action="${pageContext.request.contextPath}/register" method="post">
	用戶名：<input type="text" name="userName" value="${param.userName}"><span class="error">${errors.userName}</span><br/>
	密碼：<input type="password" name="password" ><span class="error">${errors.password}</span><br/>
	確認密碼：<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="註冊">
</form>

2、處理註冊請求的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;

/**
* 用戶註冊
*/
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",
"用戶名不能爲空!");
        } else if (userName !=
null && userDao.findUserByName(userName) !=
null) {
            errors.put("userName",
"該用戶已註冊!");
        }

        if (password == null ||
"".equals(password)) {
            errors.put("password","密碼不能爲空!");
        } else if (password !=
null && password.length() < 3) {
            errors.put("password","密碼長度不能低於3位!");
        }

        if (password2 == null ||
"".equals(password2)) {
            errors.put("password2",
"確認密碼不能爲空!");
        } else if (password2 !=
null && !password2.equals(password)) {
            errors.put("password2",
"兩次輸入的密碼不一致!");
        }

        if (email == null ||
"".equals(email)) {
            errors.put("email",
"email不能爲空!");

        } 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格式不正確!");
        }

        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);

        // 註冊成功後,發送帳戶激活鏈接
        EmailUtils.sendAccountActivateEmail(user);

        // 註冊成功直接將當前用戶保存到session中
        request.getSession().setAttribute("user", user);
        request.getRequestDispatcher("/WEB-INF/pages/registerSuccess.jsp").forward(request,response);
    }
}

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;

/**
 * 用戶註冊
 */
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", "用戶名不能爲空!");
		} else if (userName != null && userDao.findUserByName(userName) != null) {
			errors.put("userName", "該用戶已註冊!");
		}
		
		if (password == null || "".equals(password)) {
			errors.put("password","密碼不能爲空!");
		} else if (password != null && password.length() < 3) {
			errors.put("password","密碼長度不能低於3位!");
		}
		
		if (password2 == null || "".equals(password2)) {
			errors.put("password2", "確認密碼不能爲空!");
		} else if (password2 != null && !password2.equals(password)) {
			errors.put("password2", "兩次輸入的密碼不一致!");
		}
		
		if (email == null || "".equals(email)) {
			errors.put("email", "email不能爲空!");
			
		} 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格式不正確!");
		}
		
		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);
		
		// 註冊成功後,發送帳戶激活鏈接
		EmailUtils.sendAccountActivateEmail(user);
		
		// 註冊成功直接將當前用戶保存到session中
		request.getSession().setAttribute("user", user);
		request.getRequestDispatcher("/WEB-INF/pages/registerSuccess.jsp").forward(request,response);
	}
}

3、激活帳戶的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;

/**
* 帳戶激活
*/
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("無效的用戶！");
        }
        UserDao userDao = UserDaoImpl.getInstance();
        User user = userDao.findUserById(id);// 得到要激活的帳戶
        user.setActivated(GenerateLinkUtils.verifyCheckcode(user, request));// 校驗驗證碼是否和註冊時發送的一致，以此設置是否激活該帳戶
        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);
    }
}

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;

/**
 * 帳戶激活
 */
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("無效的用戶！");
		}
		UserDao userDao = UserDaoImpl.getInstance();
		User user = userDao.findUserById(id);// 得到要激活的帳戶
		user.setActivated(GenerateLinkUtils.verifyCheckcode(user, request));// 校驗驗證碼是否和註冊時發送的一致，以此設置是否激活該帳戶
		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、操作用戶的DAO接口與實現類（UserDao和UserDaoImpl類）

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;
    }
}

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、發送Email的工具類（EmailUtils，用於發送帳戶激活鏈接和密碼重置鏈接）

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]";

    /**
     * 註冊成功後,向用戶發送帳戶激活鏈接的郵件
     * @param user 未激活的用戶
     */
    public static
void sendAccountActivateEmail(User user) {
        Session session = getSession();
        MimeMessage message = new MimeMessage(session);
        try {
            message.setSubject("帳戶激活郵件");
            message.setSentDate(new Date());
            message.setFrom(new InternetAddress(FROM));
            message.setRecipient(RecipientType.TO, 
new InternetAddress(user.getEmail()));
            message.setContent("<a href='" + GenerateLinkUtils.generateActivateLink(user)+"'>點擊激活帳戶</a>","text/html;charset=utf-8");
            // 發送郵件
            Transport.send(message);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 發送重設密碼鏈接的郵件
     */
    public static
void sendResetPasswordEmail(User user) {
        Session session = getSession();
        MimeMessage message = new MimeMessage(session);
        try {
            message.setSubject("找回您的帳戶與密碼");
            message.setSentDate(new Date());
            message.setFrom(new InternetAddress(FROM));
            message.setRecipient(RecipientType.TO, 
new InternetAddress(user.getEmail()));
            message.setContent("要使用新的密碼, 請使用以下鏈接啓用密碼:<br/><a href='" + GenerateLinkUtils.generateResetPwdLink(user) +"'>點擊重新設置密碼</a>","text/html;charset=utf-8");
            // 發送郵件
            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;
    }
}

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]";

	/**
	 * 註冊成功後,向用戶發送帳戶激活鏈接的郵件
	 * @param user 未激活的用戶
	 */
	public static void sendAccountActivateEmail(User user) {
		Session session = getSession();
		MimeMessage message = new MimeMessage(session);
		try {
			message.setSubject("帳戶激活郵件");
			message.setSentDate(new Date());
			message.setFrom(new InternetAddress(FROM));
			message.setRecipient(RecipientType.TO, new InternetAddress(user.getEmail()));
			message.setContent("<a href='" + GenerateLinkUtils.generateActivateLink(user)+"'>點擊激活帳戶</a>","text/html;charset=utf-8");
			// 發送郵件
			Transport.send(message);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	/**
	 * 發送重設密碼鏈接的郵件
	 */
	public static void sendResetPasswordEmail(User user) {
		Session session = getSession();
		MimeMessage message = new MimeMessage(session);
		try {
			message.setSubject("找回您的帳戶與密碼");
			message.setSentDate(new Date());
			message.setFrom(new InternetAddress(FROM));
			message.setRecipient(RecipientType.TO, new InternetAddress(user.getEmail()));
			message.setContent("要使用新的密碼, 請使用以下鏈接啓用密碼:<br/><a href='" + GenerateLinkUtils.generateResetPwdLink(user) +"'>點擊重新設置密碼</a>","text/html;charset=utf-8");
			// 發送郵件
			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、生成帳戶激活、密碼重設鏈接的工具類（GenerateLinkUtils）

package org.study.accountactivate.util;

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

import javax.servlet.ServletRequest;

import org.study.accountactivate.domail.User;

/**
* 生成帳戶激活、重新設置密碼的鏈接
*/
public class GenerateLinkUtils {

    private static
final String CHECK_CODE = "checkCode";

    /**
     * 生成帳戶激活鏈接
     */
    public static String generateActivateLink(User user) {
        return "http://localhost:8080/AccountActivate/activateAccount?id="
                + user.getId() + "&" + CHECK_CODE +
"=" + generateCheckcode(user);
    }

    /**
     * 生成重設密碼的鏈接
     */
    public static String generateResetPwdLink(User user) {
        return "http://localhost:8080/AccountActivate/resetPasswordUI?userName="
                + user.getUserName() + "&" + CHECK_CODE +
"=" + generateCheckcode(user);
    }

    /**
     * 生成驗證帳戶的MD5校驗碼
     * @param user  要激活的帳戶
     * @return 將用戶名和密碼組合後，通過md5加密後的16進制格式的字符串
     */
    public static String generateCheckcode(User user) {
        String userName = user.getUserName();
        String randomCode = user.getRandomCode();
        return md5(userName +
":" + randomCode);
    }

    /**
     * 驗證校驗碼是否和註冊時發送的驗證碼一致
     * @param user 要激活的帳戶
     * @param checkcode 註冊時發送的校驗碼
     * @return 如果一致返回true，否則返回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();
    }
}

package org.study.accountactivate.util;

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

import javax.servlet.ServletRequest;

import org.study.accountactivate.domail.User;

/**
 * 生成帳戶激活、重新設置密碼的鏈接
 */
public class GenerateLinkUtils {
	
	private static final String CHECK_CODE = "checkCode";
	
	/**
	 * 生成帳戶激活鏈接
	 */
	public static String generateActivateLink(User user) {
		return "http://localhost:8080/AccountActivate/activateAccount?id=" 
				+ user.getId() + "&" + CHECK_CODE + "=" + generateCheckcode(user);
	}
	
	/**
	 * 生成重設密碼的鏈接
	 */
	public static String generateResetPwdLink(User user) {
		return "http://localhost:8080/AccountActivate/resetPasswordUI?userName=" 
				+ user.getUserName() + "&" + CHECK_CODE + "=" + generateCheckcode(user);
	}
	
	/**
	 * 生成驗證帳戶的MD5校驗碼
	 * @param user  要激活的帳戶
	 * @return 將用戶名和密碼組合後，通過md5加密後的16進制格式的字符串
	 */
	public static String generateCheckcode(User user) {
		String userName = user.getUserName();
		String randomCode = user.getRandomCode();
		return md5(userName + ":" + randomCode);
	}
	
	/**
	 * 驗證校驗碼是否和註冊時發送的驗證碼一致
	 * @param user 要激活的帳戶
	 * @param checkcode 註冊時發送的校驗碼
	 * @return 如果一致返回true，否則返回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、實體類（User）

package org.study.accountactivate.domail;

public class User {
    // 編號
    private int id;
    // 用戶名
    private String userName;
    // 密碼
    private String password;
    // email
    private String email;
    // 是否激活
    private boolean activated;
    // 隨機碼(激活帳戶與生成重設密碼鏈接時使用)
    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;
    }

}

package org.study.accountactivate.domail;

public class User {
	// 編號
	private int id;
	// 用戶名
	private String userName;
	// 密碼
	private String password;
	// email
	private String email;
	// 是否激活
	private boolean activated;
	// 隨機碼(激活帳戶與生成重設密碼鏈接時使用)
	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;
	}

}

功能實現步驟（忘記密碼）：

1、登錄頁面

<form
action="${pageContext.request.contextPath}/login"
method="post">
    <span 
class="error"
style="display: block;">${errors.loginError}</span>
    用戶名：<input
type="text"
name="userName"
value="${param.userName}"><span
class="error">${errors.userName}</span><br/>
    密碼：<input
type="password"
name="password"><span
class="error">${errors.password}</span><br/>
    <input
type="submit"
value="登錄">
    <a 
href="${pageContext.request.contextPath}/forgotPwdUI">忘記密碼？</a>
    <a
href="${pageContext.request.contextPath}/registerUI">註冊</a>
</form>

<form action="${pageContext.request.contextPath}/login" method="post">
	<span class="error" style="display: block;">${errors.loginError}</span>
	用戶名：<input type="text" name="userName" value="${param.userName}"><span class="error">${errors.userName}</span><br/>
	密碼：<input type="password" name="password"><span class="error">${errors.password}</span><br/>
	<input type="submit" value="登錄"> 
	<a href="${pageContext.request.contextPath}/forgotPwdUI">忘記密碼？</a> 
	<a href="${pageContext.request.contextPath}/registerUI">註冊</a>
</form>

2、發送重設密碼申請的頁面

<form
action="${pageContext.request.contextPath}/forgotPwd"
method="post">
    <span 
style="color: red">${requestScope.sendMailMsg}</span>
    用戶名/郵箱：<input
type="text"
name="userNameOrEmail"
/><span
style="color: red">${requestScope.errorMsg}</span><br/>
    <input
type="submit"
value="提交"
/><a
href=""></a>
</form>

<form action="${pageContext.request.contextPath}/forgotPwd" method="post">
	<span style="color: red">${requestScope.sendMailMsg}</span>
	用戶名/郵箱：<input type="text" name="userNameOrEmail" /><span style="color: red">${requestScope.errorMsg}</span><br/>
	<input type="submit" value="提交" /><a href=""></a>
</form>

3、處理“發送重設密碼鏈接“請求的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;

/**
* 發送重設密碼申請的鏈接
*/
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;
        }

        // 發送重新設置密碼的鏈接
        EmailUtils.sendResetPasswordEmail(user);

        request.setAttribute("sendMailMsg",
"您的申請已提交成功，請查看您的"+user.getEmail()+"郵箱。");

        request.getRequestDispatcher("/WEB-INF/pages/forgotPwdSuccess.jsp").forward(request, response);
    }

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

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;

/**
 * 發送重設密碼申請的鏈接
 */
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;
		}
		
		// 發送重新設置密碼的鏈接
		EmailUtils.sendResetPasswordEmail(user);
		
		request.setAttribute("sendMailMsg", "您的申請已提交成功，請查看您的"+user.getEmail()+"郵箱。");
		
		request.getRequestDispatcher("/WEB-INF/pages/forgotPwdSuccess.jsp").forward(request, response);
	}

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

4、重新設置密碼的頁面

<form
action="${pageContext.request.contextPath}/resetPassword"
method="post">
    <span 
class="error"
style="display: block;">${errors.passwordError}</span>
    用戶名：<input
type="text"
name="userName"
value="${userName}"
readonly="readonly"/><br/>
    新密碼：<input
type="password"
name="newPassword"
/><span
class="error">${errors.newPassword }</span><br/>
    確認新密碼：<input
type="password"
name="newPassword2"/><span
class="error">${errors.newPassword2 }</span><br/>
    <input
type="submit"
value="修改"
/>
</form>

<form action="${pageContext.request.contextPath}/resetPassword" method="post">
	<span class="error" style="display: block;">${errors.passwordError}</span>
	用戶名：<input type="text" name="userName" value="${userName}" readonly="readonly"/><br/>
	新密碼：<input type="password" name="newPassword" /><span class="error">${errors.newPassword }</span><br/>
	確認新密碼：<input type="password" name="newPassword2"/><span class="error">${errors.newPassword2 }</span><br/>
	<input type="submit" value="修改" />
</form>

5、處理重新設置密碼請求的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;

/**
* 重新設置密碼
*/
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",
"新密碼不能爲空！");
        }

        if (newPassword2 ==
null || "".equals(newPassword2)) {
            errors.put("newPassword2",
"確認新密碼不能爲空！");
        }

        if (!newPassword.equals(newPassword2)) {
            errors.put("passwordError",
"兩次輸入的密碼不一致！");
        }

        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);
    }
}

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;

/**
 * 重新設置密碼
 */
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", "新密碼不能爲空！");
		}
		
		if (newPassword2 == null || "".equals(newPassword2)) {
			errors.put("newPassword2", "確認新密碼不能爲空！");
		}
		
		if (!newPassword.equals(newPassword2)) {
			errors.put("passwordError", "兩次輸入的密碼不一致！");
		}
		
		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);
	}
}

帳戶激活操作流程：

1）、註冊頁面

 

2）、註冊成功頁面

3）、帳戶未激活，登錄後的界面

4）、前往郵箱中激活帳戶

5）、激活成功

6）、帳戶已激活，登錄後的界面

忘記密碼操作流程：

1）、登錄頁面（點擊“忘記密碼”鏈接，進入重設密碼頁面）

2、重設密碼申請頁面（輸入用戶名或郵箱，點擊“提交”按鈕）

3、重設密碼申請成功頁面

4、郵箱中重設密碼的鏈接

5、重新設置密碼頁面

6、密碼重新設置成功頁面