01.注册+登录+注销

package lyyp.util;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
/**
 * XML解析？读取？写入？
 * @author Buddha
 *
 */
public class XmlUtils {
    private static String filename="DB.xml";
    
    public static Document getDocument()throws DocumentException{
        URL url =XmlUtils.class.getClassLoader().getResource(filename);
        String realpath =url.getPath();
        
        SAXReader reader =new SAXReader();
        return reader.read(new File(realpath));
    }
    
    public static void write2Xml(Document document) throws IOException{
        URL url =XmlUtils.class.getClassLoader().getResource(filename);
        String realpath=url.getPath();
        
        OutputFormat format=OutputFormat.createPrettyPrint();
        XMLWriter writer =new XMLWriter(new FileOutputStream(realpath),format);
        writer.write(document);
        writer.close();
    }
}

package lyyp.dao;
import lyyp.domain.User;
/**
 * @author Buddha
 *用户接口类
 */
public interface IUserDao {
    /** 按【/**加回车，为带参数注释段】
     * 根据用户名和密码来查找用户
     * @param userName
     * @param userPwd
     * @return 查找到的用户
     */
    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 查找到的用户
     */
    User find(String userName);
}

暂时不贴

package lyyp.exception;
/**
 * 自定义异常
 * 
 * @author Buddha
 *
 */
@SuppressWarnings("serial")//加上此代码，不出警告，否则需要UID=………………L
public class UserExistException extends Exception {
    public UserExistException() {
        super();
    }
    public UserExistException(String message, Throwable cause) {
        super(message, cause);
    }
    public UserExistException(String message){
        super(message);
    }
    public UserExistException(Throwable cause) {
        super(cause);
    }
}

package lyyp.service;
import lyyp.domain.User;
import lyyp.exception.UserExistException;
/**
 * service层对web层提供所有的业务服务 IUserService接口类
 * 
 * @author Buddha
 *
 */
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 lyyp.service.impl;
import lyyp.dao.IUserDao;
import lyyp.dao.impl.UserDaoImpl;
import lyyp.domain.User;
import lyyp.exception.UserExistException;
import lyyp.service.IUserService;
/**
 * IUserService接口的具体实现类
 * 
 * @author Buddha
 *
 */
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：让上一层处理这个异常，已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 lyyp.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 Buddha 
 * 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 
 */
@SuppressWarnings("serial")
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" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>用户注册</title>
</head>
<body style="text-align: center;">
<!-- <form action="${pageContext.request.contextPath}/servlet/RegisterServlet" method="post">指明表单提交后，交给RegisterServlet进行处理 -->
    <form
        action="${pageContext.request.contextPath}/servlet/RegisterServlet"
        method="post">
        <table>
            <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 lyyp.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,用来接受register.jsp中表单输入项的值
 * RegisterFormBean中的属性与register.jsp中的表单输入项的name一一对应
 * RegisterFormBean的职责除了负责接受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 Buddha
 *
 */
public class RegisterFormBean {
    // RegisterFormBean中的属性值与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;
    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3-8的字母
     * abcdABcd private String userPwd;密码不能为空，并且要是3-8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]{3,8}")) {
                isOk = false;
                errors.put("userName", "用户名必须是3-8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{3,8}")) {
                isOk = false;
                errors.put("userPwd", "密码必须是3-8位的数字");
            }
        }
        // private String password2; 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", "邮箱不合法");
            }
        }
        // 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", "日期不合法");
            }
        }
        return isOk;
    }

// 字段的get,set方法
    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 lyyp.util;
import java.util.Enumeration;
import java.util.UUID;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.beanutils.BeanUtils;
/**
 * 工具类，封装客户端提交的表单数据到formbean中
 * @author Buddha
 *
 */
public class WebUtils {
    /**
     * 将request对象装换成T对象
     * @param request
     * @param clazz
     * @return
     */
    public static <T> T request2Bean(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();
        }
    }
    /**
     * 生成
     * @return
     */
    public static String makeId(){
        return UUID.randomUUID().toString();
    }
    
}

package lyyp.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 lyyp.domain.User;
import lyyp.exception.UserExistException;
import lyyp.service.IUserService;
import lyyp.service.impl.UserServiceImpl;
import lyyp.util.WebUtils;
import lyyp.web.formbean.RegisterFormBean;
/**
 * 处理用户注册的Servlet
 * 
 * @author Buddha
 *
 */
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.request2Bean(request, RegisterFormBean.class);
        // 校验用户注册填写的表单
        if (formbean.validate() == false) {// 如果校验失败
            // 将封装了用户填写表单数据的formbean对象发送回register.jsp页面的form表单中进行显示
            request.setAttribute("formbean", formbean);
            // 校验石板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 messgae = String.format("注册成功！！3秒后为您自动跳转到登录页面<meta http-equiv=‘refresh‘content=‘3;url=%s‘/>",
                    request.getContextPath() + "/servlet/LoginUIServlet");
            request.setAttribute("message", messgae);
            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("messgae", "对不起，注册失败");
            request.getRequestDispatcher("/messags.jsp").forward(request, response);
        }
    }
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }
}

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>用户注册</title>
</head>
<body style="text-align: center;">
    <!-- <form action="${pageContext.request.contextPath}/servlet/RegisterServlet" method="post">指明表单提交后，交给RegisterServlet进行处理 -->
    <form
        action="${pageContext.request.contextPath}/servlet/RegisterServlet"
        method="post">
        <table>
            <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 }">${forambean.errors.userPwd }</td>
            </tr>
            <tr>
                <td>确认密码</td>
                <td><input type="password" name="confirmPwd"
                    value="${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>

 <!-- 注册的servlet -->
  <servlet>
  <servlet-name>RegisterUIServlet</servlet-name>
  <servlet-class>lyyp.web.UI.RegisterUIServlet</servlet-class>
  </servlet>
  
  <servlet>
  <servlet-name>RegisterServlet</servlet-name>
  <servlet-class>lyyp.web.controller.RegisterServlet</servlet-class>
  </servlet>
  
  <servlet-mapping>
  <servlet-name>RegisterUIServlet</servlet-name>
  <url-pattern>/servlet/RegisterUIServlet</url-pattern>
  </servlet-mapping>
  
  <servlet-mapping>
  <servlet-name>RegisterServlet</servlet-name>
  <url-pattern>/servlet/RegisterServelt</url-pattern>
  </servlet-mapping>

package lyyp.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 Buddha
 *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" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>用户登录</title>
</head>
<body>
<form action="${pageCpntext.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="登录"><br/>
</form>
</body>
</html>

package lyyp.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 lyyp.domain.User;
import lyyp.service.IUserService;
import lyyp.service.impl.UserServiceImpl;
/**
 * 处理用户登录的servlet
 * 
 * @author Buddha
 *
 */
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("用户名或密码有误，请重新登录！2秒后为您自动跳转到登录页面<meta http-equiv=‘refresh‘ content=‘2;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3秒后跳到首页！！<meta http-equiv=‘refresh‘ content=‘3;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);
    }
}

<!-- 登录的servlet -->
    <servlet>
        <servlet-name>LoginUIServlet</servlet-name>
        <servlet-class>lyyp.web.UI.LoginUIServlet</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>LoginServlet</servlet-name>
        <servlet-class>lyyp.web.controller.LoginServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>LoginUIServlet</servlet-name>
        <url-pattern>/servlet/LoginUIServlet</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>LoginServlet</servlet-name>
        <url-pattern>/servlet/LoginServlet</url-pattern>
    </servlet-mapping>

package lyyp.web.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
/**
 * 过滤器处理表单传到servlet的乱码问题
 * @author Buddha
 *
 */
public class CharacterEncodingFilter implements Filter{
    private String encoding =null;
    
    @Override
    public void init(FilterConfig filterConfig)throws ServletException{
        //encoding 在web.xml中指定
        this.encoding =filterConfig.getInitParameter("encoding");
    }
    
    @Override
    public void doFilter(ServletRequest request,ServletResponse response,FilterChain chain) throws IOException,ServletException{
        //解决表单提交时的中文乱码问题
        request.setCharacterEncoding(encoding);
        chain.doFilter(request, response);
    }
    @Override
    public void destroy(){
        
    }
}

<!-- filter过滤器 -->
  <filter>
    <filter-name>EncodingFilter</filter-name>
    <filter-class>lyyp.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>UTF-8</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>EncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>