用户注册和登录案例

用户注册和登录案例

1.功能分析

1、技术架构：三层架构（表现层MVC：M：model V:View C：Controller）

2、要求：JSP中不能出现一行java脚本或java表达式。除了指令<%@%>,其余地方不能有<%%>

3、数据库：临时使用xml。解析使用Dom4j

4、必须知道要干什么？



5、开发步骤：

a、建立工程，搭建开发环境（拷贝jar包、建立配置文件）

dom4j.jar

jaxen.jar

commons-beanutils.jar

commons-logging.jar

standard.jar

jstl.jar

b、建立类所用的包

cn.itcast.domain:放JavaBean 弄出数据库

cn.itcast.dao:放Dao接口

cn.itcast.dao.impl:放Dao接口的实现

cn.itcast.servcie:业务接口

cn.itcast.service.impl:业务接口实现

cn.itcast.web.controller:Servlet控制器

//WEB-INF/pages:用户无法直接访问（只能靠转发）

把握两点：

1、domain中的javabean

2、业务接口

知识点：用户输入数据的验证

1、客户端验证：使用js代码。减轻服务器的负担

2、服务器端验证：使用java代码。安全

3、实际开发中：1+2

注册流程

2.代码编写

1.bean包：

User.java:

package com.heima.bean;

import java.io.Serializable;
import java.util.Date;

public class User implements Serializable{

private String username ;

private String password ;

private String email ;

private Date birthday ;

public String getUsername() {
return username;
}

public void setUsername(String username) {
this.username = username;
}

public String getPassword() {
return password;
}

public void setPassword(String password) {
this.password = password;
}

public String getEmail() {
return email;
}

public void setEmail(String email) {
this.email = email;
}

public Date getBirthday() {
return birthday;
}

public void setBirthday(Date birthday) {
this.birthday = birthday;
}
}

UserFormBean.java:

package com.heima.web.formbean;

import java.util.HashMap;
import java.util.Map;

import org.apache.commons.beanutils.locale.converters.DateLocaleConverter;

//此bean专门用来封装页面的数据
public class UserFormBean {

private String username;

private String password;

private String repassword;

private String email;

private String birthday;

private Map<String,String> errors = new HashMap<String,String>() ;

public Map<String, String> getErrors() {
return errors;
}

public String getUsername() {
return username;
}

public String getPassword() {
return password;
}

public String getRepassword() {
return repassword;
}

public void setRepassword(String repassword) {
this.repassword = repassword;
}

public void setPassword(String password) {
this.password = password;
}

public void setUsername(String username) {
this.username = username;
}

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;
}

//服务端验证
public boolean validate(){
//验证用户名
if(username == "" || username == null){
errors.put("username", "用户名不能为空") ;
}else{
if(username.length() > 8 || username.length() < 3){
errors.put("username", "用户名长度必须在3~8位之间") ;
}
}

//验证密码
if(password == "" || password == null){
errors.put("password", "密码不能为空") ;
}else{
if(password.length() > 8 || password.length() < 3){
errors.put("password", "密码长度必须在3~8位之间") ;
}
}

if(!repassword.equals(password)){
errors.put("password", "两次密码输入不一致") ;
}

//验证邮箱
if(email == "" || email == null){
errors.put("email", "邮箱不能为空") ;
}else{
if(!email.matches("^([a-zA-Z0-9_\\-\\.]+)@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.)|(([a-zA-Z0-9\\-]+\\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$"))
errors.put("email", "邮箱格式不正确") ;
}

//验证生日
if(birthday == "" || birthday == null){
errors.put("birthday", "生日不能为空") ;
}else{
//			SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd") ;
//			try {
//				sdf.parse(birthday) ;
//			} catch (ParseException e) {
//				// TODO Auto-generated catch block
//				e.printStackTrace();
//			}

DateLocaleConverter dlc = new DateLocaleConverter() ;
try {
dlc.convert(birthday) ;
} catch (Exception e) {
errors.put("birthday", "日期格式错误") ;
}
}

return errors.isEmpty() ;
}
}

2.service层：业务逻辑层（数据服务层，为页面服务）

UserService:

package com.heima.service;

import com.heima.bean.User;
import com.heima.exception.UserExistsException;

public interface UserService {

/**
* 根据用户名和密码登录
* @param username 用户名
* @param password 密码
* @return 登录成功返回此用户，否则返回null
*/
public User login(String username,String password ) ;

/**
* 注册用户
* @param user 要注册的用户
* @throws UserExistsException 当用户名已经存在的时候，抛出一个用户已存在异常
*/
public void register(User user) throws UserExistsException ;
}

UesrServiceImpl.java:

package com.heima.service.impl;

import com.heima.bean.User;
import com.heima.dao.UserDao;
import com.heima.dao.impl.UserDaoImpl;
import com.heima.exception.UserExistsException;
import com.heima.service.UserService;

public class UserServiceImpl implements UserService {

UserDao dao = new UserDaoImpl() ;

public User login(String username, String password) {
return dao.findUserByUserNameAndPassword(username, password);
}

public void register(User user) throws UserExistsException {
//查找用户
User u = dao.findUserByUserName(user.getUsername()) ;
if(u == null)
//说明用户没有注册过
dao.add(user) ;
else
throw new UserExistsException() ;
}
}

异常包：exception

UserExistsException.java:

package com.heima.exception;

public class UserExistsException extends Exception {

}

3.dao层：数据访问层（和数据库关联）

UserDao:

package com.heima.dao;

import com.heima.bean.User;

public interface UserDao {

/**
* 根据用户名和密码查询用户
* @param username 用户名
* @param password 密码
* @return 查询到用户返回此用户，否则返回null
*/
public User findUserByUserNameAndPassword(String username,String password) ;

/**
* 注册用户
* @param user 要注册的用户
*/
public void add(User user) ;

/**
* 根据用户的名字查找用户
* @param name 用户的名字
* @return 查询到了返回此用户，否则返回null
*/
public User findUserByUserName(String name) ;
}

实现：

package com.heima.dao.impl;

import java.text.ParseException;
import java.text.SimpleDateFormat;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Node;

import com.heima.bean.User;
import com.heima.dao.UserDao;
import com.heima.utils.JaxpUtils;

public class UserDaoImpl implements UserDao {
//要操作xml文档，读取进来再写回去
public User findUserByUserNameAndPassword(String username, String password) {
//加载Dom树
Document document = JaxpUtils.getDocument() ;
//查询需要的node节点
Node node = document.selectSingleNode("//user[@username='" + username+ "' and @password='" + password + "']") ;
if(node != null){
//找到了用户，封装数据
User user = new User() ;
user.setUsername(username) ;
user.setPassword(password) ;
user.setEmail(node.valueOf("@email")) ;
String birthday = node.valueOf("@birthday") ;

try {
user.setBirthday(new SimpleDateFormat("yyyy-MM-dd").parse(birthday)) ;
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return user;
}

return null;
}

public void add(User user) {
//加载dom树
Document document = JaxpUtils.getDocument() ;
//拿到根节点
Element root = document.getRootElement() ;
//添加一个user节点
root.addElement("user").addAttribute("username", user.getUsername())
.addAttribute("password", user.getPassword())
.addAttribute("email", user.getEmail())
.addAttribute("birthday", new SimpleDateFormat("yyyy-MM-dd").format(user.getBirthday())) ;

//将dom树保存到硬盘上
JaxpUtils.write2xml(document) ;

}

public User findUserByUserName(String name) {
//加载Dom树
Document document = JaxpUtils.getDocument() ;
//查询需要的node节点
Node node = document.selectSingleNode("//user[@username='" + name +"']") ;
if(node != null){
//找到了用户，封装数据
User user = new User() ;
user.setUsername(name) ;
user.setPassword("@password") ;
user.setEmail(node.valueOf("@email")) ;
String bithday = node.valueOf("@birthday") ;

try {
user.setBirthday(new SimpleDateFormat("yyyy-MM-dd").parse(bithday)) ;
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return user;
}
return null;
}

}

4.utils包

JaxpUtils.java:

package com.heima.utils;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

//操作XML文件的方法
public class JaxpUtils {

static String path ;

static{
path = JaxpUtils.class.getClassLoader().getResource("users.xml").getPath() ;
}

public static Document getDocument(){
//创建一个dom4j解析器
try {
SAXReader reader = new SAXReader() ;
Document document = reader.read(path) ;
return document ;
} catch (DocumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null ;
}

public static void write2xml(Document document){
try {
XMLWriter writer = new XMLWriter(new FileOutputStream(path), OutputFormat.createPrettyPrint()) ;
writer.write(document) ;
writer.close() ;
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}

WebUtils.java:

package com.heima.utils;

import java.lang.reflect.InvocationTargetException;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.beanutils.BeanUtils;

//专门为页面服务: 封装了页面的信息
public class WebUtils {

/**
* @param clazz 往那个对象里面封装，把类型传递进来
* @param request 从request对象中取出数据
* @return
*/
public static <T> T fillFormBean(Class<T> clazz,HttpServletRequest request){
T t = null ;
try {
t = clazz.newInstance() ;
BeanUtils.populate(t, request.getParameterMap()) ;
} catch (Exception e) {
e.printStackTrace();
}
return t ;
}
}

控制器：

RegisterServlet.java:

package com.heima.web.serlvet;

import java.io.IOException;
import java.io.PrintWriter;
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 com.heima.bean.User;
import com.heima.exception.UserExistsException;
import com.heima.service.UserService;
import com.heima.service.impl.UserServiceImpl;
import com.heima.utils.WebUtils;
import com.heima.web.formbean.UserFormBean;
//完成注册的功能
public class RegisterServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();

//第一步，先封装数据到userbean中   把页面的数据封装到UserFormBean中
UserFormBean ufb = WebUtils.fillFormBean(UserFormBean.class, request) ;

//第二步，验证数据
if(ufb.validate()){
//说明验证通过
//第三步,将formbean中的数据拷贝到user对象
User user = new User() ;
//由于formbean中的生日是String类型,userbaen中的生日是Date类型，beanUtils类不能自动转换，因此必须注册一个日期类型转换器
try {
ConvertUtils.register(new DateLocaleConverter(), Date.class) ;
BeanUtils.copyProperties(user, ufb) ;
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

//第四步,注册用户
//调用业务逻辑层完成注册
UserService us = new UserServiceImpl() ;
try {
us.register(user) ;
//注册成功
//返回登陆页面
response.getWriter().write("恭喜你，注册成功，2秒后转向登陆页面") ;
response.setHeader("Refresh", "2;url=" + request.getContextPath() + "/login.jsp") ;
//response.sendRedirect(request.getContextPath() + "/login.jsp") ;

} catch (UserExistsException e) {
//说明用户已经注册过了
ufb.getErrors().put("username", "此用户名已经被注册过了，请换一个") ;
//将ufb存入request对象
request.setAttribute("user", ufb) ;
request.getRequestDispatcher("/register.jsp").forward(request, response) ;
}

}else{
//验证不通过
//完成数据的回显操作，把ufb对象存放到request
request.setAttribute("user", ufb) ;
request.getRequestDispatcher("/register.jsp").forward(request, response) ;
}
}

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

}

LoginServlet.java:

package com.heima.web.serlvet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.heima.bean.User;
import com.heima.service.UserService;
import com.heima.service.impl.UserServiceImpl;

public class LoginServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();

//获取页面的数据
String name = request.getParameter("username") ;
String pass = request.getParameter("password") ;

//验证数据(略)

//调用service层完成业务逻辑
UserService us = new UserServiceImpl() ;
User user = us.login(name, pass) ;
if(user != null){
//合法用户
request.getSession().setAttribute("loginuser", user) ;
request.getRequestDispatcher("/main.jsp").forward(request, response) ;
}else{
//非法用户
request.getSession().setAttribute("error", "用户名或者密码错误") ;
response.sendRedirect(request.getContextPath() + "/login.jsp") ;
}
}

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

}

视图层：

index.jsp:

<body>
<a href = "register.jsp">注册</a>
<a href = "login.jsp">登陆</a>
</body>

register.jsp:

<style type="text/css">
table{
width:900px;
border:1px solid gray ;
border-collapse: collapse;
}
table td{
border:1px solid gray ;
}

</style>
</head>

<body>
<h1>注册用户</h1>
<hr>
<center>
<form action="${pageContext.request.contextPath }/servlet/RegisterServlet" method="post">
<table>
<tr>
<td align  ="right">姓名：</td>
<td align = "left"><input type = "text" name = "username" value = "${user.username }"></td>
<td><span>${user.errors.username }</span></td>
</tr>
<tr>
<td align  ="right">密码：</td>
<td align = "left"><input type = "password" name = "password" ></td>
<td><span>${user.errors.password }</span></td>
</tr>
<tr>
<td align  ="right">确认密码：</td>
<td align = "left"><input type = "password" name = "repassword" ></td>
<td></td>
</tr>
<tr>
<td align  ="right">邮箱：</td>
<td align = "left"><input type = "text" name = "email" value = "${user.email }"></td>
<td><span>${user.errors.email }</span></td>
</tr>
<tr>
<td align  ="right">生日：</td>
<td align = "left"><input type = "text" name = "birthday" value = "${user.birthday }"></td>
<td><span>${user.errors.birthday }</span></td>
</tr>
<tr>
<td colspan = "3" align = "center"><input type = "submit" value = "注册"></td>
</tr>
</table>
</form>
</center>
</body>
</html>

login.jsp:

<body>
<center>
<h1>登陆页面</h1>
<hr>
<font color =red>${error }</font>
<form action="${pageContext.request.contextPath }/servlet/LoginServlet" method="post">
<table>
<tr>
<td align  ="right">姓名：</td>
<td align = "left"><input type = "text" name = "username" ></td>
<td><span></span></td>
</tr>
<tr>
<td align  ="right">密码：</td>
<td align = "left"><input type = "password" name = "password" ></td>
<td><span></span></td>
</tr>
<tr>
<td colspan = "3"><input type = "submit" value = "登陆"></td>
</tr>
</table>
</form>
</center>
</body>

main.jsp:

<body>
${loginuser.username },欢迎你
</body>