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;
}
}
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 errors = new HashMap() ;
public Map 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) ;
}
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 fillFormBean(Class 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:
注册
登陆
register.jsp:
注册用户