web day14 web版简单注册登陆案例
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项目
功能:
> 注册
> 登录
-------------
JSP:
*login.jsp --> 登录表单
*regist.jsp --> 注册表单
*index.jsp --> 主页(只有登录成功才能看到)
Servlet:
*LoginServlet
*RegistServlet
*VerifyCodeServlet
*QuitServlet
Service:
*UserService --> 与用户相关的业务类
Dao:
*UserDao --> 与用户相关的数据类
Domain:
*User(对应数据库,还要对应所有表单)
> username
> password
> verifyCode
-------------
数据库设计
*users.xml
<users>
<user username="xxx" password="xxx"/>
<user username="xxx" password="xxx"/>
</users>
-------------
项目框架搭建
步骤:
1. 创建空项目
2. 导包:
*CommonUtils
*commons-beanutils.jar
*commons-logging.jar
*dom4j
3. 建包
*cn.itcast.user.domain
> User
*cn.itcast.user.dao
> UserDao
*cn.itcast.user.service
> UserService
*cn.itcast.user.web.servlet
> LoginServlet
> RegistServlet
4. jsp
*login.jsp
*regist.jsp
*index.jsp
5. 在F盘下创建一个users.xml文件!
* 添加根元素<users>
* 保证文件为utf-8编码!!!
-------------
注册
regist.jsp
> 第一步:完成regist.jsp的基本功能!
RegistServlet
> 封装表单数据,封装到User对象中。
> 调用service的regist()方法
*如果这个方法没有出问题,输出“注册成功”
*如果这个方法抛出了异常,把错误信息保存到request域,转发到regist.jsp(显示错误信息)
UserService#regist()
> 没有返回值,但注册失败抛出一个自定义的异常!可以在异常中添加异常信息!(自定义一个异常类)
> 校验用户名是否已被注册(通过用户名查询用户),如果已被注册,抛出异常,异常信息为“用户名已被注册!”
> 添加用户
UserDao:通过业务分析,得到结果:需要提供两个方法
> 按用户名查询用户对象:UserfindByUsername(String username)
> 插入一个用户到数据库中:voidadd(User user)
工作:
1. 在service层添加一个UserException
2. dao;
*User findByUsername(String username)
*void add(User user)
3. service
*void regist() throws UserException
4. servlet
1).封装表单数据到User对象中
2).使用user调用service的regist()方法
3). 如果得到UserException,那么把异常信息保存到request域中,转发回regist.jsp,(数据的回显)
4). 输出“注册成功”
-------------------
给注册添加验证码
1. VerifyCode类
*BufferedImage getImage() --> 获取随机的验证码图片
*String getText() --> 获取图片上的文本
*static output(BfferedImage, OutputStream) --> 把图片写入到指定的输出流中。
2. VerifyCodeServlet
* 获取随机验证码图片
* 把验证码图片上的文本保存到session中
* 把图片响应到response的outputStream中
3. regist.jsp
* 添加<img src="指向Servlet" />
* 添加一个文本框,用来输入验证码
* “看不清,换一张”,是一个超链接。把上面的<img>的src重新再次指向Servlet!为了处理浏览器的缓存,需要使用时间来做参数!
4. 修改RegistServlet
* 校验验证码!
* 错误:保存表单数据到request域、保存错误信息到request域,转发回regist.jsp
* 正确:什么都不做,向下执行原来代码!
-------------------
服务器端表单(输入)校验
我们把这段校验,放到获取表单数据之后,验证码校验之前!
1. 使用Map类型来装载错误信息!
*key:表单项名称,例如:username、password、verifyCode
*value:
> 非空:用户名不能为空,或者是“密码不能为空”
> 长度:用户名长度必须在3~20之间 密码长度必须在3~20之间
2. 在校验失败时,向map添加错误信息!那个字段出错,就给哪个字段添加错误信息!
3. 判断map是否为空(长度是否为0),如果不空,说明有错误存在,保存map到request域,保存form到request域(回显),转发回regist.jsp
4. 在regist.jsp页面中,显示map中的错误信息。${map.username}
=================================
=================================
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登录功能
页面:login.jsp--> 登录表单!
LoginServlet -->
1. 获取表单数据,封装到User中
2. 调用service的login()方法,传递form过去!
3. 如果service的login()方法,没有抛出异常!返回一个User对象!
4. 有异常:获取异常信息,保存到request域,保存form,转发到login.jsp
5. 没异常:保存返回的user对象到session中!!!重定向到welcome.jsp(显示当前用户信息!)
UserService#login()
public User login(User form) {...}
1. 使用用户名查询数据库,得到返回的User
> 返回为null,抛出异常,异常信息为(用户名不存在)
> 返回不为null,获取查询出来的user的password与form的password进行比较!如果不同:抛出异常(密码错误!)\
> 如果相同,返回查询结果!
UserDao
1. 通过用户名查询用户!(已经存在了,不用再写了!)
====================================================
代码
服务器端表单校验(写入校验)
在jsp相应表单行添加map的全域属性查找显示(略)
/* * 添加新任务(表单校验) * 1. 创建一个Map,用来装载所有的表单错误信息 * 在校验过程中,如果失败,向map添加错误信息,其中key为表单字段名称 * 2. 校验之后,查看map长度是否大于0,如果大于0,说明有错误信息,就是有错误! * > 保存map到request中,保存form到request中,转发到regist.jsp * * 3. 如果map为空,说明没有错误信息,向下执行! */// 用来装载所有错误信息Map<String,String> errors = new HashMap<String,String>();// 对用户名进行校验String username = form.getUsername();//获取表单的usernameif(username == null || username.trim().isEmpty()) {errors.put("username", "用户名不能为空!");} else if(username.length() < 3 || username.length() > 15) {errors.put("username", "用户名长度必须在3~15之间!");}// 对密码进行校验String password = form.getPassword();if(password == null || password.trim().isEmpty()) {errors.put("password", "密码不能为空!");} else if(password.length() < 3 || password.length() > 15) {errors.put("password", "密码长度必须在3~15之间!");}// 对验证码进行校验String sessionVerifyCode = (String) request.getSession().getAttribute("session_vcode");String verifyCode = form.getVerifyCode();if(verifyCode == null || verifyCode.trim().isEmpty()) {errors.put("verifyCode", "验证码不能为空!");} else if(verifyCode.length() != 4) {errors.put("verifyCode", "验证码长度必须为4!");} else if(!verifyCode.equalsIgnoreCase(sessionVerifyCode)) {errors.put("verifyCode", "验证码错误!");}/* * 判断map是否为空,不为空,说明存在错误 */if(errors != null && errors.size() > 0) {/* * 1. 保存errors到request域 * 2. 保存form到request域,为了回显 * 3. 转发到regist.jsp */request.setAttribute("errors", errors);request.setAttribute("user", form);request.getRequestDispatcher("/user/regist.jsp").forward(request, response);return;}
UserDao
public class UserDao {private String path;public UserDao() {path = this.getClass().getResource("/users.xml").getPath();}public void add(User user) {try {SAXReader reader = new SAXReader();Document doc = reader.read(path);Element root = doc.getRootElement();Element userEle = root.addElement("user");userEle.addAttribute("username", user.getUsername());userEle.addAttribute("password", user.getPassword());// 创建格式化器,使用\t缩进,添加换行OutputFormat format = new OutputFormat("\t", true);// 清空数据中原有的换行format.setTrimText(true);// 创建XML输出流对象XMLWriter writer = new XMLWriter(new FileWriter(path), format);// 输出Documentwriter.write(doc);// 关闭流writer.close();} catch (Exception e) {throw new RuntimeException(e);}}public User findByUsername(String username) {try {SAXReader reader = new SAXReader();Document doc = reader.read(path);Element ele = (Element) doc.selectSingleNode("//user[@username='" + username + "']");if(ele == null) {return null;}User user = new User();user.setUsername(ele.attributeValue("username"));user.setPassword(ele.attributeValue("password"));return user;} catch (Exception e) {throw new RuntimeException(e);}}}
UserService
public class UserService {private UserDao userDao = new UserDao();public User login(String username, String password) throws UserException {User user = userDao.findByUsername(username);if(user == null) {throw new UserException("用户名错误!");}if(!user.getPassword().equals(password)) {throw new UserException("密码错误!");}return user;}public void regist(User user) throws UserException {User _user = userDao.findByUsername(user.getUsername());if(_user != null) {throw new UserException("用户名已注册!");}userDao.add(user);}}
UserException
public class UserException extends Exception {public UserException() {}public UserException(String message, Throwable cause) {super(message, cause);}public UserException(String message) {super(message);}public UserException(Throwable cause) {super(cause);}}
QuitServlet
public class QuitServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {// 使session失效request.getSession().invalidate();response.sendRedirect(request.getContextPath() + "/index.jsp");}}
LoginServlet
public class LoginServlet extends HttpServlet {public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.setCharacterEncoding("utf-8");response.setContentType("text/html;charset=utf-8");String username = request.getParameter("username");String password = request.getParameter("password");String loginCode = request.getParameter("loginCode");if(username == null || username.trim().isEmpty()) {request.setAttribute("msg", "用户名不能为空!");request.setAttribute("username", username);request.getRequestDispatcher("/login.jsp").forward(request, response);return;}if(password == null || password.trim().isEmpty()) {request.setAttribute("msg", "密码不能为空!");request.setAttribute("username", username);request.getRequestDispatcher("/login.jsp").forward(request, response);return;}if(loginCode == null || loginCode.trim().isEmpty()) {request.setAttribute("msg", "验证码不能为空!");request.setAttribute("username", username);request.getRequestDispatcher("/login.jsp").forward(request, response);return;}String vCode = (String)request.getSession().getAttribute("loginCode");request.getSession().removeAttribute("loginCode");if(!vCode.equalsIgnoreCase(loginCode)) {request.setAttribute("msg", "验证码错误!");request.setAttribute("username", username);request.getRequestDispatcher("/login.jsp").forward(request, response);return;}UserService userService = new UserService();User user;try {user = userService.login(username, password);} catch (UserException e) {request.setAttribute("msg", e.getMessage());request.setAttribute("username", username);request.getRequestDispatcher("/login.jsp").forward(request, response);return;}request.getSession().setAttribute("user", user);request.getRequestDispatcher("/index.jsp").forward(request, response);}}
RegistServlet
public class RegistServlet extends HttpServlet {public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.setCharacterEncoding("utf-8");response.setContentType("text/html;charset=utf-8");User user = new User();try {BeanUtils.populate(user, request.getParameterMap());} catch (Exception e) {}String loginCode = request.getParameter("registCode");String repassword = request.getParameter("repassword");if(user.getUsername() == null || user.getUsername().trim().isEmpty()) {request.setAttribute("msg", "用户名不能为空!");request.setAttribute("user", user);request.getRequestDispatcher("/regist.jsp").forward(request, response);return;}if(user.getPassword() == null || user.getPassword().trim().isEmpty()) {request.setAttribute("msg", "密码不能为空!");request.setAttribute("user", user);request.getRequestDispatcher("/regist.jsp").forward(request, response);return;}if(!user.getPassword().equals(repassword)) {request.setAttribute("msg", "两次输入不一致!");request.setAttribute("user", user);request.getRequestDispatcher("/regist.jsp").forward(request, response);return;}if(loginCode == null || loginCode.trim().isEmpty()) {request.setAttribute("msg", "验证码不能为空!");request.setAttribute("user", user);request.getRequestDispatcher("/regist.jsp").forward(request, response);return;}String vCode = (String)request.getSession().getAttribute("registCode");request.getSession().removeAttribute("registCode");if(!vCode.equalsIgnoreCase(loginCode)) {request.setAttribute("msg", "验证码错误!");request.setAttribute("user", user);request.getRequestDispatcher("/regist.jsp").forward(request, response);return;}UserService userService = new UserService();try {userService.regist(user);request.getRequestDispatcher("/login.jsp").forward(request, response);} catch (UserException e) {request.setAttribute("msg", e.getMessage());request.setAttribute("user", user);request.getRequestDispatcher("/regist.jsp").forward(request, response);return;}}}
VerifyCodeServlet
public class VerifyCodeServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {String name = request.getParameter("name");VerifyCode vc = new VerifyCode();//创建验证码类BufferedImage image = vc.getImage();//创建验证码图片request.getSession().setAttribute(name, vc.getText());//获取验证码文本System.out.println(vc.getText());VerifyCode.output(image, response.getOutputStream());//输出图片到页面}}
index.jsp
<body> <h1>主页</h1> <hr/><c:choose><c:when test="${empty sessionScope.user }">您还没有登录</c:when><c:otherwise>用户名:${sessionScope.user.username }<a href="<c:url value='/QuitServlet'/>">退出</a></c:otherwise></c:choose> </body>
regist.jsp
<body> <h1>注册</h1> <hr/> <p style="font-weight: 900; color: red;">${msg }</p> <form action="<c:url value='/RegistServlet'/>" method="post"> 用户名:<input type="text" name="username" value="${user.username }" /><br/> 密 码:<input type="password" name="password"/><br/> 确认密码:<input type="password" name="repassword"/><br/> 验证码:<input type="text" name="registCode" size="2"/> <img id="vCode" src="<c:url value='/VerifyCodeServlet?name=registCode'/>" border="2"/> <a href="javascript:_change()" style="font-size: 12;">看不清,换一张</a><br/> <input type="submit" value="注册"/> </form> </body> <script type="text/javascript">function _change() {var img = document.getElementById("vCode");img.src = "<c:url value='/VerifyCodeServlet?name=registCode&'/>" + new Date().getTime();} </script>
login.jsp
<body> <h1>登录</h1> <hr/> <p style="font-weight: 900; color: red;">${msg }</p> <form action="<c:url value='/LoginServlet'/>" method="post"> 用户名:<input type="text" name="username" value="${user.username }" /><br/> 密 码:<input type="password" name="password"/><br/> 验证码:<input type="text" name="loginCode" size="2"/> <img id="vCode" src="<c:url value='/VerifyCodeServlet?name=loginCode'/>" border="2"/> <a href="javascript:_change()" style="font-size: 12;">看不清,换一张</a><br/> <input type="submit" value="登录"/> </form> </body> <script type="text/javascript"> function _change() { var img = document.getElementById("vCode"); img.src = "<c:url value='/VerifyCodeServlet?name=loginCode&'/>" + new Date().getTime(); } </script>
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