1.创建项目，编写JavaBean
（1）编写UserBean类
在Eclipse中创建一个名称为chapter11的Web项目，在项目的 src目录下创建包baixiao.model2.domain,在包中定义UserBean类，用于封装用户信息
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| package baixiao.model2.domain;
public class UserBean {
private String name;
private String password;
private String email;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
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;
}
}
|
(2）编写RegisterFormBean类
在baixiao.model2.domain包中定义RegisterFormBean类,用于封装注册表单信息
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| package baixiao.model2.domain;
import java.util.HashMap;
import java.util.Map;
public class RegisterFormBean {
private String name;
private String password;
private String password2;
private String email;
private Map<String, String> errors = new HashMap<String, String>();
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getPassword2() {
return password2;
}
public void setPassword2(String password2) {
this.password2 = password2;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public boolean validate() {
boolean flag = true;
if (name == null || name.trim().equals("")) {
errors.put("name", "请输入姓名.");
flag = false;
}
if (password == null || password.trim().equals("")) {
errors.put("password", "请输入密码.");
flag = false;
}else if (password.length() > 12 || password.length() < 6) {
errors.put("password", "请输入6-12个字符");
flag = false;
}
if (password != null && !password.equals(password2)) {
errors.put("password2", "两次输入的密码不匹配.");
flag = false;
}
if (email == null || email.trim().equals("")) {
errors.put("email", "请输入邮箱.");
flag = false;
}else if (!email.matches("[a-zA-Z0-9_-]+@[a-zA-Z0-9_-]+(\\.[a-zA-Z0-9_-]+)+")) {
errors.put("email", "邮箱格式错误");
flag = false;
}
return flag;
}
public void setErrorMsg(String err, String errMsg) {
if ((err != null) && (errMsg != null)) {
errors.put(err, errMsg);
}
}
public Map<String, String> getErrors(){
return errors;
}
}
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该JavaBean中除了定义了一些属性和成员变量外，还定义了3个方法。
其中，setErrorMsg(）方法用于向errors集合中存放错误信息，getErrors()方法用于获取封装错误信息的errors集合,
validlate()方法用于对注册表单内各字段所填写的数据进行校验。
2.创建工具类
在chapter11项目的src下创建包baixiao.model2.util,在包中定义DBUtil 类。
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| package baixiao.model2.util;
import java.util.HashMap;
import pidan.model2.domain.UserBean;
public class DBUtil {
private static DBUtil instance = new DBUtil();
private HashMap<String, UserBean> users = new HashMap<String, UserBean>();
private DBUtil() {
UserBean user1 = new UserBean();
user1.setName("Pidan");
user1.setPassword("12345678");
user1.setEmail("Pidan@qq.com");
users.put("Pidan", user1);
UserBean user2 = new UserBean();
user2.setName("HYS");
user2.setPassword("abcdegfg");
user2.setEmail("HYS@qq.com");
}
public static DBUtil getInstance() {
return instance;
}
public UserBean getUser(String userName) {
UserBean user = (UserBean) users.get(userName);
return user;
}
public boolean insertUser(UserBean user) {
if (user == null) {
return false;
}
String userName = user.getName();
if (users.get(userName) != null) {
return false;
}
users.put(userName, user);
return true;
}
}
|
定义的DBUl是一个单例类，它实现了两个功能。第1个功能是定义一个HashMap集合users，用于模拟数据库，
并向数据库中存入了两条学生的信息。第2个功能是定义getUser()方法和insertUser()方法来操作数据库。其中，getUser()方法用于获取数据库中的用户信息，insertUser()方法用于向数据库中插入用户信息。需要注意的是，在insertUser()方法进行信息插入操作之前，会判断数据库中是否存在同名的学生信息。如果存在，则不执行插入操作，方法返回false；反之表示插入操作成功，方法返回 true。
3.创建Servlet
在chapter11项目下创建包pidan.model2.web,在包中定义ControllerServlet类，使用该类来处理用户请求
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| package baixiao.model2.web;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import pidan.model2.domain.RegisterFormBean;
import pidan.model2.domain.UserBean;
import pidan.model2.util.DBUtil;
@WebServlet("/ControllerServlet")
public class ControllerServlet extends HttpServlet{
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
this.doPost(request, response);
}
public void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException{
response.setHeader("Content-type", "text/html;charset=GBK");
response.setCharacterEncoding("GBK");
String name = request.getParameter("name");
String password = request.getParameter("password");
String password2 = request.getParameter("password2");
String email = request.getParameter("email");
RegisterFormBean formBean = new RegisterFormBean();
formBean.setName(name);
formBean.setPassword(password);
formBean.setPassword2(password2);
formBean.setEmail(email);
if (!formBean.validate()) {
request.setAttribute("formBean", formBean);
request.getRequestDispatcher("/register.jsp").forward(request, response);
return;
}
System.out.println("!!!");
UserBean userBean = new UserBean();
userBean.setName(name);
userBean.setPassword(password);
userBean.setEmail(email);
boolean b = DBUtil.getInstance().insertUser(userBean);
if (!b) {
request.setAttribute("DBMes", "你注册的用户已存在");
request.setAttribute("formBean", formBean);
request.getRequestDispatcher("/register.jsp").forward(request, response);
return;
}
response.getWriter().print("注册成功，3秒后自动跳转");
request.getSession().setAttribute("userBean", userBean);
response.setHeader("refresh", "3;url = loginSuccess.jsp");
}
}
|
创建的RegisterFormBean对象用于封装表单提交的信息。当对RegisterFormBean对象进行校验时，如果校验失败，程序就会跳转到register.jsp注册页面，让用户重新填写注册信息。
如果校验通过，那么注册信息就会封装到UserBean对象中，并通过DBUtil的insertUser()方法将UserBean对象插入到数据库。
insertUser()方法有一个boolean类型的返回值，如果返回false，表示插入操作失败，程序跳转到register.jsp注册页面；反之，程序跳转到loginSuccess.jsp页面，表示用户登录成功。
需要注意的是，编写完ControllerServlet类之后，读者不要忘记在web.xml文件中配置其映射信息。
4.创建JSP页面
（1）编写register.jsp 文件
在项目的WebContent目录下创建register.jsp文件，该文件是用户注册的表单页面，用于接收用户的注册信息。
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| <%@ page language="java" pageEncoding="GBK"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01
Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>用户注册</title>
<style type="text/css">
h3 {
margin-left: 100px;
}
#outer {
width: 750px;
}
span {
color: #ff0000
}
div {
height:20px;
margin-bottom: 10px;
}
.ch {
width: 80px;
text-align: right;
float: left;
}
.ip {
width: 500px;
float: left
}
.ip>input {
margin-right: 20px
}
#bt {
margin-left: 50px;
}
#bt>input {
margin-right: 30px;
}
</style>
</head>
<body>
<form action="ControllerServlet" method="Post">
<h3>用户注册</h3>
<div id="outer">
<div>
<div class="ch">姓名:</div>
<div class="ip">
<input type="text" name="name" value="${formBean.name }" />
<span>${formBean.errors.name}${DBMes}</span>
</div>
</div>
<div>
<div class="ch">密码:</div>
<div class="ip">
<input type="password" name="password" />
<span>${formBean.errors.password}</span>
</div>
</div>
<div>
<div class="ch">确认密码:</div>
<div class="ip">
<input type="password" name="password2" />
<span>${formBean.errors.password2}</span>
</div>
</div>
<div>
<div class="ch">邮箱:</div>
<div class="ip">
<input type="text" name="email" value="${formBean.email }" />
<span>${formBean.errors.email}</span>
</div>
</div>
<div id="bt">
<input type="reset" value="重置 " />
<input type="submit" value="注册" />
</div>
</div>
</form>
</body>
</html>
|
(2)编写loginSuccess.jsp文件
在WebContent目录下创建loginSuccess.jsp文件，该文件是用户登录成功的页面
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| <%@ page language="java" pageEncoding="GBK" import="pidan.model2.domain.UserBean"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01
Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>login successfully</title>
<style type="text/css">
#main {
width: 500px;
height: auto;
}
#main div {
width: 200px;
height: auto;
}
ul {
padding-top: 1px;
padding-left: 1px;
list-style: none;
}
</style>
</head>
<body>
<div id="main">
<div id="welcome">恭喜你，登录成功</div>
<hr />
<div>您的信息</div>
<div>
<ul>
<li>您的姓名: ${userBean.name }</li>
<li>您的邮箱:${userBean.email}</li>
<li>您的邮箱:${userBean.password}</li>
</ul>
</div>
</div>
</body>
</html>
|
5.运行程序，测试结果
将chapter11项目发布到Tomcat服务器，并启动服务器，
然后在浏览器地址栏中输入地址“http://localhost:8080/chapter11/register.jsp”访问register.jsp页面，浏览器的显示结果如图
