计算器 & 登录注册 案例 model1 model2 开发模式 BeanUtils
JSP 两种开发模式
JSP model1 : JSP + JavaBean 组合 ，适合开发中小型简单应用，JSP负责业务流程控制、页面显示；JavaBean 负责数据封装和处理
JSP model2 : Servlet + JSP + JavaBean 组合，符合MVC 设计模式，适合开发业务流程复杂大型应用，JSP 只负责页面显示，JavaBean负责数据封装和处理，Servlet负责业务流程控制，JavaBean、JSP调度 --------- 分工明确，便于维护
计算器案例:
calculator.jsp
<%@ 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>Insert title here</title> <script type="text/javascript"> function validateForm(){ var first = document.getElementById("first").value; // 这个v必须小写 var second = document.getElementById("second").value; // 判断两个参数 必须为数字 if(isNaN(first) || isNaN(second)){ // 输入非法 alert("输入的参数必须为数字！"); return false; // 阻止form 提交 } } </script> </head> <body> <!-- 页面由两个部分组成 --> <!-- 显示运算结果 --> <!-- 封装请求参数 到JavaBean对象中 --> <jsp:useBean id="calculator" class="cn.itcast.domain.Calculator" scope="page"></jsp:useBean> <jsp:setProperty property="*" name="calculator"/> <!-- 执行运算，显示计算结果 --> <h3>计算结果是 ：${calculator.firstNum } ${calculator.operator } ${calculator.secondNum } = ${calculator.result }</h3> <hr/> <!-- 计算参数输入form表单 --> <form action="/day9/calculator.jsp" method="post" onsubmit="return validateForm();"> <table> <tr> <td>第一个参数</td> <td><input type="text" name="firstNum" id="first"/></td> </tr> <tr> <td>运算符</td> <td> <select name="operator"> <option value="+">+</option> <option value="-">-</option> <option value="*">*</option> <option value="/">/</option> </select> </td> </tr> <tr> <td>第二个参数</td> <td><input type="text" name="secondNum" id="second" /></td> </tr> <tr> <td colspan="2"> <input type="submit" value="计算" /> </td> </tr> </table> </form> </body> </html>
Calculator.java
package cn.itcast.domain; import java.math.BigDecimal; /** * 存放计算器数据 * * @author seawind * */ public class Calculator { private String firstNum = "0"; private String operator = "+"; private String secondNum = "0"; private double result; public String getFirstNum() { return firstNum; } public void setFirstNum(String firstNum) { this.firstNum = firstNum; } public String getOperator() { return operator; } public void setOperator(String operator) { this.operator = operator; } public String getSecondNum() { return secondNum; } public void setSecondNum(String secondNum) { this.secondNum = secondNum; } public void setResult(double result) { this.result = result; } // 在获得result的时候，进行计算 public double getResult() { // 将两个参数 转换 double 类型 BigDecimal num1 = new BigDecimal(firstNum); BigDecimal num2 = new BigDecimal(secondNum); BigDecimal result = null; if (operator.equals("+")) { result = num1.add(num2); } else if (operator.equals("-")) { result = num1.subtract(num2); } else if (operator.equals("*")) { result = num1.multiply(num2); } else if (operator.equals("/")) { if (num2.doubleValue() == 0) { throw new RuntimeException("除数不能为0！"); } result = num1.divide(num2, 9, BigDecimal.ROUND_HALF_UP); } return result.doubleValue(); } // public double getResult() { // // 将两个参数 转换 double 类型 // double num1 = Double.parseDouble(firstNum); // double num2 = Double.parseDouble(secondNum); // if (operator.equals("+")) { // result = num1 + num2; // } else if (operator.equals("-")) { // result = num1 - num2; // } else if (operator.equals("*")) { // result = num1 * num2; // } else if (operator.equals("/")) { // if (num2 == 0) { // throw new RuntimeException("除数不能为0！"); // } // result = num1 / num2; // } // return result; // } }
登录注册案例:
index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <!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>Insert title here</title> </head> <body> <h1>主页</h1> <!-- 通过判断 session中信息，得知用户是否登陆 --> <c:if test="${empty existUser}"> 您还未登陆！ </c:if> <c:if test="${not empty existUser}"> 用户昵称：${existUser.nickname } 邮箱 ：${existUser.email } <a href="/day9user/invalidate" >注销</a> </c:if> <hr/> <a href="/day9user/regist.jsp">用户注册</a> <a href="/day9user/login.jsp">用户登陆</a> </body> </html>
regist.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> <script type="text/javascript"> // 点击切换验证码 function change(){ document.getElementById("myimg").src = "/day9user/checkimg?"+new Date().getTime(); } // 数据合法性 校验 function validateForm(){ // 获得需要校验内容的value属性 var username = document.getElementById("username").value; if(username == ""){ alert("用户名不能为空"); return false; } var password = document.getElementById("password").value; if(password==""){ alert("密码不能为空！"); return false; } var repassword = document.getElementById("repassword").value; if(password != repassword){ alert("两次密码输入不一致！"); return false; } // 省略昵称为空、验证码为空判断 var email = document.getElementById("email").value; // 正则表达式 (\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*;)* if(email.match("^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+\\.([a-zA-Z0-9_-])+$")==null){ // 不匹配 alert("邮箱的地址非法！"); return false; } } </script> </head> <body> <h1>用户注册页面</h1> <h3 style="color:red">${msg }</h3> <form onsubmit="return validateForm();" action="/day9user/regist" method="post"> <table> <tr> <td>用户名</td> <td><input type="text" name="username" id="username"/></td> </tr> <tr> <td>密码</td> <td><input type="password" name="password" id="password"/></td> </tr> <tr> <td>确认密码</td> <td><input type="password" name="repassword" id="repassword"/></td> </tr> <tr> <td>昵称</td> <td><input type="text" name="nickname" id="nickname"/></td> </tr> <tr> <td>邮箱</td> <td><input type="text" name="email" id="email" /></td> </tr> <tr> <td>验证码</td> <td><input type="text" name="checkcode" id="checkcode"/> <img src="/day9user/checkimg" onclick="change();" id="myimg" style="cursor: pointer;"/></td> </tr> <tr> <td colspan=2"> <input type="submit" value="注册" /> </td> </tr> </table> </form> </body> </html>
RegistServlet.java
package cn.itcast.user.controller; import java.io.IOException; import java.lang.reflect.InvocationTargetException; 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 cn.itcast.user.model.User; import cn.itcast.user.model.UserOperation; /** * 注册 Servlet程序 * * @author seawind * */ public class RegistServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 处理 中文乱码 request.setCharacterEncoding("utf-8"); // 判断验证码信息是否有效 String checkcode_session = (String) request.getSession().getAttribute( "checkcode_session");// session中验证码 request.getSession().removeAttribute("checkcode_session"); String checkcode = request.getParameter("checkcode");// 用户输入验证码 if (checkcode_session == null || !checkcode_session.equals(checkcode)) { // 验证码输入错误 request.setAttribute("msg", "验证码输入错误！"); request.getRequestDispatcher("/regist.jsp").forward(request, response); return; } // 封装数据 JavaBean User user = new User(); try { BeanUtils.populate(user, request.getParameterMap()); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } // 需要另一个JavaBean处理数据 UserOperation userOperation = new UserOperation(); try { int result = userOperation.regist(user); // 判断注册结果 if (result == UserOperation.SUCCESS) { // 注册成功 response.sendRedirect("/day9user/login.jsp"); } else if (result == UserOperation.USERNAMEEXIST) { // 用户名已经存在 request.setAttribute("msg", "用户名已经存在"); request.getRequestDispatcher("/regist.jsp").forward(request, response); return; } else { // 邮箱已经存在 request.setAttribute("msg", "邮箱已经存在"); request.getRequestDispatcher("/regist.jsp").forward(request, response); return; } } catch (Exception e) { e.printStackTrace(); } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
UserOperation.java
package cn.itcast.user.model; import java.io.FileOutputStream; import java.util.List; import org.dom4j.Document; import org.dom4j.DocumentHelper; import org.dom4j.Element; import org.dom4j.io.OutputFormat; import org.dom4j.io.SAXReader; import org.dom4j.io.XMLWriter; /** * 数据处理的javabean * * @author seawind * */ public class UserOperation { public static final int SUCCESS = 1; public static final int USERNAMEEXIST = 2; public static final int EMAILEXIST = 3; // 用户登陆 // 如果方法返回boolean 只能知道登陆成功还是失败 // 有些情况，需要在登陆后，获得用户一些其它信息 --- 返回用户所有信息 public User login(User user) throws Exception { SAXReader reader = new SAXReader(); Document document = reader.read("d:\\users.xml"); Element users = document.getRootElement();// 根元素 List<Element> userList = users.elements("user"); // 判断用户名和密码是否正确 for (Element existUser : userList) { if (existUser.elementText("username").equals(user.getUsername()) && existUser.elementText("password").equals( user.getPassword())) { // 登陆成功,封装用户所有信息 user.setNickname(existUser.elementText("nickname")); user.setEmail(existUser.elementText("email")); return user; } } // 用户名和密码不存在 return null; } // 用户注册 public int regist(User user) throws Exception { // 读取XML （XML位置 磁盘固定位置或者 src目录） SAXReader reader = new SAXReader(); Document document = reader.read("d:\\users.xml"); // 判断输入用户信息中 用户名和邮箱是否存在 Element users = document.getRootElement(); List<Element> userList = users.elements("user"); for (Element existUser : userList) { if (existUser.elementText("username").equalsIgnoreCase( user.getUsername())) { // 用户名已经存在 return USERNAMEEXIST; } else if (existUser.elementText("email").equalsIgnoreCase( user.getEmail())) { // 邮箱已经存在 return EMAILEXIST; } } // 用户名和邮箱不存在，可以注册 Element newUserElement = DocumentHelper.parseText( "<user><username>" + user.getUsername() + "</username><password>" + user.getPassword() + "</password><nickname>" + user.getNickname() + "</nickname><email>" + user.getEmail() + "</email></user>").getRootElement(); users.add(newUserElement); // 回写数据到XML OutputFormat format = OutputFormat.createPrettyPrint(); // 自动换行 XMLWriter xmlWriter = new XMLWriter(new FileOutputStream( "d:\\users.xml"), format); xmlWriter.write(document); return SUCCESS; } }
login.jsp
<%@ 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>Insert title here</title>
</head>
<body>
<h1>登陆页面</h1>
<h3 style="color:red">${msg }</h3>
<form action="/day9user/login" method="post">
<table>
<tr>
<td>用户名</td>
<td><input type="text" name="username" value="${cookie.username.value }"/></td>
</tr>
<tr>
<td>密码</td>
<td><input type="password" name="password" value="${cookie.password.value }"/></td>
</tr>
<tr>
<td><input type="checkbox" name="remember" value="on" /></td>
<td>记住用户名和密码</td>
</tr>
<tr>
<td colspan="2">
<input type="submit" value="登陆" />
</td>
</tr>
</table>
</form>
</body>
</html>
LoginServlet.java
package cn.itcast.user.controller; import java.io.IOException; import java.lang.reflect.InvocationTargetException; import javax.servlet.ServletException; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.beanutils.BeanUtils; import cn.itcast.user.model.User; import cn.itcast.user.model.UserOperation; /** * 完成用户登陆功能 * * @author seawind * */ public class LoginServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 解决请求参数乱码 request.setCharacterEncoding("utf-8"); // 封装数据 到javabean User user = new User(); try { BeanUtils.populate(user, request.getParameterMap()); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } // 调用UserOperation 进行登陆操作 UserOperation userOperation = new UserOperation(); try { User existUser = userOperation.login(user); // 判断登陆是成功还是失败 if (existUser == null) { // 登陆失败 request.setAttribute("msg", "用户名或者密码错误！"); request.getRequestDispatcher("/login.jsp").forward(request, response); return; } else { // 登陆成功 // 将登陆用户信息 保存到Session request.getSession().setAttribute("existUser", existUser); // 记住用户名和密码 // 判断一下用户是否勾选了 记住选择框 if ("on".equals(request.getParameter("remember"))) { // 用户勾选了记住 选择框 Cookie usernameCookie = new Cookie("username", existUser .getUsername()); usernameCookie.setPath("/"); usernameCookie.setMaxAge(60 * 60 * 24 * 14);// 两个星期 response.addCookie(usernameCookie); Cookie passwordCookie = new Cookie("password", existUser .getPassword()); passwordCookie.setPath("/"); passwordCookie.setMaxAge(60 * 60 * 24 * 14);// 两个星期 response.addCookie(passwordCookie); } response.sendRedirect("/day9user/index.jsp"); return; } } catch (Exception e) { e.printStackTrace(); } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
InvalidateServlet.java
package cn.itcast.user.controller; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * 完成用户注销 * * @author seawind * */ public class InvalidateServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 销毁session request.getSession().invalidate(); // 跳转回主页 response.sendRedirect("/day9user/index.jsp"); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <servlet> <servlet-name>CheckImgServlet</servlet-name> <servlet-class>cn.itcast.user.view.CheckImgServlet</servlet-class> </servlet> <servlet> <servlet-name>RegistServlet</servlet-name> <servlet-class>cn.itcast.user.controller.RegistServlet</servlet-class> </servlet> <servlet> <servlet-name>LoginServlet</servlet-name> <servlet-class>cn.itcast.user.controller.LoginServlet</servlet-class> </servlet> <servlet> <servlet-name>InvalidateServlet</servlet-name> <servlet-class>cn.itcast.user.controller.InvalidateServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>CheckImgServlet</servlet-name> <url-pattern>/checkimg</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>RegistServlet</servlet-name> <url-pattern>/regist</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>LoginServlet</servlet-name> <url-pattern>/login</url-pattern> </servlet-mapping> <servlet-mapping> <servlet-name>InvalidateServlet</servlet-name> <url-pattern>/invalidate</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
