javaBean
第一种使用方法
index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <%@ page import="com.po.Users" %> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'reg.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <% Users user = new Users() ; user.setUsername("zhang"); user.setPassword("zzz111"); %> <h1>普通创建javabean</h1> 用户名:<br><%=user.getUsername() %> 密码:<br><%=user.getPassword() %> </body> </html>
users.java
package com.po; public class Users{ private String username ; private String password ; public Users(){} public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } }
第二种使用
动作标签的使用
useBeans的使用
<jsp:useBean id=”标示符” calss=”java类名字” scope=”作用范围”/>
setProperty
login.jsp
<body> <h1>系统登录</h1> <hr> <form name="loginForm" action="dologin.jsp" method="post"> <table> <tr> <td>用户名:</td> <td><input type="text" name="username" value=""/></td> </tr> <tr> <td>密码</td> <td><input type="password" name="password" value=""/></td> </tr> <tr> <td>提交</td> <td colspan="2" align="center"><input type="submit" value="登录"/></td> </tr> </table> </form> </body>
dologin.jsp
<body> <jsp:useBean id="myUsers" class="com.po.Users" scope="page" /> <h1>setProperty动作元素</h1> <hr> <!-- 第一 根据表单自动匹配所有的 属性--> <jsp:setProperty property="*" name="myUsers"/> 用户名:<%=myUsers.getUsername() %><br> 密码: <%=myUsers.getPassword() %><br> </body>
<body> <jsp:useBean id="myUsers" class="com.po.Users" scope="page" /> <h1>setProperty动作元素</h1> <hr> <jsp:setProperty property="*" name="myUsers"/> <!-- 使用传统的表达式方式获取用户名密码 用户名:<%=myUsers.getUsername() %><br> 密码: <%=myUsers.getPassword() %><br> --> <!-- 使用getProperty方式获取 --> 用户名:<jsp:getProperty name="myUsers" property="username"/> 密码:<jsp:getProperty name="myUsers" property="password"/> </body>