下面一个javaBean实例:
1、使用普通方式创建javabean的实例
<%@ page language="java" import="java.util.*" contentType="text/html; charset=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 'index.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("admin"); //设置用户名 user.setPassword("123456");//设置密码 %> <h1>使用普通方式创建javabean的实例</h1> <hr> 用户名:<%=user.getUsername() %><br> 密码:<%=user.getPassword() %><br> </body> </html>
<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%> <% 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 'index.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> <jsp:useBean id="myUsers" class="com.po.Users" scope="page"/> <h1>使用useBean动作创建javabean的实例</h1> <hr> 用户名:<%=myUsers.getUsername() %><br> 密码:<%=myUsers.getPassword() %><br> </body> </html>
因为上面程序没有使用setProperty,所以用户名和密码都是null。
下面使用setProperty:
JavaBean可以封装数据也可以封装业务逻辑。