Cannot find any information on property '_name' in a bean of type 'com.user.
<%@ page language="java" import="java.util.*" pageEncoding="GB2312"%> <%@ page language="java" import="com.user.codercrazer.*"%> <% 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 'show.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="user1" class="com.user.codercrazer.User"/> <jsp:setProperty name="user1" property="name" param="_name"/> <jsp:setProperty name="user1" property="sex" param="_sex"/> <jsp:setProperty name="user1" property="tel" param="_tel"/> <jsp:setProperty name="user1" property="mail" param="_mail"/> <table> <tr> <td>姓名</td> <td><jsp:getProperty name="user1" property="name"/></td> </tr> <tr> <td>性别</td> <td><jsp:getProperty name="user1" property="sex"/></td> </tr> <tr> <td>电话</td> <td><jsp:getProperty name="user1" property="tel"/></td> </tr> <tr> <td>邮件</td> <td><jsp:getProperty name="user1" property="mail"/></td> </tr> </table> <hr/> <% User user =(User)pageContext.getAttribute("user1"); out.println(user.getName()+user.getTel()); %> </body> </html>
<jsp:useBean id="user1" class="com.user.codercrazer.User"/> <jsp:setProperty name="user1" property="name" param="_name"/> <jsp:setProperty name="user1" property="sex" param="_sex"/> <jsp:setProperty name="user1" property="tel" param="_tel"/> <jsp:setProperty name="user1" property="mail" param="_mail"/>
中的property的参数必须与该类中的setter和getter后面的名称要一致。不一致就出现Cannot find any information on property '_name' in a bean of type 'com.user.
出错之前的代码是
<jsp:useBean id="user1" class="com.user.codercrazer.User"/> <jsp:setProperty name="user1" property="_name" param="_name"/> <jsp:setProperty name="user1" property="_sex" param="_sex"/> <jsp:setProperty name="user1" property="_tel" param="_tel"/> <jsp:setProperty name="user1" property="_mail" param="_mail"/>
后来才发现<jsp:setProperty name="user1" property="_name" param="_name"/>的意思是user1.setName(_name)的意思，后来就想我这里是不是多了一个下划线呢，当时我把它理解为那个User类中的
变量名称，后来才仔细读了一遍，发现这里面的参数代表的意思不一样。param="_name"代表的意思是<%= request.parameter("_name")%>。
通过这次错误终于明白了java中的Usebean的应用。