怎么把null去掉
<%--
COPYRIGHT (C) 2014-2015 BY MULDINI. ALL RIGHTS RESERVED.
--%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<% request.setCharacterEncoding("UTF-8"); %>
<%-- 从当前page中取id为singer的对象，该对象类型为com.muldini.myface.common.Singer --%>
<%-- 若无则新建1个Singer类型对象，该对象id为“singer”，并将其存入page。默认scope就是page--%>
<jsp:useBean id="singer" class="com.muldini.myface.common.Singer" scope="page" />
<%--把客户端request中的name和rank参数值分别赋给id为singer的对象的name和rank属性 --%>
<jsp:setProperty name="singer" property="name" param="name"/>
<jsp:setProperty name="singer" property="rank" param="rank"/>
<%--TOSHOW1<jsp:setProperty name="singer" property="*"/> --%>
<%--TOSHOW2<% String player = "Inzaghi"; %>
<jsp:setProperty name="singer" property="name" value="<%=player %>"/>--%>
<%--TOSHOW3<jsp:setProperty name="singer" property="name" value="Pippo"/>--%>
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" type="text/css" href="css/myface.css">
<title>I am a player</title>
<script type="text/javascript">
function validate() {
if (myform.name.value == null) {
alert("请您输入巨星名");
return false;
}
if (myform.rank.value == 0) {
alert("请您选择巨星排名");
return false;
}
return true;
}
</script>
</head>
<body>
<div>
<div id="left">
<img id="singer-img" src="image/iamasinger.png">
</div>
<div id="right">
<%--取得id为singer的对象的name和rank属性值 --%>
球星: <jsp:getProperty name="singer" property="name" /><br>
排名: <jsp:getProperty name="singer" property="rank" /><br><br><br>
<form name="myform" method="post" action="iamasinger.jsp" onsubmit="return validate()">
Enter a 球星 name:
<input type="text" name="name" size="25"><br><br>
Choose a Player 排名:
<select name="rank">
<option value="0">请选择</option>
<option value="1">第1名</option>
<option value="2">第2名</option>
<option value="3">第3名</option>
<option value="4">第4名</option>
<option value="5">第5名</option>
<option value="6">第6名</option>
<option value="7">第7名</option>
</select>
<input type="submit" value="Submit">
</form>
</div>
</div>
</body>
</html>
erutdioup8556浏览 1757回答 1
1回答
-
echo_kinchao
因为这个名字没有获取到 才会给的Null
随时随地看视频慕课网APP
Html5
CSS3