為什么添加了判斷語(yǔ)句后愛(ài)好什么都沒(méi)有顯示
<%@ 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 'request.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>
<h1>request內(nèi)置對(duì)象</h1>
<%
request.setCharacterEncoding("UTF-8");
request.setAttribute("password", "123456");
%>
用戶名：<%=request.getParameter("username") %><br>
愛(ài)好：<% ?
if(request.getParameterValues("favortie")!=null){
String[] favorites = request.getParameterValues("favorite");
for(int i=0;i<favorites.length;i++)
{
out.println(favorites[i]+" ");
}
}
%>
密碼：<%=request.getAttribute("password") %><br>
請(qǐng)求體的MIME類型：<%=request.getContentType() %><br>
協(xié)議類型及版本號(hào)：<%=request.getProtocol() %><br>
服務(wù)器主機(jī)名：<%=request.getLocalName() %><br>
服務(wù)器端口號(hào)：<%=request.getLocalPort() %><br>
請(qǐng)求文件的長(zhǎng)度:<%=request.getContentLength() %><br>
請(qǐng)求客戶端的IP地址：<%=request.getLocalAddr() %><br>
請(qǐng)求的真實(shí)路徑:<%=request.getRealPath("request.jsp") %><br>
請(qǐng)求上下文的路徑：<%=request.getContextPath() %><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 '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>
? ? <h1>用戶注冊(cè)</h1>
? ? <hr>
? ? <form action="response.jsp" name="regForm" method="post">
? ? <table>
? ? <tr>
? ? <td>用戶名：</td>
? ? <td><input type="text" name="username"/></td>
? ? </tr>
? ? <tr>
? ? <td>愛(ài)好：</td>
? ? <td>
? ? <input type="checkbox" name="favorite" value="read"/>讀書(shū)
? ? <input type="checkbox" name="favorite" value="music"/>音樂(lè)
? ? <input type="checkbox" name="favorite" value="movie"/>電影
? ? <input type="checkbox" name="favorite" value="internet"/>上網(wǎng)
? ? </td>
? ? </tr>
? ? <tr>?
? ? <td colspan="2"><input type="submit" value="提交"/></td>
? ? </tr>
? ?
? ? </table>
? ? </form>
? ? <br>
? ? <br>
? ? <a href="request.jsp?username= 李四 " >測(cè)試URL傳參數(shù)</a>
??
? </body>
</html>
求大神看看為什么添加了判斷語(yǔ)句后愛(ài)好沒(méi)有顯示????
2016-04-30
if(request.getParameterValues("favortie")!=null) 你指的是這句么？
如果你沒(méi)勾選愛(ài)好肯定是不會(huì)顯示了，或者點(diǎn)擊超鏈接也沒(méi)有，因?yàn)槌溄記](méi)傳遞愛(ài)好，添加這句只是為了防止報(bào)空指針異常?out.println(favorites[i]+"   ");