用户名为null
这是reg：
<%@ 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>
<h1>用户注册</h1>
<hr>
<form name = "regForm" action = "request.jsp" method= "post">
<table>
<tr>
<td>用户名:</td>
<td><input type = "text" name = "username"></td>
</tr>
<tr>
<td>爱好:</td>
<td>
<input type = "checkbox" name = "favorite" value = "read">读书
<input type = "checkbox" name = "favorite" value = "movie">电影
<input type = "checkbox" name = "favorite" value = "music">音乐
<input type = "checkbox" name = "favorite" value = "internet">上网
</td>
</tr>
<tr>
<td colspan ="2"><input type = "submit" value = "提交">
</td>
</tr>
</table>
</form>
<br>
<br>
<a href="request.jsp?username=lisi">测试url传参数</a>
</body>
</html>
--------------------------------------------------------------------------------------
这是request：
<%@ 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>
<h1>request内置对象</h1>
<%
request.setCharacterEncoding("utf-8") ;
%>
用户名:<%=request.getParameter("username")%><br>
爱好:<%
if(request.getParameterValues("favorite")!=null)
{
String[] favorites = request.getParameterValues("favorite");
for(int i =0;i<favorites.length;i++)
{
out.println(favorites[i]+"<br>"+"  ");
}
}
%>
</body>
</html>
