输入username和password的界面：
<%@ page language="java" contentType="text/html;charset=gb2312" %>
<script type="text/javascript">
function on_submit()
{
if(form1.username.value=="")
{
alert("用户名不能为空!");
// 自己主动把焦点切换到username的输入框
form1.username.focus();
return false;
}
if(form1.password.value=="")
{
alert("密码不能为空!");
// 自己主动把焦点切换到password的输入框
form1.password.focus();
return false;
}
}
</script>
<html>
<head>
<title>请求表单</title>
</head>
<body>
<form action="acceptform.jsp" method="post" name="form1" onsubmit="return on_submit()">
<table style="margin:auto ;margin-top:200px" >
<tr>
<td colspan="2" align="center">请输入数据:</td>
</tr>
<tr>
<td>用户名:</td>
<td><input type="text" name="username"></td>
</tr>
<tr>
<td>密码:</td>
<td><input type="password" name="password"></td>
</tr>
<tr>
<td colspan="2" align="center"><input type="submit" value="提交"></td>
</tr>
</table>
</form>
</body>
</html>显示接收到的表单中的数据：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
<head>
<title>接收表单数据</title>
</head>
<body>
接收到的用户名:${param.username }<br>
接收到的密码:${param.password }
</body>
</html>
