以下程序是實現一個簡單的留言板：
<%@ page language="java" import="java.util.*" pageEncoding="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>
<table>
<%
if(request.getParameter("submit") != null)
{
String user = new String(request.getParameter("user").getBytes("ISO-8859-1"),"UTF-8");
String title = new String(request.getParameter("title").getBytes("ISO-8859-1"),"UTF-8");
String content = new String(request.getParameter("content").getBytes("ISO-8859-1"),"UTF-8");
java.util.Vector vector = (java.util.Vector)application.getAttribute("note");
if(vector == null)
vector = new java.util.Vector();
vector.add(user);
vector.add(title);
vector.add(content);
application.setAttribute("note",vector);
}
if(application.getAttribute("note") != null){
java.util.Vector vector = (java.util.Vector)application.getAttribute("note");
for(int i = 0;vector != null && i < vector.size();i = i + 3){
%>
<tr>
<td>用戶</td><td><input type="text" size="10" name="user" value="<%=vector.get(i).toString() %>"/></td>
</tr>
<tr><td>標題</td><td><input type="text" size="10" name="title" value="<%=vector.get(i+1).toString() %>"/></td></tr>
<tr><td>內容</td><td><textarea width="100px" height="100px" name="content"><%=vector.get(i+2).toString() %></textarea></td></tr>
<%
}}
if(request.getParameter("clear") != null)
application.removeAttribute("note");
%>
</table>
<div>
<form>
<table border="1">
<tr><td colspan="2" align="center">留言版</td></tr>
<tr>
<td>用戶</td><td><input type="text" size="10" name="user" /></td>
</tr>
<tr><td>標題</td><td><input type="text" size="10" name="title" /></td></tr>
<tr><td>內容</td><td><textarea name="content" width="100px" height="100px"></textarea></td></tr>
<tr><td colspan="2" align="center"><input type="submit" size="10" value="OK" name="submit"/>
<input type="submit" value="clear" name="clear"/></td></tr>
</table>
</form>
</div>
</body>
</html>