一. JAVA代码：
request.setAttribute("mes", "上传成功");
request.getRequestDispatcher("success.jsp").forward(request, response);二. JSP页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="java.io.*,java.util.*" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>${mes}</title>
</head>
<body>
<h1>${mes}</h1>
<h2><% out.print(request.getAttribute("mes"));%></h2>
<h2><% out.print(request.getParameter("mes")); %></h2>
</body>
</html>