简单实现jsp输出文件

代码
<%@ page import="java.io.OutputStream" %>
<%--
  Created by IntelliJ IDEA.
  User: czy
  Date: 2010-3-31
  Time: 23:20:32
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=gbk" language="java" %>
<html>
<head><title>Simple jsp page</title></head>
<body>
<%
    String fileName = "hello.txt";response.setContentType("text/plain");
    response.setHeader("Location", fileName);
    response.setHeader("Content-Disposition", "attachment; filename=" + fileName);
    OutputStream outputStream = response.getOutputStream();
    String s = "hello world";
    byte[] buffer = new byte[1024];

    outputStream.write(s.getBytes());
    outputStream.flush();
    outputStream.close();
    out.clear();
    out=pageContext.pushBody();
%>
</body>
</html>