jspsmartupload下载用法

<%@ page contentType="text/html;charset=GBK"%>
<%@ page import="java.io.*" %>
<%
// 得到文件名字和路径
String filename = request.getParameter("filename");
String filepath = request.getSession().getServletContext().getgetRealPath("/download/excel/");
//String filepath = request.getRealPath("/download/excel/");
//读到流中
InputStream inputStream = new FileInputStream(filepath+"/"+filename);
//设置输出的格式
response.reset();
response.setContentType("bin");
response.addHeader("Content-Disposition","attachment;filename=\"" + filename + "\"");
//循环取出流中的数据
byte[] bytes = new byte[1000];
int len = inputStream.read(bytes);
while (len > 0){
 response.getOutputStream().write(bytes,0,len);
 len = inputStream.read(bytes);
}
inputStream.close();
%>