jsp下载

	public ActionForward dnowload(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
				
		OutputStream out;
		InputStream in;

//		获取filename请求参数
		String filename = request.getParameter("fileNames");

		if (filename == null)
		{
			out = response.getOutputStream();
			out.write("Please input filename.".getBytes());
			out.close();
			return null;
		}

//		获得读取本地文件的输入流
		in=new FileInputStream("f:\\upload\\"+filename);
		int length= in.available();

//		设置喷响应正文的MIMI类型
		response.setContentType("application/force-download");
		response.setHeader("Content-Length", String.valueOf(length));
		response.setHeader("Content-Disposition", "attachment;filename=\"" +filename + "\" ");

//		把本地文件中的数据发送给客户
		out=response.getOutputStream();
		int bytesRead = 0;
		byte[] buffer = new byte[512];
		while ((bytesRead = in.read(buffer))!=-1)
		{
		out.write(buffer, 0, bytesRead);
		}

		in.close();
		out.close();
		
		return null;
	}