servlet文件下载

protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String path = this.getServletContext().getRealPath("/download/a.jpg");
        String filename = path.substring(path.lastIndexOf("\\") + 1);

        response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(filename, "UTF-8"));

        InputStream in = new FileInputStream(path);
        OutputStream out = response.getOutputStream();

        //注意这里要try..catch
        int len = 0;
        byte buffer[] = new byte[1014];
        while ((len = in.read(buffer)) != -1) {
            out.write(buffer, 0, len);
        }
    }