java下载文件

/**
     * 
     * @param file
     * @param response
     */
    private void downLoad(File file, HttpServletResponse response,
            String browser) throws IOException {
        InputStream is = new FileInputStream(file);
        try {

            String fileName = file.getName().replaceAll(" ", "");
            OutputStream os = response.getOutputStream();
            BufferedInputStream bis = new BufferedInputStream(is);
            BufferedOutputStream bos = new BufferedOutputStream(os);

            if (browser.indexOf("msie") != -1) {
                fileName = java.net.URLEncoder.encode(fileName, "UTF-8");
                fileName = new String(fileName.getBytes("UTF-8"), "GBK");
            } else if (browser.indexOf("Firefox") != -1) {
                fileName = java.net.URLEncoder.encode(fileName, "UTF-8");
                fileName = new String(fileName.getBytes("UTF-8"), "ISO8859-1");
            } else if (browser.indexOf("Safari") != -1) {
                fileName = new String(fileName.getBytes(), "ISO8859-1");
            }

            response.reset();
            response.setCharacterEncoding("UTF-8");
            response.setContentType("application/x-msdownload");
            response.setHeader("Content-Disposition", "attachment; filename="
                    + fileName);
            int bytesRead = 0;
            byte[] buffer = new byte[1024];
            while ((bytesRead = bis.read(buffer)) != -1) {
                bos.write(buffer, 0, bytesRead);
            }

            bos.flush();
            bis.close();
            bos.close();

            is.close();

            os.close();

        } catch (Exception ex) {

            log.info("");

        } finally {
            is.close();
        }
    }