下载文件

/**
     * 下载远程文件并保存到本地
     * 
     * @param remoteFilePath
     *            远程文件路径
     * @param localFilePath
     *            本地文件路径
     */
    public static void downloadFile(String remoteFilePath, String localFilePath) {
        URL urlfile = null;
        HttpURLConnection httpUrl = null;
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        File f = new File(localFilePath);
        try {
            urlfile = new URL(remoteFilePath);
            httpUrl = (HttpURLConnection) urlfile.openConnection();
            httpUrl.connect();
            bis = new BufferedInputStream(httpUrl.getInputStream());
            bos = new BufferedOutputStream(new FileOutputStream(f));
            int len = 2048;
            byte[] b = new byte[len];
            while ((len = bis.read(b)) != -1) {
                bos.write(b, 0, len);
                long fileLength = f.length();
                if (fileLength < 1024000) {
                    System.out.println("已下载：" + (f.length() / 1024.0) + "K");
                }else if (fileLength >= 1024000 && fileLength < 1024000000) {
                    System.out.println("已下载：" + (f.length() / 1024 / 1024.0) + "M");
                }else if (fileLength >= 1024000000 && fileLength < 1024000000000l) {
                    System.out.println("已下载：" + (f.length() / 1024 / 1024 / 1024.0) + "G");
                }
            }
            bos.flush();
            bis.close();
            httpUrl.disconnect();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                bis.close();
                bos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }