1.计算文件大小，并按**B,*KB，**MB，**GB格式返回字符串

/**
     * 文件大小格式转换
     * @param fileS 文件大小
     * @return 文件大小
     */
    public static String FormetFileSize(long fileS) 
    {
        // 转换文件大小
        DecimalFormat df = new DecimalFormat("#.00");
        String fileSizeString = "";
        if (fileS < 1024) 
        {
            fileSizeString = df.format((double) fileS) + "B";
        } 
        else if (fileS < 1048576) 
        {
            fileSizeString = df.format((double) fileS / 1024) + "KB";
        } 
        else if (fileS < 1073741824) 
        {
            fileSizeString = df.format((double) fileS / 1048576) + "MB";
        } 
        else 
        {
            fileSizeString = df.format((double) fileS / 1073741824) + "GB";
        }
        return fileSizeString;
    }

2.毫秒转换为h:mm:ss字符串格式方法
  
 1  private String stringForTime(int timeMs) {
 2          int totalSeconds = timeMs / 1000;
 3          int seconds = totalSeconds % 60;
 4          int minutes = (totalSeconds / 60) % 60;
 5          int hours   = totalSeconds / 3600;
 6          if (hours > 0) {
 7              return String.format("%d:%02d:%02d", hours, minutes, seconds);
 8          } else {
 9              return String.format("%02d:%02d", minutes, seconds);
10          }
11      }