static int fseek(InputStream fis, long off, int whence) {
        if (fis instanceof SeekableInputStream) {
            SeekableInputStream sis = (SeekableInputStream) fis;
            try {
                if (whence == SEEK_SET) {
                    sis.seek(off);
                } else if (whence == SEEK_END) {
                    sis.seek(sis.getLength() - off);
                } else {
                }
            } catch (Exception e) {
            }
            return 0;
        }
        try {
            if (whence == 0) {
                fis.reset();
            }
            fis.skip(off);
        } catch (Exception e) {
            return -1;
        }
        return 0;
    }