private void init( Headers h, long lastMod, long fileLength, String url, int blocksize, int[] hashLengths, String sha1) { h.version = "jazsync"; h.mTime = lastMod; h.url = url; h.length = fileLength; if (isPowerOfTwo(blocksize)) { h.blocksize = blocksize; } else { throw new IllegalArgumentException("Blocksize must be a power of 2 (512, 1024, 2048, ...)"); } h.setSeqNum(hashLengths[0]); h.setRsumBytes(hashLengths[1]); h.setChecksumBytes(hashLengths[2]); h.sha1 = sha1; }