CRC32

CRC32.java

public static long getCRC32(String _source) throws UnsupportedEncodingException {
        int crc = 0xFFFFFFFF; // initial contents of LFBSR
        int poly = 0xEDB88320; // reverse polynomial
        byte[] bytes = _source.getBytes("utf-8");
        for (byte b : bytes) {
            int temp = (crc ^ b) & 0xff;

            // read 8 bits one at a time
            for (int i = 0; i < 8; i++) {
                if ((temp & 1) == 1)
                    temp = (temp >>> 1) ^ poly;
                else
                    temp = (temp >>> 1);
            }
            crc = (crc >>> 8 ^ temp);
        }
        // flip bits
        crc = crc ^ 0xffffffff;
        return UnsignedInteger.asUnsigned(crc).longValue();
    }