public class crc64 {

private static final long INITIALCRC = 0xFFFFFFFFFFFFFFFFL;

private static long[] sCrcTable = new long[256];

private static final long POLY64REV = 0x95AC9329AC4BC9B5L;

static {

// http://bioinf.cs.ucl.ac.uk/downloads/crc64/crc64.c

long part;

for (int i = 0; i < 256; i++) {

part = i;

for (int j = 0; j < 8; j++) {

long x = ((int) part & 1) != 0 ? POLY64REV : 0;

part = (part >> 1) ^ x;

}

sCrcTable[i] = part;

}

}

public static final long crc64Long(String in) {

if (in == null || in.length() == 0) {

return 0;

}

return crc64Long(getBytes(in));

}

// 将String转换成字节数组

public static byte[] getBytes(String in) {

byte[] result = new byte[in.length() * 2];// 一个字符占两个字节

int output = 0;

for (char ch : in.toCharArray()) {

result[output++] = (byte) (ch & 0xFF);// 取低8位

result[output++] = (byte) (ch >> 8);// 取高8位

}

return result;

}

// crc64