java中IP地址与long之间的转换

IP地址转为long型：

	public static long ipToLong(String ip) {
		String[] ipArray = ip.split("\\.");
		List ipNums = new ArrayList();
		for (int i = 0; i < 4; ++i) {
			ipNums.add(Long.valueOf(Long.parseLong(ipArray[i].trim())));
		}
		long ZhongIPNumTotal = ((Long) ipNums.get(0)).longValue() * 256L * 256L * 256L
				+ ((Long) ipNums.get(1)).longValue() * 256L * 256L + ((Long) ipNums.get(2)).longValue() * 256L
				+ ((Long) ipNums.get(3)).longValue();

		return ZhongIPNumTotal;
	}

long转为IP地址：

    public static String getIP(long ipaddr) { 
        long y = ipaddr % 256; 
        long m = (ipaddr - y) / (256 * 256 * 256); 
        long n = (ipaddr - 256 * 256 *256 * m - y) / (256 * 256); 
        long x = (ipaddr - 256 * 256 *256 * m - 256 * 256 *n - y) / 256; 
        return m + "." + n + "." + x + "." + y; 
    }

bytes to long：

    public static long bytes2Long(byte[] byteNum) {
        long num = 0;
        for (int ix = 0; ix < 8; ++ix) {
            num <<= 8;
            num |= (byteNum[ix] & 0xff);
        }
        return num;
    }