ip与掩码处理

1.ip转char

下列程序有两个实用功能：

1.ip转32位char []

2.给一个ip和一对<ip,掩码>，判断是否命中。

class WhiteIpMask {
	public static Set set = new HashSet<>();
	public String ip;
	public int mask;

	public WhiteIpMask(String ip, int mask) {
		this.ip = ip;
		this.mask = mask;
	}

	static boolean add(WhiteIpMask e) {
		return set.add(e);
	}

	public static boolean isInWhiteList(String ip) {
		for (WhiteIpMask e : set)
			if (isInWhiteList(e, ip))
				return true;
		return false;
	}

	static boolean isInWhiteList(WhiteIpMask e, String ip) {
		char[] whiteIpArr = strToCharArr(e.ip);
		int mask = e.mask;
		char[] ipArr = strToCharArr(ip);
		for (int i = 0; i < mask; i++)
			if (whiteIpArr[i] != ipArr[i])
				return false;
		return true;

	}

	/**
	 * @param x
	 *            3
	 * @return 00000011
	 */
	public static String intTo8BitBin(int x) {
		String str = Integer.toBinaryString(x);
		char zero[] = { '0', '0', '0', '0', '0', '0', '0', '0' };
		return new String(zero, 0, 8 - str.length()) + str;
	}

	/**
	 * @param ipStr
	 *            1.2.3.4
	 * @return 00000001 00000010 00000011 00000100
	 */
	public static char[] strToCharArr(String ipStr) {
		String strArr[] = ipStr.split("\\.");
		int a = Integer.valueOf(strArr[0]);
		int b = Integer.valueOf(strArr[1]);
		int c = Integer.valueOf(strArr[2]);
		int d = Integer.valueOf(strArr[3]);
		return (intTo8BitBin(a) + intTo8BitBin(b) + intTo8BitBin(c) + intTo8BitBin(d))
				.toCharArray();
	}
}

2.ip转long

 long ipv4ToLong(String ip) {
        String[] parts = ip.split("\\.");
        return (Long.parseLong(parts[0]) << 24) | (Long.parseLong(parts[1]) << 16) | (Long.parseLong(parts[2]) << 8) | (Long.parseLong(parts[3]))
    }