java 判断字符串IP合法性以及获取IP的数值形式

　　/**
     * 计算传入的IP地址的数字IP*/
    public static long getIpNum(String ip) {
        long ipNum = 0;
        if (StringUtils.isNotBlank(ip) && isIP(ip)) {
            String[] spstr_IP = ip.split("\.");
            ipNum = Long.parseLong(spstr_IP[0]) * 256 * 256 * 256 + Long.parseLong(spstr_IP[1]) * 256 * 256 + Long.parseLong(spstr_IP[2]) * 256 + Long.parseLong(spstr_IP[3]);
        }
        return ipNum;
    }
    
    /**
     * 判断是否是合法的IP地址*/
    public static boolean isIP(String ip){
        Pattern ipPattern=Pattern.compile("([1-9]|[1-9]\d|1\d{2}|2[0-1]\d|22[0-3])(\.(\d|[1-9]\d|1\d{2}|2[0-4]\d|25[0-5])){3}");
        Matcher matcher=ipPattern.matcher(ip);
        return matcher.matches();
    }