ipv4地址，数字转字符串，字符串转数字

package com.zjl.utils;

import com.zjl.exception.BusinessException;
import org.apache.commons.lang3.StringUtils;

public class IpAddressUtils {
private static final String IPV4_REGEX = "\b(?😦?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b";
/**
* 字符串ip转数字
*/
public static Long strIpToLong(String ipStr) {
long[] ip = new long[4];
//先找到IP地址字符串中.的位置
int position1 = ipStr.indexOf(".");
int position2 = ipStr.indexOf(".", position1 + 1);
int position3 = ipStr.indexOf(".", position2 + 1);
//将每个.之间的字符串转换成整型
ip[0] = Long.parseLong(ipStr.substring(0, position1));
ip[1] = Long.parseLong(ipStr.substring(position1+1, position2));
ip[2] = Long.parseLong(ipStr.substring(position2+1, position3));
ip[3] = Long.parseLong(ipStr.substring(position3+1));
return (ip[0] << 24) + (ip[1] << 16) + (ip[2] << 8) + ip[3];
}

/**
 * 数字ip转字符串
 */
public static String longIpToStr(Long longIp) throws BusinessException {
    StringBuffer sb = new StringBuffer("");
    //直接右移24位
    sb.append(String.valueOf((longIp >>> 24)));
    sb.append(".");
    //将高8位置0，然后右移16位
    sb.append(String.valueOf((longIp & 0x00FFFFFF) >>> 16));
    sb.append(".");
    //将高16位置0，然后右移8位
    sb.append(String.valueOf((longIp & 0x0000FFFF) >>> 8));
    sb.append(".");
    //将高24位置0
    sb.append(String.valueOf((longIp & 0x000000FF)));
    if (isValidIp(sb.toString())) {
        return sb.toString();
    } else {
        throw new BusinessException("这不是一个合规的ipv4地址");
    }
}

/**
 * ipv4地址合法性校验
 */
public static boolean isValidIp(String ipStr) {
    if (ipStr != null && StringUtils.isNotEmpty(ipStr)) {
        return ipStr.matches(IPV4_REGEX);
    } else {
        return false;
    }
}

}