IP类型转换（String和int互相转换）

 //将127.0.0.1形式的IP地址转换成十进制整数，这里没有进行任何错误处理        public static long ipToLong(String strIp){            long[] ip = new long[4];            //先找到IP地址字符串中.的位置            int position1 = strIp.indexOf(".");            int position2 = strIp.indexOf(".", position1 + 1);            int position3 = strIp.indexOf(".", position2 + 1);            //将每个.之间的字符串转换成整型            ip[0] = Long.parseLong(strIp.substring(0, position1));            ip[1] = Long.parseLong(strIp.substring(position1+1, position2));            ip[2] = Long.parseLong(strIp.substring(position2+1, position3));            ip[3] = Long.parseLong(strIp.substring(position3+1));            return (ip[0] << 24) + (ip[1] << 16) + (ip[2] << 8) + ip[3];        }                //将十进制整数形式转换成127.0.0.1形式的ip地址        public static String longToIP(long longIp){            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)));            return sb.toString();        } 

 

 

public static void main(String[] args) throws ParseException {

String[] ipStrs = {"192.168.54.21","192.168.54.15","192.168.54.17","192.168.54.18","192.168.54.19","192.168.54.31"};         for (int i = 0; i < ipStrs.length; i++) {    String ipStri = ipStrs[i];    long longIp = ipToLong(ipStri);             System.out.println("192.168.0.1 的整数形式为：" + longIp);             System.out.println("整数" + longIp + "转化成字符串IP地址："                    + longToIP(longIp));    }

            

}