Split the binaries every 8 digit with period java (android)-CodePudding

I'm getting this IP address

00000000111111110000000011111111

I want it to display like this

00000000.11111111.00000000.11111111

This is the code I tried

 String ipByte1=String.format("d", parseInt(ooct1));
            String ipByte2=String.format("d", parseInt(ooct2));
            String ipByte3=String.format("d", parseInt(ooct3));
            String ipByte4=String.format("d", parseInt(ooct4));

            //integer bitmask
            int bitmask= parseInt(String.valueOf(cidr.getText()));
            //32bit int from whole ip address
            int ipBin= parseInt(ipByte1 ipByte2 ipByte3,2);


            //32bit netmask bin
            int maskBin= ~0 << (32-bitmask);
            //and for network address
            int netBin=ipBin & maskBin;
            //or operation for Boradcast
            int bcBin=ipBin | ~maskBin;
            //splitting
            String strIpBin =Integer.toBinaryString(ipBin);

            String[] printIpBin=strIpBin.split("(?<=\\\\G........)");
            bad.setText(printIpBin[0] "." printIpBin[1] "." printIpBin[2] "." printIpBin[3]);

it throws

java.lang.ArrayIndexOutOfBoundsException: length=2; index=3

CodePudding user response：

use this regex pattern: "(?<=\\G.{8})"

public static void main (String[] args)
{
    String x = "00000000111111110000000011111111";
    int bits = 4;
    String[] results = x.split("(?<=\\G.{"   bits   "})");
    System.out.println("L: -> "  Arrays.asList(results));
}

outut:

Success #stdin #stdout 0.14s 50720KB

L: -> [0000, 0000, 1111, 1111, 0000, 0000, 1111, 1111]

CodePudding user response：

String Ip = ipByte1   "."   ipByte2   "."   ipByte3   "."   ipByte4;

will do or else:

String myIp = "00000000111111110000000011111111";

String myIp2 =  myIp.substring(0, 8 )
          "."   myIp.substring(8, 16)
          "."   myIp.substring(16, 24)
          "."   myIp.substring(24, 32)
        ;