Convert IP between IPv4 and numerical format in java

Question

An IPv4 can have more representations: as string (a.b.c.d) or numerical (as an unsigned int of 32 bits). (Maybe other, but I will ignore them.)

Is there any built in support in Java (8), simple and easy to use, without network access, to convert between these formats?

I need something like this:

long ip = toNumerical("1.2.3.4"); // returns 0x0000000001020304L
String ipv4 = toIPv4(0x0000000001020304L); // returns "1.2.3.4"

If there is no built in such functions in Java, feel free to suggest other solutions.

Thank you

Answer 1

The can be done using InetAddress as follows.

   //Converts a String that represents an IP to an int.
   InetAddress i= InetAddress.getByName(IPString);
   int intRepresentation= ByteBuffer.wrap(i.getAddress()).getInt();

   //This convert an int representation of ip back to String
   i= InetAddress.getByName(String.valueOf(intRepresentation));
   String ip= i.getHostAddress();