Constructing an InetAddress from a byte[]

[Dillinger4]

After reading a question on this topic over at jguru i tried to figure out how an InetAddress object could be constructed using an ip address in the form of a byte[].

Figuring the ip address is most likely a String(say if a host is resolved to an IpAddress) i tried to construct a byte array to make another InetAddress object but the code simply fails because the byte array is too long.

InetAddress inet = InetAddress.getByName("www.sun.com");
String ip = inet.getHostAddress();
System.out.println(ip);
InetAddress inet2 = InetAddress.getByAddress(ip.getBytes());
System.out.println(inet2.getHostAddress());

Even hardcoding the values of the ip address into a byte[] wouldn't work since java dosen't have unsigned primative types.

[System_Error]

use getAddress to get the bytes:

import java.net.*;

class Testing
{
	public static void main(String[] args) throws Exception
	{
		InetAddress inet = InetAddress.getByName("www.sun.com");	
		byte[] ip = inet.getAddress();
		InetAddress inet2 = InetAddress.getByAddress(ip);
		System.out.println(inet2.getHostAddress()); 
	}
}

[Dillinger4]

Works. Now getAddress() returns a byte[] but that's only from a InetAddress object that has been created already. So what would we do without it?

 InetAddress inet = InetAddress.getByName("www.sun.com");
 System.out.println(inet.getHostName()); 
 System.out.println(inet.getHostAddress()); 
 InetAddress inet2 = InetAddress.getByAddress(inet.getAddress());
 System.out.println(inet2.getHostName()); 
 System.out.println(inet2.getHostAddress());

[System_Error]

So your wanting to get the IP Address without an InetAddress object to read the bytes from? If so, I don't think it's possible. I've looked into the URL class, but it doesn't have anything, even though it does support the ipaddress as an argument. The only other way I can think of is getting some external process:

Process p = Runtime.Runtime().exec("ipconfig");

Maybe somehow you could get it using net commands.

[Dillinger4]

Posted by System_Error

Maybe somehow you could get it using net commands.

Perhaps. Ill have to look into it. Thanks for the help.

[CornedBee]

What exactly is wrong with using an InetAddress?

[Dillinger4]

hugh?

[CornedBee]

Why do you need to construct an InetAddress from a byte[] that comes from who-knows-where?

[Dillinger4]

It was a question that was asked by someone. Why they would want to i have no idea.