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How to get the ip of the computer on linux through Java?

Asked 2009-05-23T15:35:14.593
12

How to get the ip of the computer on linux through Java ?

I searched the net for examples, I found something regarding NetworkInterface class, but I can't wrap my head around how I get the Ip address.

What happens if I have multiple network interfaces running in the same time ? Which Ip address will be returned.

I would really appreciate some code samples.

P.S: I've used until now the InetAddress class which is a bad solution for cross-platform applications. (win/Linux).

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13

From Java Tutorial

Why is InetAddress not a good solution? I don't see anything in the docs about cross platform compatibility?

This code will enumerate all network interfaces and retrieve their information.

import java.io.*;
import java.net.*;
import java.util.*;
import static java.lang.System.out;

public class ListNets 
{
    public static void main(String args[]) throws SocketException {
        Enumeration<NetworkInterface> nets = NetworkInterface.getNetworkInterfaces();
        for (NetworkInterface netint : Collections.list(nets))
            displayInterfaceInformation(netint);
    }

    static void displayInterfaceInformation(NetworkInterface netint) throws SocketException {
        out.printf("Display name: %s\n", netint.getDisplayName());
        out.printf("Name: %s\n", netint.getName());
        Enumeration<InetAddress> inetAddresses = netint.getInetAddresses();
        for (InetAddress inetAddress : Collections.list(inetAddresses)) {
            out.printf("InetAddress: %s\n", inetAddress);
        }
        out.printf("\n");
     }
}  

The following is sample output from the example program:

Display name: bge0
Name: bge0
InetAddress: /fe80:0:0:0:203:baff:fef2:e99d%2
InetAddress: /121.153.225.59

Display name: lo0
Name: lo0
InetAddress: /0:0:0:0:0:0:0:1%1
InetAddress: /127.0.0.1

answered 2009-05-23T15:45:32.830

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