Getting IP address of local network using java

Question

I want to obtain the local IPv4 address of a user on their phone running my application when connected to a wifi network. Using the following code:

  WifiManager wm = (WifiManager) getApplicationContext().getSystemService(WIFI_SERVICE);
                    String ip = Formatter.formatIpAddress(wm.getConnectionInfo().getIpAddress());
                    hostname = ip;

I am able to get something close to the IPv4 address but when compared to the IPv4 address in the command line, it is not exactly the same. Is there a better way to go about this? I know that formatIpAddress is deprecated but until I find a way to get the IPv4 address I'm not too worried about that for now.

EDIT:

I have discovered that the ip address in the phone's wifi settings is what I am getting when using solutions to get the ip address like the suggested solutions. Is there any way to get the ip address in the ip config client side?

Answer 1

The following code traverse all the interface it has and then print the IPv4, IPv6 and mac address of the interface. For LAN IP address u can use a function isSiteLocal() which returns true if IP address is a local address.

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Enumeration;
public class App{

public static void main(String[] args)throws Exception {
    // getting the list of interfaces in the local machine
    Enumeration<NetworkInterface> n = NetworkInterface.getNetworkInterfaces();
    while( n.hasMoreElements()){ //for each interface
        System.out.println("----------------------------------------------------");
        NetworkInterface e = n.nextElement();
    //name of the interface
        System.out.println("Interface Name: " + e.getName());
    /* A interface may be binded to many IP addresses like IPv4 and IPv6
        hence getting the Enumeration of list of IP addresses  */
        Enumeration<InetAddress> a = e.getInetAddresses();
        while( a.hasMoreElements()){
            InetAddress addr = a.nextElement();
            String add = addr.getHostAddress().toString();
            if( add.length() < 17 )
                System.out.println("IPv4 Address: " + add);
            else
                System.out.println("IPv6 Address: " + add);
        }
        if(e.getHardwareAddress() != null){
                    // getting the mac address of the particular network interface
            byte[] mac = e.getHardwareAddress();
                    // properly formatting the mac address
            StringBuilder macAddress = new StringBuilder();
            for(int i =0; i < mac.length; i++){
                macAddress.append(String.format("%03X%s", mac[i],(i < mac.length -1) ? "-":""));
            }
            System.out.println("Hardware adrress: " + macAddress.toString());
        }
        System.out.println("----------------------------------------------------");
    }
}

}

The output of the code in kali linux 2.0 is:
----------------------------------------------------
Interface Name: wlan0
IPv6 Address: fe80:0:0:0:1992:d9bc:7d8c:d85b%wlan0
IPv4 Address: 192.168.1.137
Hardware adrress: 078-0E4-000-0E7-0B0-046
----------------------------------------------------
----------------------------------------------------
Interface Name: lo
IPv6 Address: 0:0:0:0:0:0:0:1%lo
IPv4 Address: 127.0.0.1
----------------------------------------------------

Answer 2

The code print the local IPv4 address of the device in which ur either Android or java application is running.

 try {
        Enumeration networkInterfaces = NetworkInterface.getNetworkInterfaces();  // gets All networkInterfaces of your device
        while (networkInterfaces.hasMoreElements()) {
            NetworkInterface inet = (NetworkInterface) networkInterfaces.nextElement();
            Enumeration address = inet.getInetAddresses();
            while (address.hasMoreElements()) {
                InetAddress inetAddress = (InetAddress) address.nextElement();
                if (inetAddress.isSiteLocalAddress()) {
                    System.out.println("Your ip: " + inetAddress.getHostAddress());  /// gives ip address of your device
                }
            }
        }
    } catch (Exception e) {
        // Handle Exception
    }