http://stackoverflow.com/questions/8324215/ip-address-of-device-using-phone-as-access-point

 

The following code will give you the ip adrress & other details of the wifi enabled devices connected to the the android hotspot device

 

Main.java

 

import java.util.ArrayList;import android.app.Activity;import android.os.Bundle;import android.widget.TextView;import com.whitebyte.hotspotclients.R;import com.whitebyte.wifihotspotutils.ClientScanResult;import com.whitebyte.wifihotspotutils.WifiApManager;public class Main extends Activity {      TextView textView1;      WifiApManager wifiApManager;/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.main);    textView1 = (TextView) findViewById(R.id.textView1);    wifiApManager = new WifiApManager(this);    scan();}private void scan() {    ArrayList
     
       clients = wifiApManager.getClientList(false);    textView1.append("Clients: \n");    for (ClientScanResult clientScanResult : clients) {        textView1.append("####################\n");        textView1.append("IpAddr: " + clientScanResult.getIpAddr() + "\n");        textView1.append("Device: " + clientScanResult.getDevice() + "\n");        textView1.append("HWAddr: " + clientScanResult.getHWAddr() + "\n");        textView1.append("isReachable: " + clientScanResult.isReachable() + "\n");    }}
     

ClientScanResult.java

public class ClientScanResult {private String IpAddr;private String HWAddr;private String Device;private boolean isReachable;public ClientScanResult(String ipAddr, String hWAddr, String device, boolean isReachable) {    super();    IpAddr = ipAddr;    HWAddr = hWAddr;    Device = device;    this.setReachable(isReachable);}public String getIpAddr() {    return IpAddr;}public void setIpAddr(String ipAddr) {    IpAddr = ipAddr;}public String getHWAddr() {    return HWAddr;}public void setHWAddr(String hWAddr) {    HWAddr = hWAddr;}public String getDevice() {    return Device;}public void setDevice(String device) {    Device = device;}public void setReachable(boolean isReachable) {    this.isReachable = isReachable;}public boolean isReachable() {    return isReachable;}

 

WIFI_AP_STATE.java

 

public enum WIFI_AP_STATE      {        WIFI_AP_STATE_DISABLING, WIFI_AP_STATE_DISABLED, WIFI_AP_STATE_ENABLING, WIFI_AP_STATE_ENABLED, WIFI_AP_STATE_FAILED     }

 

WifiApManager.java

import java.io.BufferedReader;import java.io.FileReader;import java.io.IOException;import java.lang.reflect.Method;import java.net.InetAddress;import java.util.ArrayList;import android.content.Context;import android.net.wifi.WifiConfiguration;import android.net.wifi.WifiManager;import android.util.Log;public class WifiApManager {private final WifiManager mWifiManager;public WifiApManager(Context context) {    mWifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);}/** * Gets a list of the clients connected to the Hotspot, reachable timeout is 300 * @param onlyReachables {
    @code false} if the list should contain unreachable (probably disconnected) clients, {
    @code true} otherwise * @return ArrayList of {
    @link ClientScanResult} */public ArrayList
     
       getClientList(boolean onlyReachables) {    return getClientList(onlyReachables, 300);}/** * Gets a list of the clients connected to the Hotspot  * @param onlyReachables {
    @code false} if the list should contain unreachable (probably disconnected) clients, {
    @code true} otherwise * @param reachableTimeout Reachable Timout in miliseconds * @return ArrayList of {
    @link ClientScanResult} */public ArrayList
      
        getClientList(boolean onlyReachables, int reachableTimeout) {    BufferedReader br = null;    ArrayList
       
         result = null;    try {        result = new ArrayList
        
         ();        br = new BufferedReader(new FileReader("/proc/net/arp"));        String line;        while ((line = br.readLine()) != null) {            String[] splitted = line.split(" +");            if ((splitted != null) && (splitted.length >= 4)) {                // Basic sanity check                String mac = splitted[3];                if (mac.matches("..:..:..:..:..:..")) {                    boolean isReachable = InetAddress.getByName(splitted[0]).isReachable(reachableTimeout);                    if (!onlyReachables || isReachable) {                        result.add(new ClientScanResult(splitted[0], splitted[3], splitted[5], isReachable));                    }                }            }        }    } catch (Exception e) {        Log.e(this.getClass().toString(), e.getMessage());    } finally {        try {            br.close();        } catch (IOException e) {            Log.e(this.getClass().toString(), e.getMessage());        }    }    return result;}}