Reputation: 6585

Wifi information in Java

How can I get the MAC address, SSID, and signal strength of wifi routers nearby in Java? Preferably system independent, if not then Windows.

Upvotes: 3

Answers (3)

Rajind Ruparathna

Reputation: 2255

I know this is a very old question but you can use netsh commands in Windows to extract wifi information using java. Here is a blog post I made regarding that. https://notebookbft.wordpress.com/2015/11/25/wifi-information-extraction-java/

Java doesn’t allows us to directly get that low level information. Therefore I had run command line and run netsh commands inside java an extract that information. Following is the class I implemented for this. Please note that this only works on windows.

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author Rajind
 */
public class Extractor {

    public static String NOT_SET = "NOT_SET";

    public static boolean isEnabled(){
        try {
            String state;
            ProcessBuilder builder = new ProcessBuilder(
                    "cmd.exe", "/c", "netsh interface show interface \"Wi-Fi\"");
            builder.redirectErrorStream(true);
            Process p = builder.start();
            BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line;
            while ((line = r.readLine())!=null) {
                //line = r.readLine();
                if (line.contains("Administrative state")){
                    state = line.split("\\s+")[3];
                    //System.out.println(state);
                    state = state.toLowerCase();
                    if(state.equals("enabled")){
                        return true;
                    }else{
                        return false;
                    }
                }
            }
        } catch (IOException ex) {
            Logger.getLogger(Extractor.class.getName()).log(Level.SEVERE, null, ex);
        }
        return false;
    }

    public static boolean isConnected(){
        try {
            String state;
            ProcessBuilder builder = new ProcessBuilder(
                    "cmd.exe", "/c", "netsh interface show interface \"Wi-Fi\"");
            builder.redirectErrorStream(true);
            Process p = builder.start();
            BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line;
            while ((line = r.readLine())!=null) {
                //line = r.readLine();
                if (line.contains("Connect state")){
                    state = line.split("\\s+")[3];
//                    System.out.println(state);
                    state = state.toLowerCase();
                    if(state.equals("connected")){
                        return true;
                    }else{
                        return false;
                    }
                }
            }
        } catch (IOException ex) {
            Logger.getLogger(Extractor.class.getName()).log(Level.SEVERE, null, ex);
        }
        return false;
    }

    public static String getConnectedSSID(){
        String ssid = NOT_SET;
        try {
            ProcessBuilder builder = new ProcessBuilder(
                    "cmd.exe", "/c", "netsh wlan show interfaces");
            builder.redirectErrorStream(true);
            Process p = builder.start();
            BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line;
            while ((line = r.readLine())!=null) {
                //line = r.readLine();
                if (line.contains("SSID")){
                    ssid = line.split("\\s+")[3];
//                    System.out.println(ssid);
                    return ssid;
                }
            }
        } catch (IOException ex) {
            Logger.getLogger(Extractor.class.getName()).log(Level.SEVERE, null, ex);
        }
        return ssid;
    }

    public static String[] getListOfSSIDs(){
        String [] ssid_List;
        String ssid;
        ArrayList<String> arr = new ArrayList<>();
        try {
            ProcessBuilder builder = new ProcessBuilder(
                    "cmd.exe", "/c", "netsh wlan show networks");
            builder.redirectErrorStream(true);
            Process p = builder.start();
            BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line;
            while ((line = r.readLine())!=null) {
                //line = r.readLine();
                if (line.contains("SSID")){
                    ssid = line.split("\\s+")[3];
                    //System.out.println(ssid);
                    arr.add(ssid);
                }
            }
        } catch (IOException ex) {
            Logger.getLogger(Extractor.class.getName()).log(Level.SEVERE, null, ex);
        }
        ssid_List = new String[arr.size()];
        arr.toArray(ssid_List);
        return ssid_List;
    }

    public static String getIP(){
        String ip = NOT_SET; 
        try {
            ProcessBuilder builder = new ProcessBuilder(
                    "cmd.exe", "/c", "netsh interface ip show addresses \"Wi-Fi\"");
            builder.redirectErrorStream(true);
            Process p = builder.start();
            BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line;
            while ((line = r.readLine())!=null) {
                //line = r.readLine();
                if (line.contains("IP Address")){
                    ip = line.split("\\s+")[3];
                    //System.out.println(ip);
                    return ip;
                }
            }
        } catch (IOException ex) {
            Logger.getLogger(Extractor.class.getName()).log(Level.SEVERE, null, ex);
        }
        return ip;
    }

    public static String getSubnetMask(){
        String sb = NOT_SET; 
        try {
            ProcessBuilder builder = new ProcessBuilder(
                    "cmd.exe", "/c", "netsh interface ip show addresses \"Wi-Fi\"");
            builder.redirectErrorStream(true);
            Process p = builder.start();
            BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line;
            while ((line = r.readLine())!=null) {
                //line = r.readLine();
                if (line.contains("Subnet Prefix")){
                    sb = line.split("\\s+")[5];
                    sb = sb.substring(0, sb.length() - 1);
                    //System.out.println(sb);
                    return sb;
                }
            }
        } catch (IOException ex) {
            Logger.getLogger(Extractor.class.getName()).log(Level.SEVERE, null, ex);
        }
        return sb;
    }

    public static String getBroadcast(){
        String subnetMask = getSubnetMask();
        String ip = getIP();

        String []arrSubnetMask = subnetMask.split("\\.");
        String []arrIP = ip.split("\\.");
        int []networkAddress = new int[4];
        int [] broadcastAddress = new int[4];

        String broadcast = "";

        for(int i=0; i< 4; i++){
            networkAddress[i] =  Integer.parseInt(arrIP[i]) & Integer.parseInt(arrSubnetMask[i]);
            //System.out.println(networkAddress[i]);
        }

        for(int i=0; i< 4; i++){
            //broadcastAddress[i] =  networkAddress[i] | (~Integer.parseInt(arrSubnetMask[i]) & 0xff);
            //System.out.println(broadcastAddress[i]);
            broadcast = broadcast + "." + (networkAddress[i] | (~Integer.parseInt(arrSubnetMask[i]) & 0xff));
        }

//        System.out.println(broadcast.substring(1));

        //mask AND ip you get network address
        //Invert Mask OR Network Address you get broadcast

        return broadcast.substring(1);
    }
}

Upvotes: 0