How to create access point programmatically

Question

I've written the code to create an access point for android devices. I've tested on both emulator and real device.But it doesn't work. Where did i get wrong?

public class MainWAP extends Activity {

    WifiManager wifiManager;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_wap);
    }

    public void openWifi(View v) {
        createWifiAccessPoint();
    }

    private void createWifiAccessPoint() {
        if (wifiManager.isWifiEnabled()) {
            wifiManager.setWifiEnabled(false);
        }
        Method[] wmMethods = wifiManager.getClass().getDeclaredMethods();
        boolean methodFound = false;
        for (Method method: wmMethods) {
            if (method.getName().equals("setWifiApEnabled")) {
                methodFound = true;
                WifiConfiguration netConfig = new WifiConfiguration();
                netConfig.SSID = "AccessPoint";
                netConfig.allowedAuthAlgorithms.set(
                    WifiConfiguration.AuthAlgorithm.OPEN);
                try {
                    boolean apstatus = (Boolean) method.invoke(
                        wifiManager, netConfig, true);
                    for (Method isWifiApEnabledmethod: wmMethods) {
                        if (isWifiApEnabledmethod.getName().equals(
                                "isWifiApEnabled")) {
                            while (!(Boolean) isWifiApEnabledmethod.invoke(
                                    wifiManager)) {};
                            for (Method method1: wmMethods) {
                                if (method1.getName().equals(
                                        "getWifiApState")) {
                                    int apstate;
                                    apstate = (Integer) method1.invoke(
                                        wifiManager);
                                }
                            }
                        }
                    }
                    if (apstatus) {
                        Log.d("Splash Activity",
                            "Access Point created");
                    } else {
                        Log.d("Splash Activity",
                            "Access Point creation failed");
                    }

                } catch (IllegalArgumentException e) {
                    e.printStackTrace();
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                } catch (InvocationTargetException e) {
                    e.printStackTrace();
                }
            }
        }
        if (!methodFound) {
            Log.d("Splash Activity",
                "cannot configure an access point");
        }
    }
}

Are you getting some sort of related error message? Log message? — WilHall, Oct 17 '12 at 03:48
if you haven't done yet. Please check this out hope it might help you out : http://omtlab.com/android-check-network-connection-available-using-wifi/ @daniel — gumuruh, Aug 10 '14 at 14:50

Dmitry Zaytsev · Answer 1 · 2012-11-09T13:09:10.223

8

Your WiFiManager is definately not initialized.

In your onCreate method add this:

wifiManager = (WiFiManager) getSystemService(Context.WIFI_SERVICE);

edited Nov 09 '12 at 13:09

answered Nov 09 '12 at 12:36

Dmitry Zaytsev

23,650
14
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146

@Tom this is an answer to his question. If he'll initialize WiFiManager (and now it's `null`) everything will work fine (I've just tested it). – Dmitry Zaytsev Nov 09 '12 at 13:04
You just stated a fact. I think you should explain how it relates to the specific question and what should be done to solve the problem. There's a reason your answer has been automatically classified as low-quality. – toniedzwiedz Nov 09 '12 at 13:07
That's exactly what I mean. The post you replied to has been generated automatically by the review system. – toniedzwiedz Nov 09 '12 at 13:09
wifiManager = (WifiManager)this.getApplicationContext().getSystemService(Context.WIFI_SERVICE); // to prevent memory leak – Farshid Ahmadi Dec 25 '20 at 11:40

score 3 · Answer 2 · answered Apr 16 '13 at 12:18

3

You need few things to make this code to work.

1) Init wifiManager onCreate() :

WifiManager wifiManager = (WiFiManager) getSystemService(Context.WIFI_SERVICE);

2) You need to ask for this permissions in you AndroidManifest.xml :

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.WRITE_APN_SETTINGS" />

3) Your application need to be signed with system certificates.

answered Apr 16 '13 at 12:18

EvZ

11,889
4
38
76

3

What do you mean in step 3? – Rudolf Real Dec 28 '14 at 03:25
@FabricioPH He meant that it needs to be a system application, if you try to use `WRITE_APN_SETTINGS` it tells you that only system apps can use that permission. – JediBurrell Jul 19 '17 at 04:41

score 0 · Answer 3 · answered Oct 17 '12 at 04:30

0

With your method of exploiting undocumented APIs using reflection, things might not work well in all scenarios. Well, you can try adding these in your manifest file and give a try.

android.permission.ACCESS_WIFI_STATE
android.permission.CHANGE_WIFI_STATE
android.permission.WRITE_APN_SETTINGS

answered Oct 17 '12 at 04:30

Durairaj Packirisamy

4,635
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I've added in manifest file: android.permission.CHANGE_WIFI_STATE, android.permission.CHANGE_NETWORK_STATE, android.permission.INTERNET android.permission.ACCESS_NETWORK_STATE, android.hardware.wifi, android.permission.WRITE_APN_SETTINGS. But when i run in emulator and click on button, it pop-up force close. – daniel Oct 17 '12 at 07:21
In the log message it show: 1)caused by java.lang.reflect.InvocationTargetException 2)caused by java.lang.NullPointerException – daniel Oct 17 '12 at 07:32
1) Caused by java.lang.reflect.InvocationTargetException at line 27: `createWifiAccessPoint();` 2) Caused by java.lang.NullPointerException at line 33: `if(wifiManager.isWifiEnabled())` @WilHall – daniel Oct 17 '12 at 08:11

How to create access point programmatically

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