How to make a service to check wifi state?

Question

I am trying to make an app to lunch my main activity when wifi turns on. I found I should use a service to perform it. I found this code but does not work.

import android.app.IntentService;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.wifi.WifiManager;
import android.widget.Toast;

public class MyServer extends IntentService {
    public Boolean has_launched = false;
    public MyServer() {
        super("MyServer");
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Toast.makeText(MyServer.this, "service started", Toast.LENGTH_SHORT).show();
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        wificheck();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        return android.app.Service.START_STICKY;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Toast.makeText(MyServer.this, "service stoped!", Toast.LENGTH_SHORT).show();
    }

    public void wificheck() {
        WifiManager wifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
        if (wifi.isWifiEnabled() && has_launched == false) {
            has_launched = true;
            //startActivity(new Intent(MyServer.this, MainActivity.class));
            Toast.makeText(MyServer.this, "Wifi is on!", Toast.LENGTH_SHORT).show();
        }
        else if (wifi.isWifiEnabled() == false) {
            has_launched = false;
        }
    }
}

I have permission to read wifi state and the app lunch normally(without an error) It does not lunch wificheck. what should I do?

You need to do a little research before asking a question. This problem has been solved many times already http://stackoverflow.com/questions/3841317/how-to-see-if-wifi-is-connected-in-android — MobileMon, Jul 18 '14 at 14:37
Side note: `has_lunched == false` can be rewritten into `!has_lunched` and `wifi.isWifiEnabled() == false` into `!wifi.isWifiEnabled()`. Also, `to lunch` has a different meaning than `to launch` :) — stealthjong, Jul 18 '14 at 14:45
Please do some research before posting any question - http://android-er.blogspot.in/2011/01/detect-wifi-onoff-state.html — sjain, Jul 18 '14 at 14:45
dear @MobileMon my problem is using wifichecker in a service. I have searched a lot and I found this code. but it seems that onHandleIntent does not launch! — Mohammad H, Jul 18 '14 at 14:50
I want my started service launch my app when I turn on wifi adapter. — Mohammad H, Jul 18 '14 at 14:57

score 1 · Answer 1 · answered Jul 18 '14 at 14:37

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.widget.TextView;

public class AndroidWifiStateChangedDetect extends Activity {

TextView WifiState;

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
      WifiState = (TextView)findViewById(R.id.wifistate);

      this.registerReceiver(this.WifiStateChangedReceiver,
              new IntentFilter(WifiManager.WIFI_STATE_CHANGED_ACTION));
  }

  private BroadcastReceiver WifiStateChangedReceiver
  = new BroadcastReceiver(){

 @Override
 public void onReceive(Context context, Intent intent) {
  // TODO Auto-generated method stub

  int extraWifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE ,
    WifiManager.WIFI_STATE_UNKNOWN);

  switch(extraWifiState){
  case WifiManager.WIFI_STATE_DISABLED:
   WifiState.setText("WIFI STATE DISABLED");
   break;
  case WifiManager.WIFI_STATE_DISABLING:
   WifiState.setText("WIFI STATE DISABLING");
   break;
  case WifiManager.WIFI_STATE_ENABLED:
   WifiState.setText("WIFI STATE ENABLED");
   break;
  case WifiManager.WIFI_STATE_ENABLING:
   WifiState.setText("WIFI STATE ENABLING");
   break;
  case WifiManager.WIFI_STATE_UNKNOWN:
   WifiState.setText("WIFI STATE UNKNOWN");
   break;
  }

 }};
}

To detect Android Wifi ON/OFF (Enable/Disable) state, we can implement a BroadcastReceiver to register with the intent WifiManager.WIFI_STATE_CHANGED_ACTION. IN the BroadcastReceiver, the Wifi state can be retrieved using the code intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_UNKNOWN)

I want my started service launch my app when I turn on wifi adapter — Mohammad H, Jul 18 '14 at 15:02
WifiManager.WIFI_STATE_ENABLED this case can be useful for you — App Kart, Jul 18 '14 at 15:04

osayilgan · Answer 2 · 2014-07-18T15:50:04.530

As far as I remember, in Google I/O 2014, they introduced the new kind of Wifi State listener in OS level. So it's way more efficient in terms of battery life.

I don't remember which session it was. but either It is in "Key Note" or in "What's new in Android" video. You can check it out on YouTube.

I will update my answer when I come across this api.

EDIT :

I've found it. It's called JobScheduler. I'm not sure if it's all you need but worth to give it a try.

How to make a service to check wifi state?

2 Answers2