Android: Checking WiFi Connection

To be able to check WiFi connection in an Android application you first need to set the proper permission in the Android manifest:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.mytoolbox"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="9"
        android:targetSdkVersion="15" />

    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 
 ...
 
</manifest>

Here's a code to check the WiFi. If it's not on it shows an alert message indicating connection is required and then it finishes the application:

private void checkWiFiConnectivity() {
  ConnectivityManager connMan =  (ConnectivityManager) 
       getSystemService(Context.CONNECTIVITY_SERVICE);
  boolean wifiIsOn = connMan.getNetworkInfo(ConnectivityManager.TYPE_WIFI)
        .isConnectedOrConnecting();
  Log.d("GABO", "WiFi is : " + wifiIsOn);
  
  if(!wifiIsOn) {
   finishApplication();
  }  
}

private void finishApplication() {
  AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
  builder.setMessage("You need WiFi connection to access this App!");
  builder.setCancelable(false);
     
  builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
   
   @Override
   public void onClick(DialogInterface dialog, int which) {
       MainActivity.this.finish();    
   }
  });
     
  AlertDialog alert = builder.create();
  alert.show();  
}