Test for Network Connection Before Activity Runs in Android

android-network-check

try{
	if (isOnline()){
		// Activity Stuff Goes Here
	} else {
		Log.d("Connection Status", "Connection Not Available");
		    	
		AlertDialog alertDialog = new AlertDialog.Builder(this).create();
		alertDialog.setTitle("No Network Connection");
		alertDialog.setMessage("Internet access is necessary for the use of this app.");
		alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
			public void onClick(DialogInterface dialog, int which) {
				// here you can add functions
			}
		});
		alertDialog.show();
	}
} catch(NullPointerException e){
	    	Log.d("Connection Status", "Connection Not Available");
	    	
	    	AlertDialog alertDialog = new AlertDialog.Builder(this).create();
	    	alertDialog.setTitle("No Network Connection");
	    	alertDialog.setMessage("Internet access is necessary for the use of this app.");
	    	alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
	    	   public void onClick(DialogInterface dialog, int which) {
	    	      // here you can add functions
	    	   }
	    	});
	    	alertDialog.show();
	    }


public boolean isOnline() {
		ConnectivityManager connectionManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
		try {
			if (connectionManager.getActiveNetworkInfo().isConnected()) {
				Log.d("ConStatus", "Data Connection On");
				return true;
			} else {
				Log.d("ConStatus", "Data Connection off");
				return false;			
			}
		} catch (NullPointerException e) {
			// No Active Connection
			Log.i("ConStatus", "No Active Connection");
			return false;
		}
	}