Android: How to send sms with particular SIM in dual sim mobiles?

I found some code to do this, but It's giving me an exception ( Attempt to invoke virtual method 'java.lang.Class java.lang.Object.getClass()' on a null object reference). I am testing with my Moto G 3rd Gen. Below is the code, Please let me know if I am missing anything or any other approach are available. Thank you.

import android.app.PendingIntent;
import android.content.Context;
import android.os.IBinder;
import android.util.Log;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;


public class SimUtil {

    private static final String TAG = "SimUtil";

    public static boolean sendSMS(Context ctx, int simID, String toNum, String centerNum, String smsText, PendingIntent sentIntent, PendingIntent deliveryIntent) {

       SimUtil cls = new SimUtil();

        String name;

        try {
            if (simID == 0) {
                name = "isms";

            } else if (simID == 1) {
                name = "isms2";

            } else {
                throw new Exception("can not get service which for sim '" + simID + "', only 0,1 accepted as values");
            }

            try
            {
                Method method = Class.forName("android.os.ServiceManager").getDeclaredMethod("getService", new Class[]{String.class});
                method.setAccessible(true);
                Object param = method.invoke(null, new Object[]{name});

                if (param == null)
                {
                    throw new RuntimeException("can not get service which is named '" + name + "'");
                }
                method = Class.forName("com.android.internal.telephony.ISms$Stub").getDeclaredMethod("asInterface", new Class[]{IBinder.class});
                method.setAccessible(true);
                Object stubObj = method.invoke(null, new Object[]{param});

                if (stubObj == null)
                {
                    throw new RuntimeException("can not get telephony which is named '" + name + "'");
                }


                method = stubObj.getClass().getMethod("sendText", String.class, String.class, String.class, String.class, PendingIntent.class, PendingIntent.class);

                method.invoke(null, new Object[]{ctx.getPackageName(), toNum, null, smsText, sentIntent, deliveryIntent});


            } catch (ClassNotFoundException e)
            {
                throw new RuntimeException(e);
            } catch (NoSuchMethodException e)
            {
                throw new RuntimeException(e);
            } catch (InvocationTargetException e)
            {
                throw new RuntimeException(e);
            } catch (IllegalAccessException e)
            {
                throw new RuntimeException(e);
            }

            return true;
        } catch (ClassNotFoundException e) {
            Log.e("Exception", "ClassNotFoundException:" + e.getMessage());
        } catch (NoSuchMethodException e) {
            Log.e("Exception", "NoSuchMethodException:" + e.getMessage());
        } catch (InvocationTargetException e) {
            Log.e("Exception", "InvocationTargetException:" + e.getMessage());
        } catch (IllegalAccessException e) {
            Log.e("Exception", "IllegalAccessException:" + e.getMessage());
        } catch (Exception e) {
            Log.e("Exception", "Exception:" + e);
        }
        return false;
    }

If you're targeting API 22 or higher. You can use the following code to get the list of SIM Cards. You can also allow user to choose the SIM Card:

final ArrayList<Integer> simCardList = new ArrayList<>();
SubscriptionManager subscriptionManager;
subscriptionManager = SubscriptionManager.from(activity);
final List<SubscriptionInfo> subscriptionInfoList = subscriptionManager
                    .getActiveSubscriptionInfoList();
for (SubscriptionInfo subscriptionInfo : subscriptionInfoList) {
    int subscriptionId = subscriptionInfo.getSubscriptionId();
    simCardList.add(subscriptionId);
}

Finally send the SMS using following code:

int smsToSendFrom = simCardList.get(0); //assign your desired sim to send sms, or user selected choice
SmsManager.getSmsManagerForSubscriptionId(smsToSendFrom)
                            .sendTextMessage(phoneNumber, null, msg, sentPI, deliveredPI); //use your phone number, message and pending intents