Send SMS until it is successful

Here is what I have done:

public class SMSSender extends IntentService {

public static final String INTENT_MESSAGE_SENT = "message.sent";
public static final String INTENT_MESSAGE_DELIVERED = "message.delivered";

public static final String EXTRA_MESSAGE = "extra.message";
public static final String EXTRA_RECEIVERS = "extra.receivers";

public SMSSender() {
    super("SMSSender");
}

private final String TAG = "SendSMS";


private static class IDGenerator {

    private static final AtomicInteger counter = new AtomicInteger();

    public static int nextValue() {
        return counter.getAndIncrement();
    }
}

private void sendSMS(String message, String[] receivers) {

    SmsManager sm = SmsManager.getDefault();

    ArrayList<String> parts = sm.divideMessage(message);

    PendingIntent sentPI = null;
    PendingIntent deliveredPI = null;

    Intent sentIntent = new Intent(INTENT_MESSAGE_SENT);

    int sentID = IDGenerator.nextValue();
    sentPI = PendingIntent.getBroadcast(SMSSender.this, sentID, sentIntent,
            PendingIntent.FLAG_CANCEL_CURRENT);

    Intent deliveryIntent = new Intent(INTENT_MESSAGE_DELIVERED);

    int deliveredID = IDGenerator.nextValue();
    deliveredPI = PendingIntent.getBroadcast(SMSSender.this, deliveredID,
            deliveryIntent, PendingIntent.FLAG_CANCEL_CURRENT);

    Log.i(TAG, "sending SMS: parts: " + parts.size() + " message: "
            + message);

    if (parts.size() > 1) {
        ArrayList<PendingIntent> sentIntents = null;
        ArrayList<PendingIntent> deliveredIntents = null;

        sentIntents = new ArrayList<PendingIntent>();
        deliveredIntents = new ArrayList<PendingIntent>();

        for (int i = 0; i < parts.size(); i++) {
            sentIntents.add(sentPI);
            deliveredIntents.add(deliveredPI);
        }

        for (String receiver : receivers) {
            try {
                sm.sendMultipartTextMessage(receiver, null, parts,
                        sentIntents, deliveredIntents);
            } catch (IllegalArgumentException e) {
                Log.e(TAG, "illegal receiver: " + receiver);
            }

        }
    } else {
        for (String receiver : receivers) {
            try {
                sm.sendTextMessage(receiver, null, parts.get(0), sentPI,
                        deliveredPI);
            } catch (IllegalArgumentException e) {
                Log.e(TAG, "illegal receiver: " + receiver);
            }
        }
    }
}

@Override
protected void onHandleIntent(Intent intent) {
    String message = intent.getStringExtra(EXTRA_MESSAGE);
    String[] receivers = intent.getStringArrayExtra(EXTRA_RECEIVERS);

    sendSMS(message, receivers);

}

And to use it:

    private void startMessageServiceIntent(String message, String receiver) {
        Intent i = new Intent(context, SMSSender.class);
        i.putExtra(SMSSender.EXTRA_MESSAGE, message);
        i.putExtra(SMSSender.EXTRA_RECEIVERS, new String[] { receiver });
        startService(i)
    }

Notice it supports multiple receivers, which this method does not demonstrate/use.

Remember in your manifest:

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

<service android:name="your.package.SMSSender" android:enabled="true" />

Optionally you can listen for when messages are sent and/or delivered:

@Override
protected void onCreate() {

    ...

    // ---when the SMS has been sent---
    private BroadcastReceiver messageSent; // <- stored as a field
    messageSent = new SentMessage(); 
    registerReceiver(messageSent, new IntentFilter(SMSSender.INTENT_MESSAGE_SENT));

    // ---when the SMS has been delivered---
    private BroadcastReceiver messageDelivered; // <- stored as a field
    messageDelivered = new MessageDelivered();
    registerReceiver(messageDelivered, new IntentFilter(
            SMSSender.INTENT_MESSAGE_DELIVERED));
}

@Override
protected void onDestroy() { // remember to unregister
    unregisterReceiver(messageSent);
    unregisterReceiver(messageDelivered );
}

I know this does not demonstrate answers to all your questions but I hope that it is sufficient.

Edit: Added my implementations of messageSent and messageDelivered

These are specific to my implementation, so includes some code that you cannot use, it is simply for demonstration.

Message sent:

public class SentMessage extends BroadcastReceiver {

private final String TAG = "SentMessage";

@Override
public void onReceive(Context context, Intent intent) {
    long _id = intent.getLongExtra(EXTRA_ID, -1);
    long protocol_id = intent.getLongExtra(EXTRA_PROTOCOL, -1);
    Log.d(TAG, "SentMessage");
    switch (getResultCode()) {
    case Activity.RESULT_OK:
        Log.d(TAG, "RESULT_OK");
        if (MessageData.sentMessage(_id, protocol_id)) {
            try {
                Database.messageSent(_id);
            } catch (DatabaseRowNotFoundException e) {
                Log.e(TAG, e.toString(), e);
            }
        }
        break;
    case SmsManager.RESULT_ERROR_GENERIC_FAILURE:
        Log.d(TAG, "RESULT_ERROR_GENERIC_FAILURE");
        MessageData.postponeMessage(_id);
        ApplicationData.hasSignal(false);
        break;
    case SmsManager.RESULT_ERROR_NO_SERVICE:
        Log.d(TAG, "RESULT_ERROR_NO_SERVICE");
        MessageData.postponeMessage(_id);
        ApplicationData.hasSignal(false);
        break;
    case SmsManager.RESULT_ERROR_NULL_PDU:
        Log.d(TAG, "RESULT_ERROR_NULL_PDU");
        break;
    case SmsManager.RESULT_ERROR_RADIO_OFF:
        Log.d(TAG, "RESULT_ERROR_RADIO_OFF");
        MessageData.postponeMessage(_id);
        ApplicationData.hasSignal(false);
        break;
    }

}

Message delivered:

public class DeliveredMessage extends BroadcastReceiver {

private final String TAG = "DeliveredMessage ";


@Override
public void onReceive(Context context, Intent intent) {

    long _id = intent.getLongExtra(EXTRA_ID, -1);
    long protocol_id = intent.getLongExtra(EXTRA_PROTOCOL, -1);
    switch (getResultCode()) {
    case Activity.RESULT_OK:
        if (_id != -1 && MessageData.deliveredMessage(_id, protocol_id)) {
            try {
                Database.messageDelivered(_id);
                Cursor messageCursor = Database.getCursorByID(MessageOutboxContentProvider.CONTENT_URI, MessageOutboxContentProvider._ID, _id);
                messageCursor.close();
            } catch (DatabaseRowNotFoundException e) {
                Log.e(TAG, e.toString(), e);
            }
        }
        break;
    case Activity.RESULT_CANCELED:
        break;
    }
}

}

I was in the need for reliable sending too, so kept references to all pending messages in a database, which I would frequently scan for postponed messages. A message would get postponed if there is no radio, or the sending simply fails for whatever reason.

I also used GCM together with SMS to get the message delivered as fast as possible, sending messages using both channels at the same time.

Edit2: Oh well, might as well address the questions, we are almost there anyway:

Question 1: Since using IntentService the sending is done in the background.

You only want the sending to happen once after a delay so you should do this instead:

    new Handler().postDelayed(new Runnable() {

        @Override
        public void run() {
            // send sms
        }
    }, delay);

Question 2: Easy, when your sent message broadcast detects an error do the above method. You could add an extra information, besides receiver and message, counting the number of retries up until now so you have a chance of stopping the send/retry loop.

Question 3: The sending stops by itself, as it is an Intent Service. As for the other service the most simple approach, I think, would be to send a common broadcast, which is picked up by your main activity. This way you can get a hold of the service the right place and stop it.