import com.elarian.*;
import com.elarian.model.*;

// ...

String appId = "test_app";
String orgId = "test_org";
String apiKey = "test_api_key";

Elarian app = new Elarian(apiKey, orgId, appId);

app.connect(new ConnectionListener() {
    @Override
    public void onPending() {
        log.info("Pending...");
    }

    @Override
    public void onConnecting() {
        log.info("Connecting...");
    }

    @Override
    public void onClosed() {
        log.info("Connection Closed");
    }

    @Override
    public void onError(Throwable throwable) {
        log.error("Failed to connect: " + throwable.getMessage());
    }

    @Override
    public void onConnected() {
        log.info("Connected!");
        Tag tag = new Tag("some-key", "some-value");
        MessagingChannel channel = new MessagingChannel("2020", MessagingChannel.Channel.SMS);
        Message message = new Message(new MessageBody("This is a test"));
        app.sendMessageByTag(tag, channel, message)
                .subscribe(
                        res -> log.info(res.description),
                        err -> err.printStackTrace()
                );
    }
});
try {
    Thread.currentThread().join();
} catch (InterruptedException e) {
    e.printStackTrace();
}