Example of Vaadin 7.1 server push with rxjava

Service.java

package com.github.oxlade39.vaadin;

import org.joda.time.DateTime;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import rx.Observable;
import rx.subjects.Subject;

import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

/**
 * @author dan
 */
public class Service {
    private static final Logger LOGGER = LoggerFactory.getLogger(Service.class);
    private static final int DELAY = 100;
    private final ScheduledExecutorService executorService;

    private final Subject<DateTime> dateTimeSubject = Subject.create();

    public Service(ScheduledExecutorService executorService) {
        this.executorService = executorService;

        executorService.scheduleWithFixedDelay(new Runnable() {
            @Override
            public void run() {
                DateTime dateTime = new DateTime();
                LOGGER.debug("publishing {}", dateTime);
                dateTimeSubject.onNext(dateTime);
            }
        }, DELAY, DELAY, TimeUnit.MILLISECONDS);
    }

    public Observable<DateTime> time() {
        return dateTimeSubject;
    }



}

View.java

package com.github.oxlade39.vaadin;

import com.vaadin.annotations.Title;
import com.vaadin.data.util.IndexedContainer;
import com.vaadin.server.VaadinRequest;
import com.vaadin.ui.Button;
import com.vaadin.ui.Table;
import com.vaadin.ui.UI;
import com.vaadin.ui.VerticalLayout;
import org.joda.time.DateTime;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import rx.Observable;
import rx.Subscription;
import rx.util.functions.Action1;

import static com.github.oxlade39.rx.Actions.runActionSafely;
import static com.github.oxlade39.rx.ToStringFunction.toStringF;

/**
 * @author dan
 */
@Title("Welcome")
public class View extends UI {
    private static Logger LOGGER = LoggerFactory.getLogger(View.class);

    private final VerticalLayout verticalLayout = new VerticalLayout();
    private Table table = new Table("My Table");
    private Button toggle = new Button("Start");
    private IndexedContainer dataSource = new IndexedContainer();

    @Override
    protected void init(VaadinRequest request) {

        setContent(verticalLayout);

        verticalLayout.addComponent(table);
        verticalLayout.addComponent(toggle);

        dataSource.addContainerProperty("name", String.class, "");
        table.setContainerDataSource(dataSource);

        final Service service = ((CustomVaadinServletService) request.getService()).getService();

        toggle.addClickListener(new SubscriptionClickListener(service, dataSource));
    }


    private class SubscriptionClickListener implements Button.ClickListener {
        private final Service service;
        private final IndexedContainer dataSource;
        private Subscription subscription;

        public SubscriptionClickListener(Service service, IndexedContainer dataSource) {
            this.service = service;
            this.dataSource = dataSource;
        }

        @Override
        public void buttonClick(Button.ClickEvent clickEvent) {
            LOGGER.debug("buttonClick {}", clickEvent);
            String caption = clickEvent.getButton().getCaption();
            if ("Start".equals(caption)) {
                subscribe(clickEvent);
            } else {
                cancelSubscription(clickEvent);
            }
        }

        private void subscribe(Button.ClickEvent clickEvent) {
            LOGGER.debug("Starting subscription");
            Observable<DateTime> time = service.time();
            subscription = time.map(toStringF()).subscribe(runActionSafely(View.this, new Action1<String>() {
                @Override
                public void call(String dateTime) {
                    dataSource.removeAllItems();
                    Object id = dataSource.addItem();
                    dataSource.getItem(id).getItemProperty("name").setValue(dateTime);
                }
            }));
            clickEvent.getButton().setCaption("Stop");
        }

        private void cancelSubscription(Button.ClickEvent clickEvent) {
            LOGGER.debug("Stopping subscription");
            subscription.unsubscribe();
            clickEvent.getButton().setCaption("Start");
        }
    }
}