import org.jboss.errai.bus.client.api.messaging.MessageCallback; //导入依赖的package包/类
private void sendMessage() {
    final String messageText = messageTextBox.getText();
    if ("".equals(messageText)) {
        setStatus("message is mandatory");
        messageTextBox.setFocus(true);
        return;
    }
    setStatus("sending message from Errai Bus Client ...");

    MessageBuilder.createMessage()
            .toSubject("HelloWorldService")
            .withValue(messageText)
            .done()
            .repliesTo(new MessageCallback() {
                public void callback(Message message) {
                    setStatus("Response from server: " + message.get(String.class, MessageParts.Value));
                }
            })
            .sendNowWith(messageBus);
}
 

import org.jboss.errai.bus.client.api.messaging.MessageCallback; //导入依赖的package包/类
/**
 * Called when the service is constructed.
 */
@PostConstruct
private void onPostConstruct() {
    bus.subscribe("NotificationService", new MessageCallback() { //$NON-NLS-1$
        @Override
        public void callback(Message message) {
            NotificationBean notification = message.getValue(NotificationBean.class);
            doNotify(notification);
        }
    });
}
 

import org.jboss.errai.bus.client.api.messaging.MessageCallback; //导入依赖的package包/类
/**
 * Called whenver the page is shown.
 */
@PageShown
public void onPageShown() {
    GWT.log("Subscribing to SitWatch topic."); //$NON-NLS-1$
    bus.subscribe("SitWatch", new MessageCallback() { //$NON-NLS-1$
        @Override
        public void callback(Message message) {
            SituationEventBean sitEvent = message.get(SituationEventBean.class, "situation"); //$NON-NLS-1$
            onNewSituation(sitEvent);
        }
    });
}
 

import org.jboss.errai.bus.client.api.messaging.MessageCallback; //导入依赖的package包/类
/**
 * Called when the service is constructed.
 */
@PostConstruct
private void onPostConstruct() {
    bus.subscribe("NotificationService", new MessageCallback() { //$NON-NLS-1$
                @Override
                public void callback(Message message) {
                    NotificationBean notification = message.getValue(NotificationBean.class);
                    doNotify(notification);
                }
            });
}