Provide data for gwteventservice from different service

Question

I am trying to push data from my services to the browser with gwteventservice, but I am not able to do it from a different service then from MyServiceImpl.java. Here is the situtation: I have service DifferentService.java that reads data from client. Then I have class MyServiceImpl.java, which represents server side of MyService.java (clasic gwt project structure). Finally I have class CallEvent.java which uses addEvent method to send data to a listener (gwteventservice stuff). When I instantiate a CallEvent class within MyServiceImpl.java and call proper method (addEvent) a message is succesfully delivered to a listener. When I call same code from DifferentService.java class nothing happend (no message is delivered to a listener). I think this is a classic situation, when data need to be send from some data provider to a client utilizing gwteventservice. Could you please help me finding a problem? Which solution or approach do you use in such situations? Here are my code snippets used for data delivery.

MsgEvent.java (represents message carrying data - gwteventstuff)

public class MsgEvent implements Event {

    public static final Domain SERVER_MESSAGE_DOMAIN = DomainFactory.getDomain("my_domain");
    public String message;

    public MsgEvent(){}

    public MsgEvent(String message) {
            this.setMessage(message);
    }

    public String getMessage() {
            return message;
    }

    public void setMessage(String message) {
            this.message = message;
    }
}

CallEvent.java (gwteventstuff)

public class CallEvent extends RemoteEventServiceServlet{
    public void SendData(String data){
           //create the event
           Event theEvent = new MsgEvent("DagaMsg");
           //add the event, so clients can receive it
           addEvent(MsgEvent.SERVER_MESSAGE_DOMAIN, theEvent);
}
}

DifferentService.java

 public class DifferentService{
 ...
 //Reading string data from client
 CallEvent ce = new CallEvent();
 ce.SendData(stringData);        //this code delivers nothing to a listener
 ...
 }

MyServiceImpl.java (gwt stuff)

 public class MyServiceImpl extends RemoteEventServiceServlet implements MyService {
     public void sendMessage(String message) {
          CallEvent ce = new CallEvent();
          ce.SendData("Data");     //this code deliver message succesfully to a listener
     }
 }

web.xml (gwt and gwteventservice stuff)

<web-app>
    <!-- Default page to serve -->
    <welcome-file-list>
         <welcome-file>My.html</welcome-file>
    </welcome-file-list>
    <servlet>
        <servlet-name>MyService</servlet-name>
        <servlet-class>cz.pohanka.my.server.MyServiceImpl</servlet-class>
    </servlet>
    <servlet-mapping>
         <servlet-name>MyService</servlet-name>
         <url-pattern>/cz.pohanka.my.My/MyService</url-pattern>
    </servlet-mapping>
    <servlet> 
         <servlet-name>EventService</servlet-name> 
         <servlet-class>de.novanic.eventservice.service.EventServiceImpl</servlet-class> 
    </servlet>
    <servlet-mapping>   
         <servlet-name>EventService</servlet-name> 
         <url-pattern>/cz.pohanka.my.My/gwteventservice</url-pattern> 
    </servlet-mapping>
 </web-app>

I hope I have included everything important. I think that problem could be in web.xml. What do you think. Thank you.

Pavel

score 0 · Answer 1 · answered Dec 05 '12 at 12:52

I know the question was asked several months ago, but maybe it can help someone...

In your DifferentService, you can't create a servlet with new CallEvent() to send your event...

Instead, use something like:

EventExecutorServiceFactory pushServiceFactory = EventExecutorServiceFactory.getInstance();
EventExecutorService pushService = pushServiceFactory.getEventExecutorService( /* param */);
pushService.addEvent(...);

Replace param either by the HttpServletRequest or by a client id.

Provide data for gwteventservice from different service

1 Answers1