[ecf-dev] My first steap with ECF with Restlet

[Angelo zerr <angelo.zerr@xxxxxxxxx>]

Hi Scott, 

At first time for your information I have written several articles about remoting with CXF DOSGi at http://angelozerr.wordpress.com/about/eclipse_spring/eclipse_spring_dosgi/


I know it's not ECF topic but if you can it should be cool if you can read to know what I need, on other words : just add some annotations in my interface services (in my case JAX-RS) and that's all!

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package fr.opensagres.services;

import java.util.Collection;

import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;


import javax.ws.rs.QueryParam;
import javax.ws.rs.core.MediaType;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;

import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;


import org.springframework.data.domain.jaxb.PageAdapter;
import org.springframework.data.domain.jaxb.PageableAdapter;

import fr.opensagres.domain.User;

@Path("/user")
public interface UserService {


    @POST
    @Path("/findAllPage")
    @Consumes({ MediaType.APPLICATION_JSON })
    @Produces({ MediaType.APPLICATION_JSON })
    @XmlJavaTypeAdapter(PageAdapter.class)
    Page<User> findAll(


            @XmlJavaTypeAdapter(PageableAdapter.class) Pageable pageable);

}
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My service has one parameter where Pageable is Spring Data structure which is an interface (and not a Pojo!). It returns Page structure which is too an interface. 


I have done that with sucess with CXF DOSGi. As you suggested me to use ECF, I have started to study ECF with Restlet.

I have cloned the whole projects https://github.com/ECF/RestletProvider and start to play with them. 


1) TargetPlatform with ECF, Restlet and Servlet API.

Thoses projects have several dependencies and to resolve this problem I have created a Target Platform P2 with ECF, Restlet and RAP (to have Jetty server+Servlet API). I think it should be cool if in your git ECF Restlet you provide this Target Paltform.


2) Restlet RSA Server.launch

I think it should be cool in your Git description to speak about URL to access to the service with Web Browser.

I have launch Restlet RSA Server.launch and after debugging the code I have noticed that I can access to my service with the URL http://localhost:8080/hello which displays: 


-------------------------------------------------------------------------------------------

Hello RESTful OSGi World

-------------

Why this URL? I don't know why?

IHelloResource uses restlet annotation lie this: 


-----------------------------------------------------
public interface IHelloResource {
    @Get("txt")
    public String sayHello();

    @Get("html")
    public String getDocument();


}-----------------------------------------

Where "hello" path is declared? 

After studying that, I notice that it is declared in the hellow.xml : 

-----------------------------------------

<property name="paths" type="String">
     /hello
   </property>
-----------------------------------------

I told that because I think it should be cool if you describe the URL in your Git description and explains why /hello is used?

3) Restlet Hello Consumer.launch

After that I launch the client side "Restlet Hello Consumer.launch" and there is none error and nothing is displayed on the console (my IHelloService is never found).

I don't understand how it can work? You have never declared a Rest Client like with the URL http://localhost:8080/hello ?

4) What I don't like with Restlet.

On client side, I cannot tell anytthing because I don't understand how it works.
On server side, you have the implementation of  the service like this: 

-----------------------------------------
public class HelloResource extends ServerResource implements IHelloResource {
    @Get("txt")
    public String sayHello() {
        return "Hello RESTful OSGi World";
    }
...
-----------------------------------------

4.1) ServerResource dependency : Your service must extends Restlet ServerResource class, so your implementation has dependencies to restlet. If you wish change remoting mode (eg : ECF REST -> DOSGi CXF), you need to keep Restlet dependencies and I find it's shame.
4.2) HelloResourceProvider must be defined :
-----------------------------------------

public class HelloResourceProvider extends ResourceProvider {
    @Override
    protected Finder createFinder(Context context) {
        return new Finder(context, HelloResource.class);
    }
}
-----------------------------------------

I think it's complex task to manage remoting. With DOSGi CXF you need just uses JAX-RS annotations. With ECF Restlet you need uses Restlet annotations+extends ServerResource+create ResourceProvider.

None offense with my comment. I tell you just why (for the moment), I prefer  CXF DOSGi than ECF Restlet.

Regards Angelo