How to create Restful service and deploy it OSGi container?

Question

My goal is to create a Restful service Maven project with Eclipse. Then package it as a bundle and deploy it to Fuse ESB karaf OSGi container. So far what I know is how to use the JAX-RS API annotations, @Path @GET:

package com.restfultest;

import javax.ws.rs.GET;
import javax.ws.rs.Path;

@Path("/example")
public class ExampleService {

@GET
public String sayHello() {
    return "Hello Restful service";
 }
}

My question is that: 1. what maven archetype should I use? maven-archetype-webapp or quickstart?

2.How to implement Activator? Like this?

public class Activator implements BundleActivator {

private ServiceRegistration<?> registration;

public void start(BundleContext context) throws Exception {
    // TODO Auto-generated method stub
    ExampleService exampleService = new ExampleService();
    registration = context.registerService( ExampleService.class.getName(), exampleService, null );
}

public void stop(BundleContext context) throws Exception {
    // TODO Auto-generated method stub
    registration.unregister();
}

}

3. How to register and publish the service (like how to configure the Endpoint address and port)?

I am new to osgi. Does anyone can provide me some resources or a detailed tutorial?

Answer 1

1. You can use Maven bundle plugin
2. and 3. Apache CXF DOSGi helps you to publish OSGi services as WS/REST.

Answer 2

Here is my 5 cent:

1. What Maven archetype should you use?

• I used the OSGI HTTP Service (Quick Start), check this sample, I considered it was more natural.

2. How to implement Activator?

• Go ahead and use the Activator of the sample, it worked for me.
• If you use it, you also will need to implement the the Application and the Rest Service

3. How to register and publish the service?

• I recommend you to download the latest jersey-ALL-bundle and install it on your OSGI.

• And then, in my particular case, I used the Maven Bundle Plugin to handle the imports on Runtime and packing, so, my pom.xml looks something like this (Please notice the dependencies):

   ... <packaging>bundle</packaging> <build> <plugins> <!--+ + OSGi Bundle-Manifiest Generator. + --> <plugin> <groupId>org.apache.felix</groupId> <artifactId>maven-bundle-plugin</artifactId> <version>2.3.7</version> <extensions>true</extensions> <configuration> <instructions> <Import-Package>javax.servlet.*;version="[2.4,4.0)",*</Import-Package> <Bundle-Activator>com.sample.api.Activator</Bundle-Activator> <Implementation-Title>jersey-osgi-http-service-bundle</Implementation-Title> <Implementation-Version>${project.version}</Implementation-Version> </instructions> <unpackBundle>true</unpackBundle> </configuration> </plugin> </plugins> </build> <dependencies> <!--+======================+--> <!--+ REST Dependencies +--> <!--+======================+--> <dependency> <groupId>org.glassfish.jersey.containers</groupId> <artifactId>jersey-container-servlet-core</artifactId> <version>2.22.1</version> </dependency> <dependency> <groupId>org.apache.felix</groupId> <artifactId>org.apache.felix.http.bundle</artifactId> <version>2.2.0</version> </dependency> <!--+=========================================+--> <!--+ Apache Felix Framework (OSGi framework) +--> <!--+=========================================+--> <dependency> <groupId>org.apache.felix</groupId> <artifactId>org.apache.felix.framework</artifactId> <version>4.6.0</version> </dependency> </dependencies>

• In my specific case I have also the WebConsole installed , then my bundles look like this:

   0|Active | 0|System Bundle (4.6.0) 1|Active | 1|Apache Felix Bundle Repository (2.0.2) 2|Active | 1|Apache Felix Gogo Command (0.14.0) 3|Active | 1|Apache Felix Gogo Runtime (0.12.1) 4|Active | 1|Apache Felix Gogo Shell (0.10.0) 5|Active | 1|com.sample-api (1.3.0.SNAPSHOT) 6|Active | 1|jersey-all (2.22.1) 7|Active | 1|Apache Felix Log Service (1.0.0) 8|Active | 1|Apache Felix Configuration Admin Service (1.2.4) 9|Active | 1|Apache Felix Shell Service (1.4.2) 10|Active | 1|Apache Felix Http Bundle (2.0.4) 11|Active | 1|HTTP Service (1.0.0) 12|Active | 1|Apache Felix Web Management Console (3.1.2)

• For Rest it's important to have the bundles 6, 10 and 11.

• And the port is configurable in the "config.properties" of the OSGI (I used Felix) just by doing this:

   org.osgi.service.http.port=28370

• Then, to reach the service just use the following path:

   http://localhost:28370/jersey-http-service/status

Answer 3

1. You'll need to create an OSGI bundle. There are a few archetypes that create maven projects:

   • http://mojo.codehaus.org/mojo-archetypes/osgi-archetype/
   • http://www.sonatype.com/books/mcookbook/reference/sect-osgi-generate-project.html

2. Your activator looks correct.

3. This question I cannot answer, but it looks like this project does what you need: https://github.com/hstaudacher/osgi-jax-rs-connector

In general I recommend you get yourself the OSGI specification , it's a good read and explains a lot of things.