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hstaudacher / osgi-jax-rs-connector

An OSGi - JAX-RS 2.0 Connector, software repository available on the link below
http://hstaudacher.github.io/osgi-jax-rs-connector
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OSGi - JAX-RS Connector 5.3.1 ***No longer maintained***

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JAX-RS (JSR 311) is the community-driven standard for building RESTful web services with Java. The reference implementation for JAX-RS is Jersey and ships as OSGi bundles. This project connects Jersey and OSGi at the service level. This means that OSGi services can be published as RESTful web services by simply registering them as OSGi services. A neat side feature is that REST services can also be consumed as OSGi services ;).

To see how to get started with JAX-RS 2.0 and Jersey please read the Jersey getting started guide. mox

Features

The OSGi-JAX-RS Connector provides two main bundles. A publisher and a consumer. Both can be used completely separately or together, it's up to you. Additional the connector provides custom @Provider and Feature implementations that can be used optionally.

Publisher

The publisher is located in the bundle com.eclipsesource.jaxrs.publisher. All it does is tracking OSGi services. When it spots a service that is annotated with the JAX-RS annotations @Path/@Provider or it extends Feature the work begins. The publisher hooks these services into Jersey and the OSGi HTTPService. Basically this means it publishes them as RESTful web services. It's just that simple!

By default the publisher registers the services using the context path /services. This means an OSGi service that is annotated with @Path( "/foo" ) will be available using the path /services/foo. This context path is configurable using the OSGi configuration admin. You can configure the service using the service.pid com.eclipsesource.jaxrs.connector with the following properties:

Besides the config admin you can configure the JAX-RS Application with properties too. Simply register a service implementing the ApplicationConfiguration interface. It will be called before the Application got published.

As said earlier, the publisher uses the OSGi HTTPService to publish the services. As a result all configuration topics regarding ports, protocol and so on are up to the HTTPService implementation of your choice.

If it's your wish to publish services on different ports, just register them and add the service property http.port with the port of your choice. Of course it's necessary that an HTTPService is up and running on such a port.

Consumer

The consumer is located in the bundle com.eclipsesource.jaxrs.consumer. The idea of the consumer is to reuse your @Path and @Provider interfaces for calling a service. From a technical point of view it takes your interfaces together with a base url and creates Java Proxies. These proxies will make an HTTP call when a method will be invoked on it. The proxy knows which http method, parameters and so on it should use because you have it defined with the JAX-RS annotations. The consumer uses the JAX-RS 2.0 client API to send requests. So, there will be no additional dependencies.

A nice side effect of the consumer is, that it does not need OSGi. It's just a jar that can be used to create the mentioned proxies. See the ConsumerFactory for more information.

When using it together with OSGi it provides a helper to create your proxies and automatically register them as OSGi services. But it's up to you if you want to take care regarding the publishing by your own. See the ConsumerPublisher for more information.

A detailed explanation of the concepts of the consumer together with some examples can be found on our blog: Consuming REST services in Java the cool way, Consuming REST services in OSGi the cool way.

Providers

The custom @Provider and Feature implementations are located in their own features. The following features are currently included.

Installation

To ease the installation we provide a p2 repository and we publish the connector to maven central.

p2

Install from this software repository into your target: http://hstaudacher.github.io/osgi-jax-rs-connector

Please note: If dependencies can't be satisfied please disable "include required software" within the target editor.

Maven

All artifacts of this projects are available in Maven Central with the group id com.eclipsesource.jaxrs.

Usage

A detailed step-by-step can be found here.

Basically all you need to to is add the publisher and/or the consumer to your OSGi container and start them. For people new to OSGi the steps to get started with the connector and Eclipse are described below.

  1. Add the com.eclipsesource.jaxrs.connector.feature (OSGi JAX-RS Connector) to your target using the url mentioned in the Installation/p2 section.
  2. Add the com.eclipsesource.jaxrs.publisher and its dependencies bundles to your OSGi instance.
  3. Convert some OSGi services to resources like in this tutorial
  4. Point your client to the specified url. Don't forget that the default root path is /services. So registering a service with the path /example would lead to /services/example.

The steps how the consumer will be handled are dscribed in this post.

Examples

Examples for the publisher and consumer can be found within the examples folder.

When using the example's Eclipse launch configuration please ensure that you have selected the connector bundles from your target.

Publisher Examples

Some examples exist for the publisher. They are located in the bundles com.eclipsesource.jaxrs.connector.example and com.eclipsesource.jaxrs.connector.example.ds. As the names say one uses Declarative services and the other don't. In both exampels a simple POJO is annotated with @Path and will be registered as an OSGIi service. Both bundles contain an Eclipse Launch Configuration to start them (please don't forget to add the publisher bundle to the launch config). After starting the launch configs the service will be available at http://localhost:9090/services/osgi-jax-rs.

As a bonus the com.eclipsesource.jaxrs.connector.example.ds contains an example how to use the @Provider together with the publisher.

Besides these basic example two example exist that are shwoing how the security integration and Jersey's SSE integration works.

Consumer Examples

The example for the consumer is splitted into two bundles called com.eclipsesource.jaxrs.consumer.example and com.eclipsesource.jaxrs.consumer.example.caller. The example bundle contains the data model and the resource interface while the caller just calls the service. The example fetches data from github and is pretty simple.

Apache Karaf Integration

If you want to deploy the connector into Apache Karaf take a look at the karaf-integration example. To get started read the step-by-step guide in the README.

Starter Kit

If you are working with Bndtools, a Starter Kit is available to help you get going. You will most likely want either the rest or mongo-rest branch.

Requirements

Jersey version

With Jersey 2.0 the library was splitted into several modules with a whole bunch of dependencies. To ease the OSGi application development Jersey was rebundled in this project and ships as a single bundle called com.eclipsesource.jaxrs.jersey.all. Currently it includes Jersey 2.22.2 and it's dependencies. Also the Eclipse Source Bundle will be shipped to make the Jersey API more discoverable when using Eclipse. Anyway, it's up to you to use this 'all' bundle or to fetch the single Jersey bundles yourself. The connector just imports packages.

Changelog

Checkout the github releases.

License

The code is published under the terms of the Eclipse Public License, version 1.0.

Included binaries from Jersey (rebundled), version 2.22.2, which are published under two licenses, the CDDL 1.1 and GPL 2 with CPE.

Included binaries from Swagger (rebundled), version 1.5.7, which are published under Apache License 2.0.