groovy-osgi-console

This project aims to provide command line access to OSGi run time environment so that exploring services becomes easier.

Introduction

Any one who has worked with a OSGi container (such as http://www.eclipse.org/virgo) would attest to the fact that exploring services and their APIs is a non-trivial task. You might end up writing a test bundle that does nothing but call the APIs you want to play with. This is very tedious as any small change requires full compilation and deployment in the container. Alternatives exist but none of them are much better.

This process is especially annoying to some one who is accustomed to firing up a shell such as Jython or Groovy, start instantiating classes and calling Java APIs from the command prompt. It is the quickest way of playing around with Java APIs that obviates the need to write classes and compile them. How ever, this approach doesn't work with a OSGi contaner such as Virgo because all the java services are only available to the code running in the container. So I started looking for ways of running a server in the container that provides network connection to an outside shell such as Jython. With the power of Google, I soon found out the following excellent article:

http://groovy.codehaus.org/Embedding+a+Groovy+Console+in+a+Java+Server+Application

which in turn led to:

http://69.89.31.118/~iterativ/wordpress/2007/05/14/embedding-a-groovy-console-in-a-java-server-application

The above project aims to do something very similar but in a Spring MVC world. I took the code and modified it in order to get it working in OSGi. The code is tested with Virgo.

Building

You can simply start using the server found in the "dist" folder of the repository. How ever, if you need to make some changes in the server or perhaps want a different version of Groovy (the distributed server is built with Groovy 2.0.5), you do need to build it locally. The build requires "groovyc" to be available.

$ cd groovy-osgi-console
$ build.sh

This builds a bundle called "groovy-osgi-console-server.jar".

Deployment

Install "groovy-osgi-console-server.jar" in the OSGi container and start it. The bundle has no external dependencies (all its dependencies are packaged with in the jar file).

In case of Virgo, just copy it to the $VIRGODIR/pickup and Virgo would automatically load it.

Usage

Let us assume that we have a OSGi service available that implements the following interface:

public interface Service {
    public String echo(String message);
}

Here is one possible way of obtaining the service and calling its method.

$ telnet localhost 6789 (or)
$ nc localhost 6789

groovy:000> refs = context.getAllServiceReferences("com.example.Service", null)

groovy:000> service = context.getService(refs[0])

groovy:000> service.echo("Hello, World!\n")
Hello, World!

TODO

The project can use some love in the form of following enhancements, though it works perfectly good enough for me in its present incarnation.

Have a Makefile instead of shell script
Currently, all the dependencies are checked in to the repo. instead, one should be able to build the project with latest versions of those dependencies instead of being forced to use the checked in versions.

Contact

Please send email to draghuram at gmail dot com if you have any feedback and/or questions.

Acknowledgements

Huge thanks go to Bruce Fancher whose idea and code are shamelessly stolen. Similarly, Groovy folks deserve appreciation for a language whose excellent integration with Java made this project possible.

draghuram/groovy-osgi-console