Comments on: My thoughts about OSGi on JavaWorld

By: george

george — Sat, 13 Mar 2010 02:41:00 +0000

haha ^^ nice, is there a section to follow the RSS feed

By: You dreamt of it? SpringSource did it!

You dreamt of it? SpringSource did it! — Sat, 13 Mar 2010 12:24:00 +0000

[...] their acquisition of Covalent, the company behind Tomcat, I knew they were up to something. I even talked about it with Andrew Glover for JavaWorld. And now it’s real: SpringSource has just announced [...]

By: Sébastien

Sébastien — Sat, 13 Mar 2010 10:34:00 +0000

You’re not forced to write load and unload hooks. The only thing you need to do to bundle-ify a JAR is to add more information to META-INF/MANIFEST.MF. Now is this small overhead worth the development of a whole new standard that does much less than an existing and mature one and even competes with it? I don’t think so.

By: Ron

Ron — Sat, 13 Mar 2010 00:31:00 +0000

The point is to be able to specify module dependencies and compatibility information. This is important even for applications that don’t change modules at runtime – it allows easier upgrades and module sharing. Now JSR 277 gives you this without writing your code in the form of dynamically loadable modules. It simply replaces the system class loader with a more sophisticated one, and replaces the jar with a module archive that allows more flexibility, control and tidiness. From what I understand, to write an OSGi application, I need to write my code as OSGi modules, and provide load and unload hooks, similarly to Netbeans modules.

By: Sébastien

Sébastien — Sat, 13 Mar 2010 11:43:00 +0000

I don’t see the point in replacing the JAR system if it’s not to add dynamic features to it. And judging by the adoption of OSGI, this is really a major requirement from the community. Why won’t the OSGi people leave the spec team alone? I’m not part of OSGi myself, and the JCP is supposed to be the mechanism by which Sun listens to the community to enhance the Java platform, not a set of deaf comittees who do their thing on their own.
Now OSGi (JSR 291) already deals with the issues you mention, plus it adds dynamism with no major cost, so why reinvent the wheel?

By: Ron

Ron — Sat, 13 Mar 2010 09:57:00 +0000

There is something I don’t understand, and perhaps you can enlighten me. JSR 277 is supposed to replace (among other things) the jar system. I.e. it is supposed to address the modular composition of “static” applications, meaning applications that DON’T change their modules at runtime. Most Java applications are static. True, it also addresses dynamic applications as OSGi does, but this is not necessarily JSR 277’s main target problem. Now why is it that the OSGi people got all over this JSR? I want to write simple, static applications without jar/classpath hell, and JSR 277 mainly addresses THAT issue. Now, why won’t the OSGi people leave the spec team alone to do their work?

By: Sébastien

Sébastien — Sat, 13 Mar 2010 01:40:00 +0000

Great spirits think alike, Velo. I’m currently playing with Solstice (http://www.arum.co.uk/solstice.php) and even though it’s still a very early draft, I’m gathering bits and pieces to integrate it with Spring Dynamic Modules and Maven. And hopefully I’ll have a tutorial ready soon… Now could someone add a few hours to each day?

By: VELO

VELO — Sat, 13 Mar 2010 22:50:00 +0000

\o/

I read your interview and say “sh**, I’ve been working for two years on something else to read today there is something better on Earth, which solves some problems that we have right now.”

After reading it, I will start reading more about OSGi, and will look for another app server

So, can I add a question to this interview? How about flex? How OSGi on server side can helps flex Appliactions?

VELO