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Design a Plugin based system

Cainiao Zou
Ranch Hand

Joined: Mar 03, 2009
Posts: 36
Hi everybody.

I'm trying to make a plugin-based application which means, besides the basic framework, other functionalities should be added with a plugin style.

The majar problem of such system, i think, is how to load new plugins at the runtime. I don't want to recomplie the whole project when a new plugin installed. Just like Eclipse, after new installation of plugin, the user only need to restart it.
So my first idea about that is using java reflection to load the class at the runtime. there might be some plugin configuration files, the system reads them and load the plugin classes with reflection. Maybe i can use the spring framework as well, because its Inversion of Control is just match my request.

Another idea i'm investigating is using the ejb container. when the plugins are ejbs, i can just pack them into jar and deploy them in an ejb container, then i can use jndi to access them. but it only works when the plugin are ejbs.

anyway, i'm a rookie in system design. so i post this topic and want to hear of your opinions.
btw. is there any good book about system design you want to recommand?

thanks alot in advance!
Ulf Dittmer

Joined: Mar 22, 2005
Posts: 42965
The low-end, not production-ready, but possibly sufficient, approach:

The high-end approach: OSGi, possibly as implemented using something like Apache Karaf.
I agree. Here's the link:
subject: Design a Plugin based system
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