Extending Java Web Applications with plugins

Question

I have this web application that has grown to an unmanageable mess.

I want to split it into a common \"framework\" part (that still includes web stuff like pages and im

Answer 1

Depending on the complexity of the plugin functionality I would also be considering a web service, for instance implemented with Axis.

Your main appplication is then configured with the URL to the web application (plugin) which provides the service.

The advantage,as I see it, is twofold:

• You get a nice, clean, debuggable API between the two wars, namely the Soap/XML messages
• You are able to upgrade a single plugin without having to regression-test your entire application

The disadvatages are that you have to set up some Axis projects, and that you have to have some sort of plugin configuration. Furthermore you might need to limit access to your services web applications, so a bit of configuration might be required.

If the plugins work on the same database be sure to either limit cache time or to configure a war-spanning caching layer.