Best way to build a Plugin system with Java

Question!

How would you implement a Plugin-system for your Java application?

Is it possible to have an easy to use (for the developer) system which achieves the following:

  • Users put their plugins into a subdirectory of the app
  • The Plugin can provide a configuration screen
  • If you use a framework, is the license compatible with commercial developement?


Answers

Use PF4J. It has support for Web, Spring and Wicket. Easy to use and build the applications



I worked on OSGi for a week--an intense, nothing but OSGi week. At the end it was like a bad dream but I learned a lot.

I was able to get OSGi working (not easy, all examples are out of date, everything on the net is at least three years old if not five), but I had serious trouble getting it integrated into an existing project because of issues with the jar manifests.

In short, there are only a few obscure tools used for building manifests and they are not well documented (BND Tools is hardly obscure, but it is designed for a certain process in Eclipse). Also, most of the OSGi information available is not targeted towards application developers who have an existing desktop application.

This makes a lot of the context for the information foggy or inappropriate. Neil Bartlett's blog posts were the biggest help, but even those failed to get a working system (I grabbed some code from the Felix tutorial and pieced it together to get the embedded framework rolling). I found his book draft that he posted for free years ago, which is excellent, but the examples in Eclipse do not work because of changes in Eclipse OSGi support.

Every step is a major hurdle. I will try to post some more details here later.



By : jan


This video can help you solving your question :)
By: admin