Re: [platform-core-dev] Use of Eclipse plugin framework in pure Java app

[Martin Lippert <lippert@xxxxxxx>]

Hi!

> I would like to use the Eclipse plugin framework to deploy pure Java
> applications. I work on a set of closely related pure Java applications,
> both non-GUI (standalone and MBeans) and Swing-based GUI (with WebStart and
> InstallAnywhere installers), that I would like to build as a collection of
> components. Since I really like the Eclipse plugin architecture, I would
> like to use it as my component architecture. However, I do not want to use
> any non-Java Eclipse code, SWT, or the main eclipse.exe.
>
> Has anybody done this? 
Sure. We are using the Eclipse plugin infrastructure to develop some of 
our normal applications and it works fine. For example a banking 
workplace where third-party-companies are able to add new products and 
product selling tools to it using plugins (just to mention one).

> Are there any dependencies in the base plugin framework on native platform
> code, e.g., org.eclipse.core.resources.*, that would make it impossible to
> reuse the implementation of the framework in a pure Java context?
From my point of view there are no additional dependencies. The core 
packages are pure Java, I think. But there are a few things you might 
should  keep in mind because they can cause problems when building a 
system out of plugins:

- Libraries from other vendors might use a special class loading 
implementation for their customization. I know one that uses the system 
class path to load classes via a special class loader. This kind of ugly 
implementation does not work in the context of plugins.

- The serialization mechanism of Java causes some problems. Just think 
of a situation where you what to serialize some objects which classes 
are defined in different plugins. Okay. But the de-serialization fails 
in the default case. You have to implement a special object input/output 
stream to store additional information into the stream from which plugin 
a class used inside the stream is. Or does somebody knows a more elegant 
solution? I would be happy to hear.


> In order to ship an application using WebStart, all content must be in jars.
> I understand that putting plugin.properties and plugin.xml into a jar and
> breaking the directory structure, e.g., a single directory containing all
> jars requires some change to the plugin framework. Are there any fundamental
> issues with the current implementation that would make these changes very
> difficult?
We used WebStart to deploy an Eclipse-plugin-based application. 
Therefore we build a special startup class that configures the plugin 
directory with the downloaded jars and starts the Eclipse launcher. 
Works fine!

Best regards,
Martin