Working with the Plugins1 and Plugins2 versions

Let us also quickly see how to deal with the Plugins1 and Plugins2 versions.

Before we go on to the details, it is essential to understand the importance of both these versions. Pre 4.x, JIRA used to support only the Plugins1 version. So why do we need the Plugins2 version?

The key motive behind version2 plugins is to keep the plugins as a bundle isolated from the other plugins and the JIRA core classes. It makes use of the OSGi platform (http://www.osgi.org/) to achieve this. While it keeps the plugins isolated, it also gives you a way to define dependencies between plugins, leaving it to the plugin developer's convenience. It even lets you import or export selected packages within the plugin giving increased flexibility.

The fact that the version2 plugins are deployed as OSGi bundles also means that the plugins are dynamic in nature. They may be installed, started, updated, stopped, and uninstalled at any time during the running of the framework...