Equinox P2 Supply Framework

Although the EQUINOX/P2 supply framework replaces the update Manager in the Eclipse IDE version prior to Galileo, this transition is not easy for plug-ins and the builders of the update site, as these tools (such as the editor for the installable Unit [IU] file) GUI tools and Ant tasks and command line tools are far less mature than other Eclipse tools. However, the P2 framework does give end users a lot of benefit. This article highlights how to use the GUI tools-p2installer and p2agent-to install Eclipse and build eclipse profiles.

Abbreviations used in common use

GUI: Graphics user interface (graphical user interface)

IDE: Integrated development environment (integrated development environment)

Jar:java Archive file (Java archive)

SDK: Software Development Kit (Software Development Kit)

The EQUINOX/P2 framework also introduces changes to how Eclipse components are packaged. To describe changes in metadata information and how that information is used, the following new terms are introduced:

Installable Units (installable Unit)-provides metadata for information such as name, version, and requirements. The information contained in IU allows the EQUINOX/P2 framework to install these products. IU Editor is currently available only through Subversion (SVN) within a developer project.

Profile-within the EQUINOX/P2 framework, features and Plug-ins are the same as in previous versions of Eclipse. However, they can now be installed as profiles, which is the new concept introduced by EQUINOX/P2. By creating a different eclipse profile, you can obtain a distinct eclipse instance or configuration in a different way (but using a generic plug-in file).

Use the EQUINOX/P2 supply within the Eclipse Workbench

The EQUINOX/P2 provisioning Framework is an alternative to the previous update Manager, so if you want to update Eclipse within this IDE, you will need to use the standard help > Check for Updates in Galileo. To install the new software, click Help > Install new Software.

A bright spot in the EQUINOX/P2 supply framework is the concept of drop-in, drop-in refers to plug-ins that are put into a directory location in the form of an archive file (JAR) format or a standard directory structure. When Eclipse starts, it scans the Dropins folder for new Plug-ins and installs the Plug-ins. It is important to note that the EQUINOX/P2 developer uses the assumption that it will function as long as the plug-in is properly installed. So, as long as the plug-in is in the Dropins folder and its dependencies are resolved, it can be installed at Eclipse startup.

The design of the Dropins folder infrastructure makes it easier to remove plug-ins that are installed in this manner. The Dropins folder also supports the nested structure of the directory, which makes these put plug-ins very easy to organize. Listing 1 shows the contents of the Dropins folder the first time Eclipse was installed.

Listing 1. Contents of the Dropins folder

dropins/

0　directories,　0　files

Listing 2 shows how the Subclipse v1.6.x (from the archive site file) and the Regex Util plug-in are installed in this directory. After these files are placed in the Dropins folder, Eclipse installs them the next time it starts. I can't find them in Help > About installation information, which means you can only delete them from the Dropins folder.