Managing the Eclipse Environment: the mystical art of Eclipse maintenance

Manage Plug-ins

What is a plugin? Why do I need to care about plug-ins?

Plug-ins (plug-in, also known as bundle) are functional blocks of Eclipse. In Eclipse, everything has its corresponding plugin, which includes:

Perspectives and views

Editor

Modeling Tools

Login and other core features

In fact, the entire Eclipse IDE is built as a collection of large plug-ins. Other eclipse-based products, such as IBM rational®software Architect, enhance basic eclipse by adding new plug-ins.

A set of related plug-in composition features. Attributes and their plug-ins exist in the Eclipse program directory (in this case, Eclipse is installed in the/opt/eclipse directory). The following is an example of a directory layout:

Listing 1. Eclipse attributes and Plug-in directory structure

/opt/eclipse/
　　features/
　　　org.eclipse.jdt_3.1.1/
　　　　　feature.xml
　　　　　 ...
　　plugins/
　　　org.eclipse.jdt.ui_3.1.1.jar
　　　...

Eclipse can have many of the same plug-ins, one for each different version. It knows how to fix plug-in dependencies and avoid versioning conflicts, so you never have to worry about installing two Subclipse plug-ins at the same time.

In the long run of Eclipse, you will always add new functionality by downloading Third-party plug-ins or by creating your own plug-ins. Managing these plug-ins across different versions of Eclipse can be a hassle. Because plug-ins exist in the Eclipse program directory, they are lost if you install a new version of Eclipse. This means that if you have more than one eclipse installation, you must save multiple copies of a large number of plug-ins, and even if you want to upgrade eclipse every time, you can only bother to reinstall it all.

If you store plug-ins in a separate location outside of the Eclipse program directory, you do not need to reinstall them when you upgrade to a new version of Eclipse, and you can share plug-ins across multiple versions of Eclipse.

Implementation control: Method 1--Manual File system extensions

There are three ways to control plug-in implementations. The first approach is to manually create a directory where plug-ins can be saved (called Product extensions), move the plug-ins to that directory, and then tell Eclipse to look for features and plug-ins here.

In our example, we will create a location named/opt/eclipse-plugins to store the plug-in. In order for Eclipse to store plug-ins here, you must first create the following directory structure and files:

Listing 2. Eclipse Product Extension directory structure

/opt/eclipse-plugins/
　　eclipse/
　　　.eclipseextension
　　　features/
　　　plugins/