Eclipse 3.4 插件 安装

Dropins

Provisioning operations should generally occur using the p2 UI, or by invoking p2 tools or APIs. However, there are situations where scripts need to install plugins and features via file system operations, and have the new content dynamically discovered by the system either at startup, or while running. To support this kind of low-level manipulation of the system, p2 supports the notion of watched directories. A watched directory is a place where a user or script can drop files and have them discovered by p2. Various policies can be applied to watched directories to configure when they are checked for new content, and whether to eagerly install discovered content.

The Eclipse platform ships with a default watched directory called dropins. The dropins folder is configured to be scanned during startup, and for changes to be immediately applied to the running system. Thus the dropins folder can be used much like the plugins directory was used in the past. A subtle twist on old behavior here is that plug-ins and features added to the dropins folder are properly installed into the system rather than being forced in. This means p2 has an opportunity to confirm that the new plug-in doesn't conflict with other installed plug-ins, and it can even go out and fetch any missing prerequisites of the newly dropped in plug-ins. This also means you can later use the GUI to install extra functionality that depends on the plug-ins in the dropins folder, since p2 knows about them and can reason about their dependencies. In other words, new plug-ins installed via the dropins folder behave exactly like plug-ins installed via the user interface. Note that updating plug-ins which are located under the dropins folder using the p2 UI will result in the updated plug-ins being saved under the main eclipse/plugins and eclipse/features folders and not under the dropins hierarchy as siblings to the older versions of the plug-ins, as might be expected.

Supported dropins formats

The dropins folder supports a variety of layouts, depending on the scale of your application and the desired degree of separation of its parts. The simplest layout is to just drop plug-ins in either jar or directory format directly into the dropins folder:

 eclipse/
   dropins/
     org.eclipse.core.tools_1.4.0.200710121455.jar
     org.eclipse.releng.tools_3.3.0.v20070412/
       plugin.xml
       tools.jar
       ... etc ...
   ...

You can also drop in the traditional Eclipse application or extension layout directly in the dropins folder:

 eclipse/
   dropins/
     eclipse/
       features/
       plugins/

If you have various different components being dropped in, and you want to keep them separate, you can add an additional layer of folders immediately below the dropins folder that contain traditional Eclipse extensions:

 eclipse/
   dropins/
     emf/
       eclipse/
         features/
         plugins/
     gef/
       eclipse/
         features/
         plugins/
     ... etc ...

Finally, you can add link files as in the traditional Eclipse links folder:

 eclipse/
   dropins/
     emf.link

原文地址: http://wiki.eclipse.org/Equinox_p2_Getting_Started