OSGi Plugin

Overview

The Struts 2 OSGi plugin leverages OSGi to allow Struts 2 applications to be divided into multiple jars (bundles) and managed at runtime. It allows you to separate your application into jars (called bundles), each containing a struts.xml file, Action classes, and Velocity (for now) files.

Features

• Application packages can be divided into bundles
• Supports Velocity templates

Missing Features

• No GUI for bundle administration
• Probably can't access application classes from bundles, including Spring classes
• No support for any results other than Velocity

Usage

To convert your jar that contains Actions, Velocity files, and a struts.xml file into a bundle, add a few lines in the jar's manifest.mf:

Bundle-Activator: org.apache.struts2.osgi.StrutsActivator
Export-Package: com.mycompany.myapp.actions
Bundle-Version: 1.0.0
Bundle-SymbolicName: foo.actions

Now the jar is ready to be deployed. Drop the jar into the /WEB-INF/classes/bundles directory and it will automatically be installed when the application starts up.

Example

Here is how an example architecture would look:

Settings

The following settings can be customized. See the developer guide.

Installation

Follow these steps to use this plugin:

• Copying the plugin jar into your application's /WEB-INF/lib directory.
• Modify your web.xml to add the osgi configuration provider to your Struts 2 filter:

  <filter>
      <filter-name>struts2</filter-name>
      <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
      <init-param>
          <param-name>configProviders</param-name>
          <param-value>org.apache.struts2.osgi.OsgiConfigurationProvider</param-value>
      </init-param>
  </filter>
  

Resources

• OSGi
• Apache Felix

Version History