Use Plugin Classpath with Openfire Plugin

July 31, 2008

When creating an Openfire plugin, some classes cannot be found by the
default classpath. This is a result of the way that Openfire loads plugins and their jars into
the classpath. For me, specifically, I got a ClassNotFoundException when trying to create an
IntialContext with WLIntialContextFactory, even though the weblogic.jar was in my plugin lib
folder. One solution is to move everything from the plugin/lib folder into openfire/lib. But
this is messy at best.

Luckily, I found a solution from someone trying
to use
GWT in an Openfire
Plugin.

First, set a PluginClassLoader on your Plugin class.
Here is my trimmed example:

…
private
PluginClassLoader pluginClassLoader = null;
…
public void
initializePlugin(PluginManager pManager, File pluginDirectory) {
pluginClassLoader
= pManager.getPluginClassloader(this);
}
…
public
PluginClassLoader getPluginClassLoader() {
return pluginClassLoader;
}


Then, in my class that attempts to load
a Context, before loading it I do this:

MyPlugin myPlugin =
(MyPlugin) XMPPServer.getInstance()

.getPluginManager().getPlugin(“myplugin”);
if (myPlugin != null &&
myPlugin.getPluginClassLoader() != null) {

Thread.currentThread().setContextClassLoader(

myPlugin.getPluginClassLoader().getClassLoader());
}