The config servlet init-param already specifies a URI in string form.  The sample app happens to use a relative URI, which is assumed to be relative to the location of plugin.xml, but it can also specify a fully qualified URI (e.g. file:/c:/foo/jaggr-config.js).  I'd like to see this method replaced with a getAppContextURI() method which will return a URI pointing to the context path for the application, which for the OSGi implementation will point to the directory containing the application's plugin.xml.  The aggregator can then use URI.resolve() to get the URI for the aggregator config when the config URI is a relative URI