Question

I’m using the Equinox OSGi implementation. When I retrieve a bundle and ask it for its location (getLocation() method) the returned String is prefixed with “initial@reference”. The OSGi 4.3 specification does not mention this prefix. Is there another document where this prefix and other possible prefixes are specified?

Answer 1

These are Equinox specific URL prefixes (although the reference: prefix is also supported by other OSGi Frameworks). They are not a part of OSGi Spec. From Eclipse Runtime Options:

osgi.bundles
The comma-separated list of bundles which are automatically installed and optionally started once the system is up and running. Each entry is of the form:

    <URL | simple bundle location>[@ [<start-level>] [":start"]]

The start-level indicates the OSGi start level at which the bundle should run. If the start-level (>0 integer) is omitted then the framework will use the default start level for the bundle. If the “start” tag is added then the bundle will be marked as started after being installed. Simple bundle locations are interepreted as relative to the framework’s parent directory. If the location is not a fully qualified path or URL then a search is done to find the highest version available. Note that the reference: protocol can only be used to refer to content specified by a file: URL (e.g. reference:file:/path/to/mybundle_1.0.0.jar). If the bundle is a directory bundle then using a file: URL without the use of reference: is not supported (e.g. file:/path/to/myDirectoryBundle_1.0.0/ must use reference:file:/path/to/myDirectoryBundle_1.0.0/)

here is a thread with description of “initial” and “reference” prefixes.