I am getting "Missing packages" exceptions when using 2.0M4 under KF OSGi.
I load:
org.restlet.jar, #22 then
org.json.jar, #23 then
org.restlet.ext.json.jar #24
with no error.
noting in the jar manifests
org.restlet.jar
exports org.restlet.resource, etc
it imports org.json
org.json.jar
exports nothing - it is a non-OSGi jar.
org.restlet.ext.json
Export-Package org.restlet.ext.json;uses:="org.restlet.resource, org.json"
Import-Package org.json org.restlet.resource & others
and the jar [LIST] includes
org/restlet/ext/json
JsonConverter.class
JsonRepresentation.class
I then start org.restlet.jar (Activator class
=org.restlet.engine.internal.Activator) #22
it resolves then returns from start.
I then start bundle #34 which uses Restlet. Its jar says
Import-Package org.osgi.framework;version="1.3.0",...,
org.restlet,...
org.restlet.resource, ...
org.restlet.ext.json,
org.json
During resolution, it is not able to find org.restlet.ext.json & org.json
and it throws exception:
ERROR 20090813 19:08:27 bid#34 - FrameworkEvent ERROR (
org.osgi.framework.BundleException:
'Unable to resolve bundle:
missing package(s) or can not resolve all of the them:
org.restlet.ext.json,
org.json).
It seems to me that no bundle is exporting org.json.
Can an OSGi expert help steer me through this. I am not an OSGi expert, but I
see things being done differently here from how similar things were done by KF
in porting GWT to OSGi and wonder if that relates to my Exceptions.
I see the Restlet code tends to use the "uses" qualification in Export-Package
clauses. My limited understanding of "uses" is that it is required to help
resolve when there are several versions of the same package in a framework and
provides a way to enforce that all classes needing to share one version and
class loader do so. My understanding is that it is not intended to help
reference a non-osgi jar.
To include a non-osgi jar, and looking at the KF GWT implementation, I see that
they have a bundle include the non-osgi library bundle as part of the using
OSGi bundle. In the case I am looking at, org.restlet.ext.json.jar would
include json.jar in org.restlet.ext.json.jar and then include a reference to it
with Bundle-Classpath.
This is described in OSGi R4.1 doc at 3.8.1 Bundle Class Path:
"Intra bundle class path dependencies are declared in the Bundle-Classpath
manifest header. This declaration allows a bundle to declare its embedded class
path using one or more JAR files or directories that are contained in the
bundle’s JAR file. The Bundle-Classpath manifest header is a list of
comma-separated file names. A file name can be ... a path to a JAR file
contained in the bundle’s JAR file."
The classpath entry would be something like:
Bundle-Classpath .,json.jar
That bundle can then export the packages of json.jar making them available to
all. It is a wrapper.
Is org.restlet.ext.json intended to be the wrapper but not quite there yet or
is there something else I am missing or need to look at?
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