OSGI捆绑无法启动

Question

I have an OSGI bundle which gets to the RESOLVED state, but never reaches the ACTIVE state. When I run my application, this is the stacktrace I am obtaining: http://tny.cz/fa949f16

Afterwards, when I try to start the bundle explicitly through the OSGI console, I get this error:

start 53
gogo: BundleException: The activator rsy.home.mac.sm.schedule.service.win.WinServiceActivator for bundle rsy.home.mac.sm.schedule.service.win is invalid

Notice that in the end of the stacktrace ouput, there's the following message:

!ENTRY org.eclipse.osgi 4 0 2014-03-14 10:52:50.984 !MESSAGE Bundle rsy.home.mac.sm.schedule.service.win_1.0.0 [53] is not active.

Here's the code from WinServiceActivator:

package rsy.home.mac.sm.schedule.service.win;

import java.util.HashMap;

import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleEvent;
import org.osgi.framework.BundleListener;


public class WinServiceActivator implements BundleActivator {

    private static BundleContext context;

    @Override
    public void start(BundleContext context) throws Exception {

        ServiceActivator.context = context;

        ScheduleService schedServ = new ScheduleService();

        schedServ.setTdMapping(new HashMap<String, String>());
        schedServ.setHtMapping(new HashMap<String, String>());
        schedServ.setDoMapping(new HashMap<String, String>());

        context.registerService(ScheduleService.class.getName(), 
                schedServ, null);
    }

    @Override
    public void stop(BundleContext context) throws Exception {

        context.ungetService(context.getServiceReference(ScheduleService.class.getName()));
        ServiceActivator.context = null;
    }
}

And this is my MANIFEST file:

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: SM Schedule Query Service
Bundle-SymbolicName: rsy.home.mac.sm.schedule.service.sm;singleton:=true
Bundle-Version: 1.0.0
Bundle-RequiredExecutionEnvironment: JavaSE-1.6
Service-Component: OSGI-INF/sm_schedule_service.xml
Require-Bundle: rsy.home.mac.sm.jaxrs.lib;bundle-version="1.0.0",
 rsy.home.mac.sm.config;bundle-version="0.1.0",
 rsy.home.mac.log,
 rsy.home.mac.sm.model;bundle-version="1.0.0",
 rsy.home.mac.sm.schedule.service;bundle-version="1.0.0",
 rsy.home.mac.sm.sm.scheduletable;bundle-version="1.0.0",
 resources;bundle-version="1.0.0",
 rsy.home.mac.portal.utilities,
 rsy.home.mac.portal.logging;bundle-version="1.0.0",
 org.eclipse.xsd;bundle-version="2.7.0",
 org.eclipse.osgi
Import-Package: org.osgi.service.http;version="1.2.1"
Bundle-ActivationPolicy: lazy
Bundle-Activator: rsy.home.mac.sm.schedule.service.sm.SmServiceActivator
Export-Package: rsy.home.mac.sm.schedule.service.sm

While googling the error "Activator start error, ClassCastException: xxxx cannot be cast to org.osgi.framework.BundleActivator", I found this:

That error is telling you that you have two copies of the BundleActivator class loaded into your VM somehow. The framework is using one and your bundle is using another.

Do you have any other bundles exporting org.osgi.framework? Where is your bundle getting this package from? If you issue the following command in the Felix shell you can see the wiring:

inspect package requirement <bundle-id>

or shortened to:

inspect p r <bundle-id>

Where <bundle-id> is the ID of your bundle, then you should see from where it is getting org.osgi.framework. If it is not the system bundle (org.apache.felix.framework), then you have an issue.

When I executed the given command, I obtained this output:

org.osgi.framework; version="1.7.0" -> org.eclipse.osgi_3.9.0.v20130410-1557 [0]

Do you think this is the reason why the bundle doesn't start? If so, how can I fix this? Following this comment I found on the internet and the comments and answers from people below, I tried to replace this line in the MANIFEST file:

Import-Package: org.osgi.service.http;version="1.2.1"

by this one:

Import-Package: org.osgi.framework

And I get a whole bunch of errors in the code, whose reason given by Eclipse is:

Multiple markers at this line - Access restriction: The type BundleActivator is not accessible due to restriction on required library rsy.home.mac.sm.jaxrs.lib/lib/org.osgi.core-4.2.0.jar - Access restriction: The type BundleListener is not accessible due to restriction on required library rsy.home.mac.sm.jaxrs.lib/lib/org.osgi.core-4.2.0.jar

I would really appreciate some help on this... Thanks!

Answer 1

I had a similar exception some time ago when I tried to get CXF working in an eclipse rcp application. The reason was that I did require bunddle on org.eclipse.osgi. You should avoid that.

Require bundle means that you import all packages of that bundle. The framework bundle (org.eclipse.osgi) exports the OSGi API. Probably another bundle listed in your require bundle list also exports the BundleActivator package. So you get the class from two sources and likely use a different one than the framework itself.

These problems are the reqson why you should avoid require bundle. Espcially try to avoid doing require bundle on org.eclipse.osgi. THis bundle also exports all packages defined in the system exports. So it exports lots of packages and chances are high you run into problems. In my case with cxf I had a similar problem with the jaxb api that is exported by org.eclipse.osgi and also by one of the bundles cxf brings with it.

This article may give you some more details as the problem you observe often surfaces as a uses constraint violation. http://njbartlett.name/2011/02/09/uses-constraints.html

In general if you have the chance use the maven bundle plugin or bndtools to generate the Manifest. Both have good defaults that avoid most of these problems.