Re: [equinox-dev] NPE from RegistryStrategyOSGI.onStop()

[Simon J Archer <sarcher@xxxxxxxxxx>]

Looking in your manifest.mf I see this:

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: Test Plug-in
Bundle-SymbolicName: registry.test
Bundle-Version: 1.0.0
Bundle-Activator: registry.test.Activator
Bundle-Localization: plugin
Import-Package: org.osgi.framework;version="1.3.0"
Require-Bundle: org.eclipse.equinox.registry

Whenever you get a NoClassDefFoundError
that most likely cause is that you incorrectly defined the bundle's dependencies
in the manifest.mf.  Since the IExtensionRegistry class is in the
bundle org.eclipse.core.runtime you MUST do one of the following:

- Use the Import-Package header to declare
a dependency on the *package* org.eclipse.core.runtime.
- Use the Require-Bundle header to declare
your dependency on the *bundle* org.eclipse.core.runtime.

Either will work.  Sometimes it
is hard for people to decide which header to use.  My rule of thumb
is as follows:

- If you absolutely depend upon the
bundle then use Require-Bundle.  This is most often the case when
you are extending an extension-point defined in a particular bundle.  Since
there is never a possibility that another bundle could provide the extension
point on which you dependent it makes sense to always use Require-Bundle
for this sort of dependency.

- If all you care about is a code dependency
on a particular type in a particular package then use Import-Package.  This
is the case where you are depending on an implementer of some well defined
API and you really don't care who the provider is, so long as it provides
the correct API.  Use Import-Package when there could be multiple
exporters of the package on which  you depend, otherwise just use
Require-Bundle.

I hope this helps,

Simon

"Jason Hao" <jason.hao@xxxxxxxxx>
Sent by: equinox-dev-bounces@xxxxxxxxxxx

10/22/2006 10:54 PM

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Subject	Re: [equinox-dev] NPE from RegistryStrategyOSGI.onStop()

Oleg,

Thanks for you quick answer. I tried your suggestion but it didn't work
as you described. I added an activator class into MyBundle. MyBundle's
activator#start() is called after
org.eclipse.equinox.registry's. And so does the activator#stop().This is
even worse. Because I got another exception in MyBundle's activator#stop()
method.

java.lang.NoClassDefFoundError: org/eclipse/core/runtime/IExtensionRegistry
    at registry.test.Activator.stop(Activator.java:30)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl$3.run
(BundleContextImpl.java:1032)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.stop(BundleContextImpl.java:1028)
    at org.eclipse.osgi.framework.internal.core.BundleHost.stopWorker
(BundleHost.java:396)
    at org.eclipse.osgi.framework.internal.core.AbstractBundle.suspend(AbstractBundle.java:502)
    at org.eclipse.osgi.framework.internal.core.Framework.suspendBundle(Framework.java:1067)
    at org.eclipse.osgi.framework.internal.core.StartLevelManager.decFWSL(StartLevelManager.java:619)
    at org.eclipse.osgi.framework.internal.core.StartLevelManager.doSetStartLevel(StartLevelManager.java:283)
    at org.eclipse.osgi.framework.internal.core.StartLevelManager.shutdown
(StartLevelManager.java:256)
    at org.eclipse.osgi.framework.internal.core.SystemBundle.suspend(SystemBundle.java:190)
    at org.eclipse.osgi.framework.internal.core.Framework.shutdown(Framework.java:537)
    at org.eclipse.osgi.framework.internal.core.OSGi.shutdown(OSGi.java:61)
    at org.eclipse.osgi.framework.internal.core.FrameworkCommandProvider._shutdown(FrameworkCommandProvider.java:214)
    at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke (Method.java:597)
    at org.eclipse.osgi.framework.internal.core.FrameworkCommandInterpreter.execute(FrameworkCommandInterpreter.java:145)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.docommand(
FrameworkConsole.java:293)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.console(FrameworkConsole.java:278)
    at org.eclipse.osgi.framework.internal.core.FrameworkConsole.run(FrameworkConsole.java
:213)
    at java.lang.Thread.run(Thread.java:619)

I attached the test bundle for your reference.

On 10/21/06, Oleg Besedin <
obesedin@xxxxxxxxxx> wrote:

Hi Jason, 
The quick answer is that you need to stop your custom registry before org.eclipse.equinox.registry
bundle is stopped. 

Normally bundles are stopped in the reverse order of dependency, i.e.,
if a bundle MyBundle depends on the org.eclipse.equinox.registry, then
MyBundle is stopped first on shutdown, then org.eclipse.equinox.registry.
So, normally, you could put the code to stop your custom registry into
MyBundle's activator#stop(). 

I *guess* that putting inappropriate bundle start levels could break the
shutdown order. 

Thanks, 
Oleg

"Jason Hao" <jason.hao@xxxxxxxxx >
Sent by: equinox-dev-bounces@xxxxxxxxxxx

10/20/2006 03:52 AM

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To	equinox-dev@xxxxxxxxxxx
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Subject	[equinox-dev] NPE from RegistryStrategyOSGI.onStop()

Hi all,

I'm working on a project which is based on OSGi and equinox. The project
also includes equinox extension registry bundle. Since my extensions are
defined in files which are not in side the bundles, I need to load these
extensions into registry by IExtensionRegistry.addContribution() method.
And addContribution() method needs the master token which is under control
of equinox registry bundle and I can't get it, so I have to create my registry
instead of using the default registry. Here are what I have done. 

1.        Add "-Declipse.createRegistry=false"
into VM arguments. This will disable the default registry. 
2.        Create my extension registry
component and register it with declarative service spec. In the activate()
method I creat my OSGi strategy and registry. In the deactivate() method
I call IExtensionRegistry.stop() method to stop the registry. 
3.        Start my application
and the registry works well. 
4.        Shutdown the OSGi framework
by typing "shutdown" command in the console. org.eclipse.core.internal.registry.osgi.Activator.stop
() method is called and the bundle context is set to null. Then my registry
deactivate() method is called. I got java.lang.NullPointerException from
org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.onStop(RegistryStrategyOSGI.java
:204) since the bundle context is null. 
I wonder if there's any way I can work around. Thanks.

-- 
Best Regards,

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-- 
Best Regards,

Jason Hao [attachment "registry.test.zip" deleted by Simon J
Archer/Raleigh/IBM] _______________________________________________
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