On 10/27/15 11:27 , Balázs Zsoldos wrote:
@David:

I know about the *org.osgi.framework.system.**packages.extra* property, but
that is about another use-case.

*org.osgi.framework.system.**packages.extra *can be used to extend the list
of system packages.
*org.osgi.framework.system.**packages* can be used to reduce the list of
the system packages.

I want to reduce the list of system packages as some packages are coming
from bundles. More specifically, I want to list only those packages that I
actually need from the JDK. Reason: Many packages are incomplete or buggy
in the JDK: javax.transaction.*, javax.xml.*...

@Andy:

The text at
https://osgi.org/javadoc/r5/core/org/osgi/framework/Constants.html#FRAMEWORK_SYSTEMPACKAGES
  says:* Framework launching property identifying packages which the system
bundle must export.*

"Must" does not mean that only those packages should be exported by the
system bundle.

@Everyone:

Questions:

    - What is the exact meaning of system packages from the perspective of
    this setting? In my opinion, the list of packages that are coming outside
    the OSGi container.

That is not my interpretation. System packages are those packages provided by the system bundle. From a wiring perspective, all of the JRE packages look like they are coming from the system bundle just like the OSGi core packages, so your distinction doesn't really make sense to me.


org.osgi.* packages do not come outside from the OSGi
    container.
    - Could the org.osgi.* packages come from custom bundles? I think, no.
    - Can you write an application that does not need any of the org.osgi.*
    package? I think you cannot.At least one bundle has to implement an
    Activator to have any kind of functionality in the system. Otherwise the
    bundles will be resolved, but they will do nothing (not even a static block
    will be called).

Wrong. The extender pattern is based almost wholly around such an approach.

-> richard

    - Can you imagine any use-case where exporting org.osgi.* packages by
    the system bundle could cause any issue? I cannot.
    - Is it an extra work that org.osgi.* packages have to be appended if
    system.packages are overridden? Yes, always.

If we answer these questions, we will come to the conclusion (at least I :)
) that org.osgi.* packages should always be exported by the system bundle.
They are not in the scope of the meaning of system.packages setting.


Kind regards,
*Balázs **Zsoldos*


On Tue, Oct 27, 2015 at 3:21 PM, David Bosschaert <
david.bosscha...@gmail.com> wrote:

Yes, that's precisely what the
org.osgi.framework.system.packages.extra was designed for. That way
you don't need to remember what the framework puts on
org.osgi.framework.system.packages in order to augment it.

Best regards,

David

On 27 October 2015 at 14:18, Andy Lee <thelees.a...@gmail.com> wrote:
If you are trying to extend the set of packages exported by the system
bundle, you should use org.osgi.framework.system.packages.extra.  By
specifying org.osgi.framework.system.packages you are overriding the
default value used by the framework, and hence must include the packaged
that are expected to be supplied by the framework.

See

https://osgi.org/javadoc/r5/core/org/osgi/framework/Constants.html#FRAMEWORK_SYSTEMPACKAGES

--Andy



On Tue, Oct 27, 2015 at 10:00 AM, Balázs Zsoldos <
balazs.zsol...@everit.biz>
wrote:

Hi,

I asked this 1-2 years ago, but I think it is worthy to  ask it again.

Are you sure that the set of system packages should include the OSGi
core
packages?

In my understanding:

    - system packages are the ones coming from outside of the OSGi
container
    - osgi core packages are offered by the framework bundle, but they
are
    not system packages

In practice:

    - If I specify org.osgi.system.packages property for equinox, I do
not
    have to define the packages implemented by the framework
    - If I specify the same property for felix, I must copy-paste the
    packages of osgi.core always

Do you think there is a use-case when osgi.core packages offered by the
framework should be excluded from the exported packages of the system
bundle? I think Equinox has the right behavior here.

Do you see any chance to change this behavior in the future?

Kind regards,
*Balázs **Zsoldos*

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