[eclipselink-dev] Use of Require-Bundle in EclipseLink OSGI bundles

[Mitesh Meswani <Mitesh.Meswani@xxxxxxx>]

Current EclipseLink OSGI bundles use Require-Bundle Manifest entries. 
Following are the entries by bundle.

From org.eclipse.persisetnce.core.jar

   Require-Bundle: javax.activation;resolution:=optional,javax.mail;resol
    ution:=optional,org.eclipse.persistence.antlr;resolution:=optional,or
    g.eclipse.persistence.asm;resolution:=optional,javax.ejb;resolution:=
    optional,javax.jms;resolution:=optional,javax.resource;resolution:=op
    tional,javax.transaction;resolution:=optional,javax.xml.stream;resolu
    tion:=optional,javax.persistence

From org.eclipse.persisetnce.jpa.jar

   Require-Bundle: org.eclipse.persistence.core;visibility:=reexport,syst
    em.bundle,javax.persistence;bundle-version="1.99.0";visibility:=reexp
    ort,javax.transaction

From org.eclipse.persisetnce.oracle.jar

   Require-Bundle: org.eclipse.persistence.core;visibility:=reexport,java
    x.resource

It is not good practice to use Require-Bundle. The bundles that referred 
above are not guaranteed to be available in all the environment that 
EclipseLink runs in. For example (i) system.bundle is not available 
under Felix. (ii) Various javax.* bundles above are not available under 
GlassFish. However, the packages that we want to import from those 
bundles are available under these environment. Using Import-Package 
instead is a better practice. See [1] and OSGI R4 Spec version 3.13.3 
for more details.

We should switch to using Import-Package.

Thanks,
Mitesh

[1] http://www.osgi.org/wiki/uploads/Conference/OSGiBestPractices.pdf, 
slide 14