Using the OSGi API, how do I find out if a given bundle is a fragment?

Question

In the OSGi API, a call to BundleContext.getBundles() returns all bundles, whether they are fragments or not. For a given Bundle object, what is the best way to tell if this is a fragment or not?

score 9 · Accepted Answer · answered Jul 25 '12 at 21:47

9

Best way:

(bundle.adapt(BundleRevision.class).getTypes() & BundleRevision.TYPE_FRAGMENT) != 0

answered Jul 25 '12 at 21:47

BJ Hargrave

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1

Yeah, that's much more explicit than my way. Thanks! – Dan Gravell Jul 26 '12 at 08:23
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Be aware that this is a new API in OSGi 4.3. Also be aware that adapt() can return null if you lose the race condition just as the bundle is being uninstalled. – Chris Dolan Jul 26 '12 at 14:37

score 4 · Answer 2 · answered Jul 25 '12 at 17:30

4

One possible way: use Bundle.getHeaders() to look for the Fragment-Host header. If it is present, it's a fragment.

answered Jul 25 '12 at 17:30

Dan Gravell

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Answering my own question for now with the best way I know of... if this is wrong or there are better ways I will award the answer elsewhere! – Dan Gravell Jul 25 '12 at 17:31

score 1 · Answer 3 · answered Apr 04 '13 at 14:43

According to the OSGi Core Specification Release 4, Version 4.2, there is also the PackageAdmin service, which provides access to the structural information about bundles, e.g. determine whether a given bundle is a fragment or not.

import org.osgi.framework.Bundle;
import org.osgi.service.packageadmin.PackageAdmin;

PackageAdmin packageAdmin = ...; // I assume you know this

Bundle hostBundle = ...;         // I assume you know this
Bundle fragmentBundle = ...;     // I assume you know this

assertFalse(PackageAdmin.BUNDLE_TYPE_FRAGMENT, packageAdmin.getBundleType(hostBundle);
assertEquals(PackageAdmin.BUNDLE_TYPE_FRAGMENT, packageAdmin.getBundleType(fragmentBundle);

Apparently, in OSGi 4.3, the PackageAdmin service seems to be deprecated and should be replaced by the org.osgi.framework.wiring package.

Using the OSGi API, how do I find out if a given bundle is a fragment?

3 Answers3