Comments on: Understanding the OSGi uses Directive http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/ The voice of SpringSource Sat, 20 Mar 2010 12:14:29 -0500 http://wordpress.org/?v=2.8.5 hourly 1 By: “Uses” Directive In OSGi « rossenstoyanchev.org Blog http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/comment-page-1/#comment-169455 “Uses” Directive In OSGi « rossenstoyanchev.org Blog Sun, 15 Nov 2009 21:52:19 +0000 http://blog.springsource.com/?p=462#comment-169455 [...] blog by Glyn Normington that explains the basic problem (note the comments section where he suggests [...] [...] blog by Glyn Normington that explains the basic problem (note the comments section where he suggests [...]

]]> By: Cloning in dm Server 2.0 M3 | SpringSource Team Blog http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/comment-page-1/#comment-167255 Cloning in dm Server 2.0 M3 | SpringSource Team Blog Wed, 10 Jun 2009 15:21:35 +0000 http://blog.springsource.com/?p=462#comment-167255 [...] by OSGi resolver failures, in particular violations of uses constraints (as explained in an earlier blog). Some uses constraint violations cannot be avoided by cloning, but we can't tell until [...] [...] by OSGi resolver failures, in particular violations of uses constraints (as explained in an earlier blog). Some uses constraint violations cannot be avoided by cloning, but we can't tell until [...]

]]> By: SpringSource Team Blog » SpringSource dm Server Roadmap http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/comment-page-1/#comment-163932 SpringSource Team Blog » SpringSource dm Server Roadmap Mon, 20 Apr 2009 13:34:24 +0000 http://blog.springsource.com/?p=462#comment-163932 [...] it wires to the same EclipseLink bundle as Spring 2.5.6. More on uses can be found in Glyn's introduction blog and my blog on diagnosing uses [...] [...] it wires to the same EclipseLink bundle as Spring 2.5.6. More on uses can be found in Glyn's introduction blog and my blog on diagnosing uses [...]

]]> By: SpringSource Team Blog » Our plans for building OSGi applications http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/comment-page-1/#comment-151775 SpringSource Team Blog » Our plans for building OSGi applications Wed, 18 Mar 2009 16:59:05 +0000 http://blog.springsource.com/?p=462#comment-151775 [...] manifest and what versions they have. Importantly, the generation process will correctly generate uses metadata for you, removing one of the most tedious [...] [...] manifest and what versions they have. Importantly, the generation process will correctly generate uses metadata for you, removing one of the most tedious [...]

]]> By: Glyn Normington http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/comment-page-1/#comment-133448 Glyn Normington Tue, 23 Dec 2008 13:21:34 +0000 http://blog.springsource.com/?p=462#comment-133448 The Uses directive will not help in this scenario. (The only way bundle C can access distinct types of package P when P is split across bundles A and B is by using require-bundle: A,B. However, that is not something I would recommend as split packages are complex and error-prone. If you would like to discuss the requirement further, please post to the dm Server forums.) The Uses directive will not help in this scenario.

(The only way bundle C can access distinct types of package P when P is split across bundles A and B is by using require-bundle: A,B. However, that is not something I would recommend as split packages are complex and error-prone. If you would like to discuss the requirement further, please post to the dm Server forums.)

]]> By: Vishalj http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/comment-page-1/#comment-133437 Vishalj Tue, 23 Dec 2008 12:44:48 +0000 http://blog.springsource.com/?p=462#comment-133437 I have a requirement Bundle A exporting package P with some interface Bundle B exporting package P with different interface Bundle C requiring service from both the bundles is it possible or shall i change the version number Will uses directive help me in anyway I have a requirement
Bundle A exporting package P with some interface
Bundle B exporting package P with different interface
Bundle C requiring service from both the bundles
is it possible or shall i change the version number

Will uses directive help me in anyway

]]> By: Glyn Normington http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/comment-page-1/#comment-132688 Glyn Normington Thu, 18 Dec 2008 17:07:26 +0000 http://blog.springsource.com/?p=462#comment-132688 If you really wanted B to use the older version of F, then you'd have to modify C so it could also use that version. Note that the uses directive is preventing runtime errors, such as class cast exceptions, from occurring where incompatible types from two versions of the org.foo package conflict. A more significant change would be to rework bundle B so that org.foo types no longer "leak out" via org.bar types. Then you could delete the uses directive and B and C could use distinct versions of the package org.foo. (Thanks for spotting my typo. - I have edited the blog.) If you really wanted B to use the older version of F, then you'd have to modify C so it could also use that version. Note that the uses directive is preventing runtime errors, such as class cast exceptions, from occurring where incompatible types from two versions of the org.foo package conflict.

A more significant change would be to rework bundle B so that org.foo types no longer "leak out" via org.bar types. Then you could delete the uses directive and B and C could use distinct versions of the package org.foo.

(Thanks for spotting my typo. – I have edited the blog.)

]]> By: Lofi Dewanto http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/comment-page-1/#comment-131651 Lofi Dewanto Tue, 09 Dec 2008 12:22:49 +0000 http://blog.springsource.com/?p=462#comment-131651 Thanks a lot for a good intro to "uses" directive... You wrote: "Stepping back from the detail, we know that the uses conflict is due to bundle C importing a different version of package org.foo than that imported by bundle C (Maybe bundle B?). Something must be causing different versions to be used and when we check the package imports carefully, we realise that we forgot to upgrade B to use the latest version of F". My question: What if I want *explicitly* that B should use the older version of F? How can I reach this? I described my problem with versioning of bundles with Spring dm here in Spring forum: http://forum.springsource.org/showthread.php?t=64480 Thanks, Lofi. Thanks a lot for a good intro to "uses" directive…

You wrote:
"Stepping back from the detail, we know that the uses conflict is due to bundle C importing a different version of package org.foo than that imported by bundle C (Maybe bundle B?). Something must be causing different versions to be used and when we check the package imports carefully, we realise that we forgot to upgrade B to use the latest version of F".

My question:
What if I want *explicitly* that B should use the older version of F? How can I reach this?

I described my problem with versioning of bundles with Spring dm here in Spring forum:
http://forum.springsource.org/showthread.php?t=64480

Thanks,
Lofi.

]]> By: SpringSource Team Blog » Diagnosing OSGi uses conflicts http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/comment-page-1/#comment-130134 SpringSource Team Blog » Diagnosing OSGi uses conflicts Sat, 22 Nov 2008 21:47:05 +0000 http://blog.springsource.com/?p=462#comment-130134 [...] on November 22nd, 2008 by Rob Harrop in Spring. In his recent blog entry, Glyn provided an introduction to the OSGi "uses" directive. In this blog, I want to dig [...] [...] on November 22nd, 2008 by Rob Harrop in Spring. In his recent blog entry, Glyn provided an introduction to the OSGi "uses" directive. In this blog, I want to dig [...]

]]> By: Glyn Normington http://blog.springsource.com/2008/10/20/understanding-the-osgi-uses-directive/comment-page-1/#comment-125960 Glyn Normington Wed, 22 Oct 2008 07:36:38 +0000 http://blog.springsource.com/?p=462#comment-125960 Agreed. Tools like bnd certainly make it easier to maintain correct manifests. Agreed. Tools like bnd certainly make it easier to maintain correct manifests.

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