Editing OSGi (section)

==Bundles==
[[Image:osgi-system-layering.svg|thumb|upright=1.35|Classification: OSGi]]

A bundle is a group of Java classes and additional resources equipped with a detailed manifest <code>[[MANIFEST.MF]]</code> file on all its contents, as well as additional services needed to give the included group of Java classes more sophisticated behaviors, to the extent of deeming the entire aggregate a component.

Below is an example of a typical <code>[[MANIFEST.MF]]</code> file with OSGi Headers:
<syntaxhighlight lang="properties" line>
 Bundle-Name: Hello World
 Bundle-SymbolicName: org.wikipedia.helloworld
 Bundle-Description: A Hello World bundle
 Bundle-ManifestVersion: 2
 Bundle-Version: 1.0.0
 Bundle-Activator: org.wikipedia.Activator
 Export-Package: org.wikipedia.helloworld;version="1.0.0"
 Import-Package: org.osgi.framework;version="1.3.0"
</syntaxhighlight>
The meaning of the contents in the example is as follows:<ref>[http://blog.springsource.com/2008/02/18/creating-osgi-bundles/ Creating OSGi bundles] by Costin Leau</ref>

# '''Bundle-Name:''' Defines a human-readable name for this bundle, Simply assigns a short name to the bundle.
# '''Bundle-SymbolicName:''' The only required header, this entry specifies a unique identifier for a bundle, based on the [[Reverse domain name notation|reverse domain name convention]] (used also by the [[java packages]]).
# '''Bundle-Description:''' A description of the bundle's functionality.
# '''Bundle-ManifestVersion:''' Indicates the OSGi specification to use for reading this bundle.
# '''Bundle-Version:''' Designates a version number to the bundle.
# '''Bundle-Activator:''' Indicates the class name to be invoked once a bundle is activated.
# '''Export-Package:''' Expresses which Java packages contained in a bundle will be made available to the outside world.
# '''Import-Package:''' Indicates which Java packages will be required from the outside world to fulfill the dependencies needed in a bundle.