OSGi bundle MANIFEST file is core resource of bundle
and we can say its bundle deployment configuration file. OSGi containers will
read the information from MANIFEST file and do subsequent actions. We can use
many standard OSGi bundle headers in bundle MANIFEST file. Each header have
their own significant meaning. Bundle header and its value separated with colon:
The following are headers which proposed by OSGi
Alliance. We have other vendor specific headers like Eclipse Foundation, Spring Source and aQute.
OSGi
Alliance Standard Headers
The headers proposes by OSGi alliance supported by all
OSGi implementation environments like Apache
Felix, Equinox and Knopflerfish.
Bundle-ActivationPolicy
Bundle-ActivationPolicy will notify to the container
when should bundle available to use or activated. Usually when we deploy bundle,
it is immediately available.
Bundle-ActivationPolicy value is lazy it means when bundle will get first request then bundle will
be activated.
Example:
Bundle-ActivationPolicy:
lazy
|
Bundle-Activator
Bundle-Activator header specify the bundle activator
java class. Bundle Activator is java class, which manage the bundle life cycle.
Each bundle must have activator class and OSGi container invoke the lifecycle
methods based on bundle lifecycle stages.
Example:
Bundle-Activator
: com.liferaysavvy.bundle.Activator
|
Bundle-Classpath
Bundle-Classpath is list of values separated by comma delimiter.
The values may be jar files or directories and directories have jar files or
java classes. Bundle will look for required classes in the given location.
Example:
Bundle-Classpath
: apache-commons.jar, apache-logs.jar
OR
Bundle-Classpath
: .,WEB-INF/classes,foo1.jar
OR
Bundle-ClassPath:
., A.jar, B.jar, C.jar
|
Note:
The values separated by comma and dot will specify the
current bundle directory.
Bundle-ContactAddress
Bundle-ContactAddress its just information which will
use to contact bundle vendors. It’s some text or may be company URL
Example:
Bundle-ContactAddress
: Liferay Savvy India
OR
Bundle-ContactAddress
: http://www.liferaysavvy.com
|
Bundle-Copyright
Bundle-Copyright is just copyright information.
Bundle-Description
Bundle-Description is description about bundle and its
simple human readable text.
Bundle-License
Bundle-License specify the license information of
bundle and it is a text.
Bundle-ManifestVersion:
This header is required and marks the jar as a bundle,
the value is always 2 (newer OSGi specifications might add more features in
which case the number would be increased).
Value 1 indicates OSGi release 3
Value 2 indicate OSGi release 4
Example:
Bundle-ManifestVersion
: 2
|
Bundle-Name:
Bundle-Name is human readable name for bundle.
Example:
Bundle-Name:
LSServiceProvider
|
Bundle-SymbolicName
Bundle-SymbolicName is unique identification name for
bundle. This name will used by other bundle when they have dependency.
Example:
Bundle-SymbolicName:
com.ls.de.LSServiceProvider
|
Bundle-Vendor
Bundle-Vendor is vendor name who implemented the bundle.
Example:
Bundle-Vendor
: Liferay Savvy
|
Bundle-RequiredExecutionEnvironment
Bundle-RequiredExecutionEnvironment is specify the JRE
execution environment.
Example:
Bundle-RequiredExecutionEnvironment:
JavaSE-1.8
OR
Bundle-RequiredExecutionEnvironment:
JavaSE-1.7
OR
Bundle-RequiredExecutionEnvironment:
JavaSE-1.6
|
Bundle-Version
Bundle-Version specify the version number for bundle.
Example:
Bundle-Version:
1.0.0.qualifier
OR
Bundle-Version:
1.0.0
|
Export-Package
Export-Package contains list of java packages
separated by comma delimiter that will be exported and available to other
bundles. Only the packages specified by the header will be exported, the rest
will be private and will not be seen outside the bundle.
Example:
Export-Package:
com.ls.de.lsserviceprovider.services
OR
Export-Package:org.springframework.core.task;uses:="org.springframework.core,org.springframework.util";version=2.5.1
org.springframework.core.type;uses:=org.springframework.core.annotation;version=2.5.1[...]
|
Export-Service
Export-Service specify the services, which are
exported from the bundle, and it will be available to other bundles. List separated
by comma delimiter. This header will work when we work with multiple bundles
and there is dependency between each other.
Example:
Export-Service:
org.osgi.service.log.LogService,org.osgi.service.log.LogReaderService
|
Import-Package
Import-Package specify the list of bundle packages,
which required in the current working bundle. What are the packages exported by
other bundles, can import in the current bundle with help of Import-Package
header. This header will work when we work with multiple bundles and there is
dependency between each other.
Example:
Import-Package:
com.ls.de.lsserviceprovider.services
OR
Import-Package:org.apache.commons.logging,edu.emory.mathcs.backport.java.util.concurrent;resolution:=optional[...]
|
Import-Service
Import-Service is similar to Export-service but it is
vice versa. The list of service class names which required by the bundle.
Services which are already exported can use in the list.
Example:
Import-Service:
org.osgi.service.log.LogService,org.osgi.service.log.LogReaderService
|
Provide-Capability
More
details you can found here
|
Require-Bundle
Require-Bundle specify the dependency on other bundle.
The bundle we specified in the header must be required to activate current
bundle. This bundle similar to Import-Bundle header proposed by Spring Source.
Example:
Require-Bundle:
org.example.foo; bundle-version=3.0,org.example.bar; bundle-version=1.0
|
The following are very important headers and we use
very regular in the OSGi bundle development.
Manifest-Version
Bundle-ManifestVersion
Bundle-Name
Bundle-SymbolicName
Bundle-Version
Bundle-Activator
Bundle-Vendor
Bundle-RequiredExecutionEnvironment
Export-Package
Import-Package
|
Spring Source MANIFEST headers
The following are Spring Source proposed MANIFEST
headers. To use these headers we must have vendor specific implementation
bundle in the OSGi container.
Import-Bundle
Import-Bundle is similar to Require-Bundle proposed by
OSGi Alliance and both are same meaning.
Example:
Import-Bundle:
org.example.foo; bundle-version=3.0,org.example.bar; bundle-version=1.0
|
Web-ContextPath.
The default context from which the web content is
hosted. You must set the value of the Web-ContextPath header to the value of
the <context-root> element for the corresponding web module in the
application.xml file. The presence of this header identifies this bundle as a
web application bundle.
Example:
Web-ContextPath:
/contextRoot
|
Web-DispatcherServletUrlPatterns
Web-DispatcherServletUrlPatterns specify the URL
patterns for Dispatcher servlet.
Example:
Web-DispatcherServletUrlPatterns
: /spring/*
|
Web-FilterMappings
Web-FilterMappings specify the application filter
mappings
Example:
Web-FilterMappings : /secure/*
|
aQute
MANIFEST headers
The following are aQute
proposed MANIFEST headers. To use these headers we must have vendor specific
implementation bundle in the OSGi container.
Include-Resource
Include-Resource is path where bundle resource files
are available like properties files
Example
Include-Resource:
src/main/resources
|
Private-Package
List of packages, which are specific, the current
bundle and it will not be available outside. Other bundles cannot access these
packages. This header will used in bnd tools developed OSGi environment. Usually
we specify the bundle services implementation packages in the list.
Example:
Private-Package:
com.ls.de.lsserviceprovider.services.impl
|
Eclipse
Foundation MANIFEST headers
The following are Eclipse
Foundation proposed MANIFEST headers. To use these headers we must have
vendor specific implementation bundle in the OSGi container. Equinox
implementation support these headers.
The following are headers proposed by Eclipse Foundation.
Eclipse-BuddyPolicy
Eclipse-BundleShape
Eclipse-ExtensibleAPI
Eclipse-PlatformFilter
Eclipse-RegisterBuddy
|
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