-metainf-services

Analyzer

The -metainf-services instruction tells bnd how files in the META-INF/services should be processed. See the chapter about META-INF/services Annotations how to apply Bundle annotations to the files in the META-INF/services.

This instruction can have the following values:

• annotation (default if not set): Scan META-INF/services files and only process those files which contain at least one textual annotations.
• auto: The convenience strategy. Scans META-INF/services files and auto-registers implementations in services files which do not have a single textual annotation. The latter means that bnd behaves as if there was a aQute.bnd.annotation.spi.ServiceProvider annotation present on each implementation. This is useful if you just want to have bnd generate the Provide-Capability headers for osgi.serviceloader. Additionally auto behaves like annotation and would process all other files with textual annotations.
• none: skip processing of files in META-INF/services completely

Example of auto-registration

Assume we want to wrap a non-OSGi library containing META-INF/services. Create bnd.bnd file and put a library having a META-INF/services folder e.g. groovy-3.0.22.jar in a local lib folder. We will use -includeresource: @lib/groovy-3.0.22.jar to unroll the jar.

# bnd.bnd
-includeresource: @lib/groovy-3.0.22.jar
-metainf-services: auto

This creates a new jar with the following MANIFEST.MF headers from the META-INF/services folder:

# MANIFEST.MF
Provide-Capability                      osgi.service;objectClass:List<String>="org.codehaus.groovy.transform.ASTTransformation";effective:=active
                                        osgi.serviceloader;osgi.serviceloader="org.codehaus.groovy.transform.ASTTransformation";register:="groovy.grape.GrabAnnotationTransformation"
Require-Capability                      osgi.ee;filter:="(&(osgi.ee=JavaSE)(version=1.8))"
                                        osgi.extender;filter:="(&(osgi.extender=osgi.serviceloader.registrar)(version>=1.0.0)(!(version>=2.0.0)))";resolution:=optional

Because -metainf-services: auto is used, it instructs bnd to auto-generate a @ServiceProvider annotation under the hood for services without annotations. To prevent the latter (auto-generation) use the default -metainf-services: annotation (to process only textual annotations) or use -metainf-services: none to skip processing of META-INF/services files completely.

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