Specifies that a bundle provides a set of Capabilities,

• Example: Provide-Capability: com.acme.dictionary; from:String=nl; to=de; version:Version=3.4

• Pattern: .*

Options

• effective: (resolve) Specifies the time a capabiltity is available, either resolve (default) or another name. The OSGi framework resolver only considers Capabilities without an effective directive or effective:=resolve. Capabilties with other values for the effective directive can be considered by an external agent.

  • Example: effective:=resolve

  • Values: resolve or another word

  • Pattern: .*

• uses: The uses directive lists package names that are used by this Capability. This information is intended to be used for uses constraints.

  • Example: uses:='foo,bar,baz'

  • Pattern: .*

Provide-Capability

The Provide-Capability header declares that a bundle provides one or more OSGi capabilities. Capabilities are used by the OSGi framework to match requirements from other bundles. Each capability can include a namespace, attributes, and directives.

Example:

Provide-Capability: osgi.service;objectClass=com.example.MyService;version=1.0.0

This header is used for advanced modularity and service scenarios, and is typically generated by annotations or build tooling.

		Parameters capabilities = new Parameters(annotationHeaders.getHeader(PROVIDE_CAPABILITY));


	/*
 * Provide-Capability header
 */
private void doProvideCapability(ProvideCapability annotation) {
	StringBuilder sb = new StringBuilder(annotation.ns());
	if (annotation.name() != null)
		sb.append(";").append(annotation.ns()).append("='").append(annotation.name()).append("'");
	if (annotation.uses() != null)
		sb.append(";").append("uses:='").append(Strings.join(",", annotation.uses())).append("'");
	if (annotation.mandatory() != null)
		sb.append(";").append("mandatory:='").append(Strings.join(",", annotation.mandatory())).append("'");
	if (annotation.version() != null)
		sb.append(";").append("version:Version='").append(annotation.version()).append("'");
	if (annotation.value() != null)
		sb.append(";").append(annotation.value());
	if (annotation.effective() != null)
		sb.append(";effective:='").append(annotation.effective()).append("'");

	add(Constants.PROVIDE_CAPABILITY, sb.toString());
}




		package aQute.bnd.annotation.headers;
	
	import java.lang.annotation.*;

	/**
	 * Define a Provide Capability clause in the manifest.
	 * <p>
	 * Since this annotation can only be applied once, it is possible to create an annotation
	 * that models a specific capability. For example:
	 * <pre>
	 * interface Webserver {
	 * 		@ProvideCapability(ns="osgi.extender", name="aQute.webserver", version = "${@version}")
	 * 	 	@interface Provide {}
	 * 
	 * 		@RequireCapability(ns="osgi.extender", filter="(&(osgi.extender=aQute.webserver)${frange;${@version}})")
	 * 	 	@interface Require {}
	 * }
	 * 
	 * Webserver.@Provide
	 * public class MyWebserver {
	 * }
	 * </pre>
	 * 
	 */
	@Retention(RetentionPolicy.CLASS)
	@Target({
			ElementType.ANNOTATION_TYPE, ElementType.TYPE
	})
	public @interface ProvideCapability {
		/**
		 * Appended at the end of the clause (after a ';'). Can be used to add
		 * additional attributes and directives.
		 */
		String value() default "";
	
		/**
		 * The capability namespace. For example: {@code osgi.contract}.
		 */
		String ns();
	
		/**
		 * The name of the capability. If this is set, a property will be added as
		 * {ns}={name}. This is the custom pattern for OSGi namespaces. Leaving this
		 * unfilled, requires the {@link #value()} to be used to specify the name of
		 * the capability, if needed. For example {@code aQute.sse}.
		 */
		String name() default "";
	
		/**
		 * The version of the capability. This must be a valid OSGi version.
		 */
		String version() default "";
	
		/**
		 * Effective time. Specifies the time a capability is available, either
		 * resolve (default) or another name. The OSGi framework resolver only
		 * considers Capabilities without an effective directive or
		 * effective:=resolve. Capabilities with other values for the effective
		 * directive can be considered by an external agent.
		 */
		String effective() default "resolve";
	
		/**
		 * The uses directive lists package names that are used by this Capability.
		 * This information is intended to be used for <em>uses constraints</em>,
		 */
		String[] uses() default {};
	
		/**
		 * Mandatory attributes. Forces the resolver to only satisfy filters that
		 * refer to all listed attributes.
		 */
		String[] mandatory() default {};
	}
		
		
		
				verifyDirectives(Constants.PROVIDE_CAPABILITY, "effective:|uses:", null, null);
				
				
				
				
		private void verifyCapabilities() {
	Parameters map = parseHeader(manifest.getMainAttributes().getValue(Constants.PROVIDE_CAPABILITY));
	for (String key : map.keySet()) {
		Attrs attrs = map.get(key);
		verify(attrs, "cardinality:", CARDINALITY_PATTERN, false, "Requirement %s cardinality not correct", key);
		verify(attrs, "resolution:", RESOLUTION_PATTERN, false, "Requirement %s resolution not correct", key);

		if (key.equals("osgi.extender")) {
			verify(attrs, "osgi.extender", SYMBOLICNAME, true,
					"Extender %s must always have the osgi.extender attribute set", key);
			verify(attrs, "version", VERSION, true, "Extender %s must always have a version", key);
		} else if (key.equals("osgi.serviceloader")) {
			verify(attrs, "register:", PACKAGEPATTERN, false,
					"Service Loader extender register: directive not a fully qualified Java name");
		} else if (key.equals("osgi.contract")) {
			verify(attrs, "osgi.contract", SYMBOLICNAME, true,
					"Contracts %s must always have the osgi.contract attribute set", key);

		} else if (key.equals("osgi.service")) {
			verify(attrs, "objectClass", MULTIPACKAGEPATTERN, true,
					"osgi.service %s must have the objectClass attribute set", key);

		} else if (key.equals("osgi.ee")) {
			// TODO
		} else if (key.startsWith("osgi.wiring.") || key.startsWith("osgi.identity")) {
			error("osgi.wiring.* namespaces must not be specified with generic requirements/capabilities");
		}

		verifyAttrs(attrs);

		if (attrs.containsKey("filter:"))
			error("filter: directive is intended for Requirements, not Capability %s", key);
		if (attrs.containsKey("cardinality:"))
			error("cardinality: directive is intended for Requirements, not Capability %s", key);
		if (attrs.containsKey("resolution:"))
			error("resolution: directive is intended for Requirements, not Capability %s", key);
	}
}

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TODO Needs review - AI Generated content