org.osgi.annotation.bundle.Export Maven / Gradle / Ivy
/*
* Copyright (c) OSGi Alliance (2016). All Rights Reserved.
*
* Licensed under the Apache License, Export 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.osgi.annotation.bundle;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.osgi.annotation.versioning.ConsumerType;
import org.osgi.annotation.versioning.ProviderType;
import org.osgi.annotation.versioning.Version;
/**
* Mark a package to be exported from its bundle.
*
* The package must also be annotation with the {@link Version} annotation to
* specify the export version of the package.
*
* This annotation is not retained at runtime. It is for use by tools to
* generate bundle manifests or otherwise process the package.
*
* @author $Id: 8e77e5578eea93b272d22c0824d0e133c6ff44bf $
*/
@Documented
@Retention(RetentionPolicy.CLASS)
@Target(ElementType.PACKAGE)
public @interface Export {
/**
* A list of package names that are used by this package.
*
* If the {@code uses} directive must be omitted from the export package
* clause for this package, the empty value {} must
* be specified.
*
* If not specified, the {@code uses} directive for the export package
* clause is calculated by inspection of the classes in this package.
*/
String[] uses() default {};
/**
* A list of attribute or directive names and values.
*
* Each string should be specified in the form:
*
* - {@code "name=value"} for attributes.
* - {@code "name:type=value"} for typed attributes.
* - {@code "name:=value"} for directives.
*
* These are added, separated by semicolons, to the export package clause.
*/
String[] attribute() default {};
/**
* Specify the policy for substitutably importing this package.
*
* Bundles that collaborate require the same class loader for types used in
* the collaboration. If multiple bundles export packages with collaboration
* types then they will have to be placed in disjoint class spaces, making
* collaboration impossible. Collaboration is significantly improved when
* bundles are willing to import exported packages; these imports will allow
* a framework to substitute exports for imports.
*
* If not specified, the {@link Substitution#CALCULATED} substitution
* policy is used for this package.
*/
Substitution substitution() default Substitution.CALCULATED;
/**
* Substitution policy for this package.
*/
public enum Substitution {
/**
* Use a consumer type version range for the import package clause when
* substitutably importing a package.
*
* @see ConsumerType
*/
CONSUMER,
/**
* Use a provider type version range for the import package clause when
* substitutably importing a package.
*
* @see ProviderType
*/
PROVIDER,
/**
* The package must not be substitutably imported.
*/
NOIMPORT,
/**
* The policy value is calculated by inspection of the classes in the
* package.
*/
CALCULATED
}
}